Seemingly random lines on the surface I'm getting seemingly random lines scattered across the top surface of my prints:

Printer: Anycubic i3 mega
Slicer: Cura 3.2.1
Printer chosen in Cura: Prusa i3, Gcode flavor changed to RepRap
Cura Profile: Fine, "Outer before inner walls" enabled

What might be the reason?

This is the result of travel moves passing through/over the top surface. The combing setting can prevent this type of move (for walls, infill or top), and z-hop can avoid making any mark during these travels.

Both settings will affect speed. Z-hop will be active on every layer, for example.

It seems like the issue may only be that your nozzle has developed a bit of oozing.  The g code likes to repeat the same patterns for at least a few layers every time it changes patterns and if it does the same pattern on the top 3-4 layers than by the time it reaches the last layer on the top that pattern will actually be the slightest bit raised above the rest of the layers because of the ooze building up along the same pattern for how many ever layers it followed the same pattern. Your nozzle is than rubbing on that raised pattern when it completes the last layer.  This explains the randomness like OP said because the g code may not repeat the same pattern for 3 or more layers at the surface but without reading the gcode it would seemingly be random when and where they occurred.  And truthfully if its a small oozing you could reprint this and it could be gone if you changed almost any setting in cura because the g code would be recalculated differently and new patterns would be chosen but so long as the new gcode did not have the same pattern repeat itself on the top 3 or so layers you would not have these raised patterns for the nozzle to rub on when finishing the top last layer.


Ender 3 Extruder First Layer Perfect But Then Starts Clicking Afterwards All of a sudden I seem to be having a lot of issues with under extruding on my Ender 3. The bottom layer (of height 0.1 mm) prints perfectly fine. This is done at 15 mm/s speed. However, The moment the print moves to layer 2 and above (at the default speed of 60 mm/s), I start hearing a lot of clicking noise on the extruder.

So far I have tried the following

Replace nozzle to eliminate clogs
Cleaned the inside of the hot end assembly
Calibrated extruder steps/mm
Reduced the layer height from 0.3 mm to 0.2 mm
Reduced feed rate to as low at 50 %
Cleaned the filament feeder assembly and verified that it is able to push the filament properly (Extruding when the print is not happening works just fine with no clicking)

Even with all the above, the issue is still persisting. I am not what else could be causing this.

I am printing with PLA at 200 C

Not allowed to comment, so have to answer:

The temperature sensor is a thermally sensitive resistor. Unfortunately, the temperature is near the high limit of that sensor, and the manufacturing tolerances are very significant. That is why a temperature tower is important for each printer, as well as each filament. (I have 4 printers and each requires a different temperature for the same filament. My worst-case is out by 25 degrees! - it's the one I bought second-hand because the original purchaser couldn't get it to work. I could replace the NTC, but it is easier just to have settings to suit that printer.)
Filament does change over time. Lots of theories about why, but the practical response is to tune settings to suit the filament. The alternative is to modify the filament (eg drying, adding oil to surface, etc.), but even with really old filament, I've found adjusting settings (in the slicer, like Cura) to be the most generally workable solution.

Bottom line is to test, adjust settings and repeat until the system achieves the result you need. Treat most recommendations as serving suggestions, so use them as clues (but not rules) for the puzzles presented as 3D printing.

A temperature of 200 °C is fine. You probably have heat creep from a Bowden style extruder. The filament starts getting softer due to heat creeping up from the hot nozzle. Filament expands and clogs the tube causing gear clicking. Usually there is a heat sink at the  the Bowden tube connection. You need to cool that immediately. Which is, to set your fan to 100 % speed at layer height = 0. That should do the trick!


What is this called and where can I buy a replacement? In the image, there is an object circled in blue on the anet a8 printer that I need to buy a replacement of, however, I can not find it online, please help.

This is the throat block for direct drive extrusion, Anet8 is a cheap clone of Prusa printers, so it's easy to find parts for Anet printers.

This is one extruder kit that may help your needs, 1 Unidades Impresora 3D makerbot MK8 Extrusora De extrusión de Aluminio Bloque de DIY Kit para Reprap i3. This is a link for Aliexpress - of course there are other dealers.

Like @ZuOverture said the name of this component is the filament drive. Most of the manufactures sell the whole extrusion device already assembled, to avoid mismatches between the components of the extrusion device. If your device is somehow damaged, and without possibilities to be used in the printer the easiest solution would be to buy a new extrusion device. If financially is unfeasible for you, you may have the option to generate the 3D model of this piece and share the file to someone who could print this component for you.


Makerbot Replicator 2 Halts during print I am running a MakerBot Replicator 2. During the print, the printer just stops executing and I am running out of ways to troubleshoot.

After restarting, I can load and extrude filament.

I have replaced the SD card, and even borrowed one from another working replicator, and the freeze still occurs.

Likewise, I've regenerated the x3g file, and that did not work.

The panel does not freeze, I can cancel the print during the freeze.

I've made sure Z pause is off. It tends freezes randomly on the first layer.

In general, it looks as though the print is "in progress" but not making progress (Timer ticks up, % completed does not)

Does anyone have any idea as to what could be causing the problem?

There are a few options. First your board could be overheating etc. That is harder to verify without some overpriced replacements. So to start lets take everything apart (photo and labeling is Strongly recommended). Then simply put it back together. Hopefully it is just a loose connection.

Seems like others have had similar issues: https://www.thingiverse.com/groups/engineering/topic:3849. Their issue was a bit more mechanical than firmware, though. I hope this helps!

You might also want to check the software you're using to slice the file. Sometimes the software doesn't slice the file properly, which causes problems mid-print.


What is this weird support line doing in this print? I am a newbie to 3D printing and ran into a weird infill line on my second 3D printing object on a new Qidi X-Pro machine (which works great). I've included a screenshot of the infill line, which is deliberately printed the full height of the object. I'm thinking this line has been deliberately inserted by the Qidi slicer for some reason, but I have no idea why. Do all slicers generate these kinds of lines? If so, why?

I do not know the Qidi slicer, but if you look closely, you will see this line is thinner than the normal support infill lines. You could try to visualize the G-code in a viewer, usually this can be done in the slicer itself, but online viewers are available. The viewer will not only show the printed lines, but also show moves by the print head (usually in a different color). You can check whether this extra line is actually printed or a move. If it is a move, this extra line is caused by your hotend which is leaking when it moves. You need to properly tune the hotend with respect to the retraction settings and temperature. There are numerous retraction test print objects to find on the internet.

Depending on your slicer settings, some slicers are able to define where each layer starts printing (e.g. random, or start at sharp corner). The fact you see a support structure "printed the full height of the object" tells you that each layer starts at the same position. It is not uncommon in uniform simple parts where each layer starts at the same position (X/Y) as this is instructed by the slicer setting. In Ultimaker Cura such an option is called Z Seam Alignment.

Bottom line, all slicers will do this when your printer is improperly tuned (incorrect settings for e.g. print temperature, retraction, coasting, travel speed). It is up to you to find the correct settings, test print objects help you with that.

Here have a posible solution -> How to remove unwanted filament trails from sharp corners

I think, that can be a combination of z-hopping and combing-mode in the slicer that you use.


Wrong Z-Axis movement in G-Code Alright so I bought a broken UP mini. There was only a defect on the board so I connected the components to a Duet 2 Wifi.
Everything is fully operational and I can manually move all axes correctly using the interface as well as homing them.

The problem is that when I try to slice a model (I am using Slic3r) and upload the G-Code the bed will be raised instead of lowered during printing.

How do I change it so the direction of the Z-Axis goes correctly?

Additional information:

The Z endstop is at the bottom
When homed the Z coordinate is on 0 mm
When placing the bed under the extruder the Z coordinate is 170 mm

You could put the z endstop at the top, and flip the motor connector to make it move the other direction. This should make it home to the top near the nozzle, and then move downward during the print.

Otherwise, you'll have to tweak the firmware configuration and reflash.


Why is my print displacing along the y-axis by 2-3 cm? I am encountering a problem with this ID3 printer using ABS -- at some point during the print the print head displaces on the y-axis by 2-3 centimeters. I cannot pinpoint how or why it is doing this. It has displaced in the positive Y direction and in the negative Y direction on separate runs of the same piece (which is just a poker chip I found on Thingiverse).

Is this a software issue (Simplify3D) or a hardware issue? Can anybody suggest a fix?

See the following photos:

This has happened to me in the past and here are a few things that I determined could have been the cause:

Limit Switch triggered. My coworker was able to repeat the issue by manually triggering a limit switch during the print. Somehow, this seemed to cause the relative axis to shift on his MakerBot Replicator 2.
Skipped steps. It's possible that, if stalled due to excessive load, the stepper motor could skip steps. I have a dual extruder, so if a part curls really bad then the second nozzle gets caught in the print. I'm not sure exactly how this works, but my coworker suggested this as an issue.
USB connection. I had sliced a model and tried printing over USB connection, however each time I attempted the print I encountered the "shift" at the same exact location. However, using the slice, I exported a G-Code file and printed from the machines SD card with no errors.
Slicing Engine bug. This is in correlation to the USB connection issue. I noticed that the issue occurred after updating my slicing engine. My solution in the long term was to re-install the previous version that was stable for me. I was using MakerWare 2.4.2 and reverted back to MakerWare 2.4.1.

If you're printing via USB connection, I'd suggest exporting to G-Code if you're able to print via SD Card until you can find a stable version of software for your machine. This has been the most repeatable solution for me in the past.

In my case the solution was to use Slic3r instead of Cura. Cura has some issues.


slic3r: Can I vary the infill percentage for different heights of my model? How can I vary the infill percentage for different layer heights of my model?

Context: The bottom part of my model needs about 20% infill.  The geometry of the top part of the model (mostly cones of various sizes) prints well with 0% infill and is of course a lot faster to print if I can specify this.

Your question is very similar to Different infill in the same part and Using multiple infill types within one model [duplicate]. The difference is that you specifically ask for Slic3r and a variation in layer height infill percentage.

Actually this answer describes using "helper volumes" in Ultimaker Cura to set different properties for certain parts of the model (UPDATE: that answer now includes also Slic3r instructions), but it appears that this answer is very much applicable to Slic3r also. Please read this posting. Quoting from the reference:

  Finally, I fired Slic3r up and loaded the main part, then clicked on
  Settings... and then hit Load modifier... I loaded the new volume as a
  modifier mesh and I applied 100% solid infill...

Secondly, this answer where 2 different infill percentage sliced models are manually combined at a certain height may also work for you (this is a perfect valid solution for Slic3r, but requires some editing skills).

Basically, although you request for a solution for a slicer other than already described in other questions, boils down to a similar answer, the only difference is the implementation in Slic3r is called differently.

To do this in Slic3r see this reference.

The blog describes the use of a simple volume (the green volume loaded from an STL file). After loading:

  Right-clicking on the main part brought up the object settings menu.
  From there, clicking "Load Modifier" and selecting the previously
  saved model adds it to the part as a modifier.

  The green "+" was selected and "Fill Density" was added to modifier
  list and set to 100%.

This shows that the functionality in Slic3r is very similar to the functionality in Ultimaker Cura.

Let's assume the model is 75mm high; the bottom portion (which needs 20% infill) is 40mm, and the top portion (which needs 0% infill) is 35mm.

Load your model into Slic3r.
Be sure your default fill is 20%.
Right click on the model, and select Settings.
Click "Load Generic".
Select Slab. This represents a cube which is the same X,Y dimensions of your model.
Specify H=35 (the height of the slab) and Initial Z=40 (where the base of slab starts).
This creates a new part for your object.  Select it and click "+" to add a new setting.
Select Infill/Fill Density and set it to 0%.

As a result of this, the bottom part of your model (which is not enclosed in the slab) will print at the default fill setting of 20%, and the top part of your model (which is enclosed in the slab) will print with 0% fill.

You can verify this by slicing and looking at the preview.  You will see the base with your default infill, and the top with no infill.  The slic3r docs mentions several other ways to customize parameters for your model.


First time assemble of Anet A6 printer. Only fan works I bought an Anet A6-L printer (after some research I discovered that this is not a genuine Anet A6) and assembled it. The first time I plugged it in, the fan (fan 2, I believe) is the only thing that turns on. Also, the LCD screen (LCD2004 5 button display) only had 1 cord, and 1 jack for the cord to plug in on the back of the screen, but 2 openings on the motherboard. The fan turns on for around 30 seconds, then turns off. I have the anet A6 printer, with the V1-5 motherboard. I have everything else (fans, motors, hotbed, power) plugged into the right ports. I haven't plugged in the micro SD (TF) card yet, I turned it on to test it.

I am using a modified part that replaces the windpipe/fan duct (white) and redirects the airflow around it and inwards from a ring around the tip, but that is the only modification I have made. I have not messed with the power supply (other than wiring it in). Same with the motherboard. I tested it also without the modification for the fan duct but it still has the same problem.

This definitely sounds like a problem with your wiring if you have a genuine Anet A6, the genuine A6 comes with a 12864 full graphic display. For sure, you are missing 1 flat ribbon cable (see below). Maybe this is causing the LCD not to light up and the SD card not functioning. As the "fan 2" is working, the board is powered by the power supply (this fan is using the constant power feed of the supply of the board). What you are actually describing as a boot sequence is the actual boot sequence of a printer. Once you power the printer, the fan that is cooling the cold end of the extruder should start spinning and keep spinning while the part cooling fan usually spins up but then powers down to standstill. While this is happening, the LCD should come alive and show the boot screen and finally the printer menu. If your screen is not showing any light, this implies that your screen is either broken, not powered or wrongly connected.

You could connect the printer over USB and control the printer from an external program, e.g. Pronterface, OctoPrint, Repetier-host, etc. and see if the printer works (then you know that the display is broken).

From a search on AliExpress I found that there are auto leveling printers sold with the Anet A6 branding that differ from the standard Anet A6 as written in Chinglish:

  Different Auto leveling A6 and Normal A6:

  1.The auto-leveling version uses a proximity sensor to detect the aluminum print bed where the normal version of the printer uses a
  micro-switch to detect the end of travel for the Z-Axis movement
  (vertical limits).

  2.Auto leveling A6-L work with LCD2004 screen, A6 work with LCD12864 screen

The second remark from the quote above suggests that there is a 2004 LCD version that is only used by the Anet A6-L version (probably because they need a free pin for the auto leveling sensor). Such a display only has a single connection socket and needs to be connected to a single socket on the Anet printer board (named "LCD", not "J3")

Note that automatic bed levelling is not magic, and a little more complicated to start with, if you order a printer without an auto bed levelling sensor, you will be able to update to one later. E.g. from here:

  It uses the "LED pin" which is an unused pin on the A8 (using the
  stock 5 button 2004 LCD). That is the third wire counted from below
  (where the red marker is on the cable). I simply spliced the cable and
  cut that wire. This will be the servo signal (yellow).

If you have an Anet A6 adapted for auto levelling with a 2004 display

When the LCD does not light up, this could be caused by incorrect placement of the flat cable, be sure to use the correct socket on the printer board and take care of the orientation. Once you have checked this, and it does not work and you are in the possession of a multimeter, you could measure the voltage over the "VSS" and the "VDD" pin; also look into the voltage over the "VSS" and the "VE" (see pin layout below).
If there is power, but no light, the LCD is probably defective. You could try to hook up a computer to the board using a USB cable and use a program like Pronterface to interface with the printer to see if it works at all, the display is not required for printing (e.i. if you can access the printer over USB).

If you have a genuine Anet A6

It is advised to install an extra flat ribbon cable and check all the wires, please do check for correct polarity and correct installment.

Please do note the the installation of the Anet A6 LCD display (see this movie and the screenshot from this video below) requires 2 flat ribbon cables to function properly.

Sidemark on fan ducts:
Both the stock and most ring type ducts are not aerodynamically designed fan ducts. The stock fan converges too much, this narrowing of the duct causes extra pressure build-up which these fans are not able to handle, so they stall, causing a reduced flow output of the fan. The (semi) circular fan ducts usually also have a design problem. The (semi) circular ones all (but one that I have seen) have the same deficiency that the main passage area does not decrease when the duct loses air through a slot/ejector; this means that the velocity in the main ring decreases after each bleed slot! Note that these fans move air and do not build up a high pressure difference that is large enough to overcome the friction of those designs.

I also ordered an A8, but was sent a A6-L, after doing my homework, I am very happy.  The A6-L is an upgraded A8. It uses same board as A6 but has a A8 display (5 button), that's why people have extra LCD spot. The A6-L is  a better frame (full front), better carriage set up ( horizontal vs vertical, resulting in better weight distribution and allowing for higher builds ).  As far as fans go, the cooling fan only comes on when printing and told to (there is a setting in menu (make sure fan is on, as well as check cura settings for when and how much fan should come on). The Auto leveler that comes with it says to plug into Z limit switch, ( basically it replaces the z-switch all together). Thingaverse has better fan/sensor holders you can print. Remember Google/YouTube is your friend. I found out after lots of searching.
A simple google search answers everything.  The A8 was the 1st printer released by Anet, followed by the A6. Check out links.  Look at pictures and description and comparison. Or just Google it.

A8= \$ cheapest, flimsy frame, off balanced extruder carriage, uses belt to drive Z.
A6= \$\$\$ MOST EXPENSIVE of 3Full frame, better balanced carriage, LCD screen w/ knob, no Z belt.
A6-L= \$\$ Middle Cost, A6 frame, carriage, no Z belt, but A8 screen and buttons

ANET A6-L
https://www.banggood.com/Anet-A6-L5-DIY-3D-Printer-Kit-With-Auto-leveling-220220250mm-Printing-Size-1_75mm-0_4mm-Nozzle-p-1209606.html?cur_warehouse=CN
COMPARISION
https://pevly.com/anet-a8-vs-a6-vs-a3-vs-a2/
AUTO LEVEL

Anet a6 autoleveling


Anyone tried Varathane water-based Wood Stain on Hatchbox Wood PLA? I printed parts for a Harry Potter wand with HatchBox Wood PLA, now I want to apply stain. I intended to try MinWax PolyShades wood stain, then noticed Varathane water-based wood stain is available at my local Rona hardware store. This seems a "healthier" option, maybe not as fussy to apply as PolyShades, anyone had experience with this product?

I ended up using Saman brand water-based wood stain, also from Rona hardware (a brand of Lowe's Canada). The selection of colours for Saman stains was greater than the Varathane stains.

I applied a single coat of colour #117 "Chamois" to the stem portion of the wand, and two coats of colour #120 "Dark Walnut" to the handle. I did not apply a varnish or sealer. The results seem acceptable, given that I Am Not A Carpenter, and this is my first go at printing and finishing wood PLA! Overall, I'm quite happy with the result. I left the PLA mostly unsanded to take advantage of the layers' wood-grain appearance.

Wood stains (as opposed to dyes, paints, etc.) work by having large particles that become lodged in the grain of the wood, yielding a result that varies in intensity with the grain of the wood and thereby brings out its beauty. It's unlikely that they will do what you want, or anything reasonable, on PLA that has wood particles mixed into it. You might be able to find some types of dyes that will work. I've used wood dyes on woods that don't take stain well and have had good results, and if the PLA+wood material consists of a significant amount of wood, it seems plausible that wood dyes might work well on it.


What is the best 3D modeling software for a beginner on a 3D printed mini barrel project? My goal is to 3D print a 5 liter miniature barrel with a side stand, similar to this wooden one on Amazon. I want it to have a removable top so that a boxed wine bladder may be put inside, and there should be a hole on the top as well so that the spigot may stick out and be used. I have no experience with 3D modeling or printing, but I have access to a public 3D printer at my local library. I know you can print parts individually (ex. curved wood-colored sides with staves and holes to interlock and make up the body of the barrel, the metal-colored hoops to go around the barrel). I don't know what software to use, though. I was thinking of starting to learn Blender? Would that be effective for this project?

Your question begins in an inappropriate format for StackExchange, but you've ended it with one more appropriate by asking if Blender would work.
If you are willing to take the time to learn Blender, you are certain to discover that it will do as you require, and much much more. Your referenced model could be created using engineering-type design software such as Fusion 360 or SolidWorks or many of the free packages, but the free-form aspect is more suited to the flexibility of Blender.

2020 UPDATE: Fusion 360 now supports a sculpt feature, which combines organic modeling with the engineering-type for which it is previously known.

Even though Blender is not an engineering-type program, it has internal support for precise modeling. Should you learn to use those features, you get the best of both types of software.
If you construct your model in the software in segments/pieces as you suggest, your result will have greater flexibility at the printing stage, specifically with respect to color and filament choices. Instead of wood-colored sides, you can use wood-simulated PLA filament! Depending on the printer at the library, you could also use filamet, a filament containing 88 percent metal for the hoops.
I use Blender for some aspects of modeling, often importing the STL into Meshmixer to address things I've not yet learned in Blender.
I hope your reference to 5 liter is the original size and that your model will be a miniature of it. A 3d printer with 5 liter capacity would be a wonderful asset at the public library!

To the people saying 123design. I can only say I have been a blender user way before 3D printing was a thing and just cant get around learning 123design. It just feels so limited as it only have a few tools. Yes blender might have a hard learning curve but it does pay off in the future as you wont be limited to 3D printing models and its crucial to make more complex models


Nozzle heats up past the setpoint and increases I made a few successful prints since I got my CR-10 two weeks ago and I didn't run into any major trouble. The printer is new.

Today I set it to "preheat" mode while I was preparing the SD card with the settings being 210°C for the nozzle and 60°C for the bed. When I wanted to start the print I noticed that the temperature showed as "actual temperature" on the printer's screen showed 233°C and it was going up steadily while the "requested" temperature was still 210°C.

Thiking it might be a mis-manipulation on my part I powered it down for a few minutes (I got scared by the high-temp) and then powered it back on. I then immediately requested the print to start. The CR-10 heated up to the proper value, started printing and kept heating the nozzle. I stopped it at 217°C.

I looked for an answer on the internet but all I could find is people having trouble with the nozzle not heating at all ...

This is not an easy one to solve, the firmware of the printer should be keeping the printer at a certain temperature depending on the temperature setting and the current value. If the firmware is not able to keep the temperature at the requested level, but goes beyond that level, that could be considered "strange". As it measures the temperature (and reports it on your display) it must know that it is over the limit and thus should not power the hotend.

In this process there are a few possible candidates for you to look at:

Check for a faulty MOSFET (sort of an electronic switch) on your controller board (is it leaking current to the hotend?).
Check and or update the current settings for the PID values (settings for the control loop of the hotend). The PID values control the overshoot of the temperature. E.g. is this is very large overshoot? When incorrectly configured the temperature can get higher, but normally should never increase to infinity, are you sure it keeps rising? The determination of the new values is called PID tuning. Important commands (that need to be send over a USB connected printer with a 3D printer terminal application like Repetier Host, OctoPrint or Pronterface):

The M503 G-code command shows the current settings (somewhere in the heap of all settings).
The M303 G-code command can determine the values.

Reflash the firmware
Replace the printer controller board

You could replace the thermistor and the heater cartridge (just to be sure, most definitely not the problem, but they are really cheap to replace). The thermistor works as it reports the temperature, and the heater element doesn't get powered by itself.

As suggested below the most likely candidate for your problem is the MOSFET. These are pretty easy to replace (depending on your board) or replaceable by an external MOSFET module (if you happen to have one lying around).

A similar condition occurred in my 3D printer. I solved the same. I checked all my connection and I came to know that I connected the thermistor of the extruder in the wrong port. So just check the connection of your thermistor.

Actually my 3D printer circuit board frequently failed because of over current. I then added a multimeter in series with my power supply and the load, also a voltmeter across the voltage regulator. I then corrected every motor driver DRV8825 to a reference voltage of 0.6 V so that the maximum current supplied to each of the motor will be less than 1 A. All these made my circuit checked ok. Then I uploaded the G-code, but I couldn't print because my extruder gets heated about 280 °C and got reset and suddenly shut down the extruder supply. This continues to happen.

Then I reinstalled the Marlin firmware and I also changed the port of my thermistor. Now my 3D printer is ok and prints nicely. I also faced another problem while I gave the print command - it showed that the extruder and bed had started heating but it actually was not heating. So I reinstalled the firmware again and this fixed it. Now my 3D printer works OK. You just try for these steps:

Check the connection.
Reinstall the firmware.
Try manually preheat the extruder, and just see whether it heats to infinity.

These are my working experience please try for these, I think it will help you. Just don't leave it you will get the solution. Keep on trying.


A single angle, single phone model windshield mount -- a job for a 3D printer? My end goal is getting high quality dash footage from a 6 month road trip I'm going on. From my research, very few dash cams support 4k 30fps filming, and the ones that do overwrite their own footage really quick, so instead of that I'd like to use my iPhone. I have a wide angle lens for it, and I figure I can mount it to my windshield, behind the rear-view mirror.

But here's the problem: there are no windshield phone mounts that allow for the angle I need. They're all designed to point the phone screen at the driver, and the little ball joints that let you set the angle just don't work to point the camera straight ahead. I've tried like 5 different ones, and they all have this problem.

What I need is a solid thing that sticks to my windshield and holds my phone in the correct direction. Once stuck, it never needs to be adjusted. I think I could use 3M strips to stick something to the glass, so the only remaining part of the mystery is this: A piece of plastic the exact right shape to hold my phone and point it at a specific angle.

My question is: Is this a good use case for 3D printing? And if so, how would a complete amateur get started on this?

A few more requirements that I'm not sure if 3D printing can meet:

It would need to withstand heat, as it would be left in the car on hot days in the south.
It can't be too brittle, as speed bumps and dirt roads will knock it around a fair bit, and it has to support a large phone with an added lens.

You'd need to print in a heat resistant material - ASA for example - and design the part for your needs, but this project is certainly feasible and doable with 3D printing. If that isn't enough for you, you could drill a hole to the internal cavity (it's best to have an infill pattern that does not split the internal cavity into several ones. Gyroid is one of these) and fill it with resin to make it even more sturdy.

With the right design, you could also go for SLA/DLP aks resin printing, but I am not well versed in the properties of printed resins but that they have some of the best inter-layer bonds.

If you don't want to get a 3D printer yourself, order the part printed, which usually comes cheaper than an entry-level printer with better quality for a one-off project as you won't have to learn the ins and outs of your printer and how to ensure the quality in the material you choose. Some print services also provide really exotic materials.

Why not try a GoPro camera? They now have 4K, image stabilized camera with all kinds of accessory mounts.

https://shop.gopro.com/cameras/hero7-silver/CHDHC-601-master.html


What is the biggest size of an object that iBox Nano can print? Since iBox Nano is the smallest public-production-available 3d Resin printer (and the cheapest so far), I assume it has a huge size limitation. So far I've only seen pictures of its outputs that are miniature things. I've never tried it nor have I seen it in action in person so I'd like to be sure.

For example, my 3D models are of the size of beads to figurines to a standard sized pencil cup holder.

I want to know in inches or millimeters the dimension (width, length, height) of the biggest possible object the iBox Nano can print.

On their website, I found the following picture, which states a build area of 40 mm x 20 mm x 90 mm (1.57" x 0,79" x 3.54").

From their website I found a comparison between 300 microns down to 50 microns print quality. My answer would be somewhere around this range.


Adding a Bowden extruder to a direct drive setup I currently have a single extruder (direct drive) Tronxy X8.

I am thinking about adding a second extruder, that I would use only occasionally. I really like the characteristics of the direct drive extruder, so I would not want to switch over to dual Bowden. Also adding the weight of a full second direct drive extruder for only occasional use does not seem useful.

Is it possible to use a direct drive extruder as main extruder and a (possibly detachable) bowden extruder as secondary extruder?

Is there anything in particular that I need to watch out for when mixing extruder types?

I'm an amateur and I used dual extruder printers but never built any.

It's probably a good idea, take care about the purge, retractions distances that may vary. On the filament feed side there shouldn't be interference from the different flexibility. Still it maybe good to place one reel on one side and the other on the opposite.

Now the most complex thing is to make both nozzle not interfere. A technique is to rotate by few (like 5°) the dual setup to give few millimeter more to one of the two nozzles. If both heads are at the same height, you'll need to keep them hot, and avoid the passive one to leak. It would be good also (but not mandatory) to have a purge routine.


Extruder motor not running during print job but working after I preheat the extruder and test it I have a Prusa i3 (from FLSun). I have assembled the printer, calibrated it (fairly decently), and have successfully demonstrated extrusion manually. However, when I try to run a print job (the G-code clearly contains E commands), the extruder motor never rotates. Is this a common problem? Any suggestsions for how to resolve/troubleshoot?

I can confirm that the extruder was pre-heated for PLA (up to a generous 220 C).

I load  an STL file into Repetier v.1.0.2, use the built-in slicer (Slic3r) to generate the G-code. I include a sample of that below:

; generated by Slic3r 1.2.9 on 2017-11-08 at 10:54:07

; external perimeters extrusion width = 0.50mm
; perimeters extrusion width = 0.72mm
; infill extrusion width = 0.72mm
; solid infill extrusion width = 0.72mm
; top infill extrusion width = 0.72mm

M107
M104 S200 ; set temperature
G28 ; home all axes
G1 Z5 F5000 ; lift nozzle

M109 S200 ; wait for temperature to be reached
G21 ; set units to millimeters
G90 ; use absolute coordinates
M82 ; use absolute distances for extrusion
G92 E0
G1 Z0.350 F7800.000
G1 E-2.00000 F2400.00000
G92 E0
G1 X76.952 Y76.952 F7800.000
G1 E2.00000 F2400.00000
G1 X78.055 Y75.850 E2.04824 F1800.000
G1 X78.650 Y75.324 E2.07282
G1 X81.121 Y73.387 E2.16997
G1 X81.780 Y72.933 E2.19472
G1 X84.467 Y71.309 E2.29186
G1 X85.167 Y70.940 E2.31635
G1 X88.143 Y69.602 E2.41730

As an update, I can no longer reliably get the extruder motor to run (even when I pre-heat) from the LCD. Sometimes, it works fine, but other times it doesn't seem to. Will confirm whether switching the motor connector to the z-axis to test the motor works when I get home this evening.

I can confirm 1) that there is no tension pulling on the cable connections during the run, 2) the mainboard and motor connector aren't burned, cracked, and the mosfets have heatsinks on them, and 3) the extruder gear is fixed and rotates freely on the motor axis (I tested this by switching it over to the z-axis connection temporarily and confirming rotation).

Here's a photo of my motherboard:

According to all the information:

No reassignment of the extruder in the Gcode
You can extrude if you push the filament by hand
Extruder motor works when switched to Z driver
Z Motor works

I come to the conclusion that some of your electronics or the motor have fried.

What have fried? I tried to make a step by step check:

Switch drivers between E and Z, but plug the motors as usual:

1) Does the extruder extrude?

Yes: Your driver has fried

No:

2) Were you able to move the Z motor?

No: Motherboard And driver has fried

Yes:

3) Plug in the E motor on the Z driver, can you make the E motor turn?

Yes: Motherboard fried

No: Motor fried

HTH and keep us updated if it worked or not!

This should have been a comment: when you say "manual extrusion", do you mean moving filament by hand or using extruder position commands from printer menu? Is extruder motor working at all? You can for example plug it instead of a Z-motor to check.

Suggested points to check:

Motor wire connections, both on extruder and mainboard. Are plugs experiencing tension (being tilted, pulled out) from improperly fixed cables?
Hardware on mainboard next to motor connector. Does it look burned, cracked, lacks heatsinks on mosfets?
Is extruder gear not fixed and rotating freely on extruder motor axis? You will hear sound of working motor, but it will look like it's not pulling the filament.


Nozzle jumps off the bed when using Marlin Mesh Bed Leveling I am using Marlin firmware with a RAMPS board on an Anet A8 printer.

The bed size for the printer is 220 x 220 mm and that is stated in the configuration.h file. When using mesh bed leveling, the nozzle jumps to the first corner on the bed perfectly after setting the x-min to 5.0 but the next two points are off the end of the bed. Here are my settings:

// Travel limits after homing (units are in mm)

 #define X_MIN_POS 5.0
 #define Y_MIN_POS 0.0
 #define Z_MIN_POS 0
 #define X_MAX_POS 220
 #define Y_MAX_POS 220
 #define Z_MAX_POS 240

What could be my issue?

None of the answers address your question to solve it! The only sensible contribution comes from a comment of @TomvanderZanden.

For the sensor to stay within the limits of the bed (considering the offset of the sensor and the size of the hotend carriage) you need to define where the sensor (plus carriage) may go to (to keep the sensor also on the bed, you also need to define the sensor limits). The suggested constants are important in defining the size of the bed and the build volume, but changing them does in fact do not solve your problem. Your problem is that you need to address where the sensor may probe within that specified volume i.e. the sensor probing area.

I use ABL (Auto Bel Leveling) on my Anet A8 using a left-front mounted sensor at position (x = -26 mm; y = -40 mm seen from the nozzle center). In order to have the sensor on the bed area without running into the limits of the carriage, you have to calculate (yourself!) what the dimension of the auto bed leveling area is. This is because the sensor is off set from the nozzle. If the sensor reaches for the whole bed, you need extra space on the axis. To explain this, if your sensor is at the left front, as in my case, the amount of extra space you have left on the right side of the X carriage will determine how far the carriage may go and thus limits the right probe position. If there is no extra space on the carriage (the safest assumption) you just need to add the sensor offset to the maximum bed size (what the nozzle can reach). E.g. my probe X offset is -26 mm. The maximum probe distance is therefore -26 mm + 220 mm = 194 mm.

This means that you need to set the following constants (amongst the settings to enable ABL; the probe and the type of leveling...) in the configuration.h of your Marlin Firmware installation:

#define X_PROBE_OFFSET_FROM_EXTRUDER -26   // X offset: -left  +right  [of the nozzle]
#define Y_PROBE_OFFSET_FROM_EXTRUDER -40   // Y offset: -front +behind [the nozzle]

// Set the boundaries for probing (where the probe can reach).
#define LEFT_PROBE_BED_POSITION (0 + 10)         // 10
#define RIGHT_PROBE_BED_POSITION (220 - 26 - 10) // 184
#define BACK_PROBE_BED_POSITION (220 - 40 - 10)  // 170
#define FRONT_PROBE_BED_POSITION (0 + 10)        // 10

Furthermore the settings you do mention need to be:

// The size of the print bed
#define X_BED_SIZE 220
#define Y_BED_SIZE 220

// Travel limits (mm) after homing, corresponding to endstop positions.
#define X_MIN_POS -33 // Distance from end switch to X = 0 of origin
#define Y_MIN_POS -10 // Distance from end switch to Y = 0 of origin
#define Z_MIN_POS 0
#define X_MAX_POS X_BED_SIZE
#define Y_MAX_POS Y_BED_SIZE
#define Z_MAX_POS 240

The -33 and the -10  define how much the nozzle needs to travel from the endstop position to the print origin! This is not necessary to change when using ABL with a sensor (unless you are using a different print head carriage with a different center of the nozzle). Why these values are -33 and -10 (or values close to this; e.g. for my printer they are -36 and -8) is explained in this answer.

The problem is in the code.
Please use these:

// The size of the print bed
#define X_BED_SIZE 220
#define Y_BED_SIZE 220

// Travel limits (mm) after homing, corresponding to endstop positions.
#define X_MIN_POS 5
#define Y_MIN_POS 0
#define Z_MIN_POS 0
#define X_MAX_POS X_BED_SIZE
#define Y_MAX_POS Y_BED_SIZE
#define Z_MAX_POS 240

Your problem will be ok.


How do I concave an image to create a 3D file for use in a 3D printer? How can I print an embossed image in a concaved shape?

Like a big saucer. I will use this an a mold for a project.

So far I've found lots of software with huge spread of features. It's sort of overwhelming. There is lots of ways to create images into 3D printable objects but to add the extra step and concaving that image is harder to find out.

How would you do it? I'm open to suggestions.

I'm new to 3D printing and would really appreciate the help.

What you describe, sounds like you want to create a lithophane; a pattern etched or engraved on a thin translucent base material (in your case a bowl) that can only be seen clearly when backlit with a light source behind it. Apparently you want to use it for another purpose.

Special software and or scripts that transform the image to the base material exist. An example is e.g. this sphere which becomes a globe when lit from the inside. Recommending a tool for creating such bowl is a little out of scope as these types of questions become outdated very quickly as technology changes or tools cease to exist. With the provided information you should be able to find software that is able to provide what you want to do.

You may want to look up https://3dp.rocks/lithophane/ it lets you do things like that


How can I set the 1st layer after a raft in Slic3r to print at 1st layer speed When you add a raft in Slic3r, the first layer of the raft prints at the first layer speed.  After the raft is finished, the first layer of the print prints at the standard speed.  How can I make the first layer of the actual print slow down to the first layer speed?

This is still work in progress, and here is what I have so far, but first:

A useful alternative for similar problems:

A problem very similar to this would be to use different settings for different parts of a model in Slic3r. For most settings, this can be achieved through modifier meshes.

Post processing scripts:

As far as I know, Slic3r does not give you the option of setting the speed of the first layer after a raft directly, but they do allow you to run post processing scripts; that is, to automatically run a set of operations - programmed by you - on the g-code output.

Although far from trivial, you can in theory make a program that runs through the output g-code, adjusts the settings to your preference, and then saves it again at the target destination.

Tuning overall printer speed through g-code:

As it turns out, there is a simple g-code command that sets the overall speed of your printer's operation:

M220 S[some number]     ; see the link above for compatible firmware

A newsletter from Reprapwold explains that:

  For example M220 S50 will reduce the speed to 50%
  of the original sliced G-code. If you want to hurry your print to the finish in time
  for dinner, use M220 S200, to print twice as fast (200%)

In other words, just like some printers allow you the change speed mid-print, you can use the M220 command to override the current speed used, either through a user interface such as PrintRun, or by fiddling with the original g-code itself.

Manipulating the g-code output to adjust speed settings:

The easiest way to achieve our goal would be to manually manipulate the output g-code file through a text editor, and insert our M220 command in appropriate places:

Set M220 S50 just before the first perimeter layer (after the raft's interface layer), to slow down the first layer of the actual model.
Set M220 S100 sometime after the first perimeter layer, to resume the normal speed settings.

In order to do this, though, we need to be able to distinguish these two points in the g-code output.

Distinguishing insertion points:

Slic3r offers a setting under Print Settings -> Output options -> Verbose G-code that - when enabled - inserts written comments all throughout the g-code files generated.

If one inspects a g-code file outputted for a model with raft, one will find the comment:

; move to first perimeter point      <- lets call this A

and

; move to next layer (x)             <- lets call this B

littered several places throughout the gcode.

It is under my impression that the first occurrence of comment A happens right after the raft is finished, and before the actual model is being printed, while the first occurrence of comment B succeeding comment A can be used to set the speed back to normal.

It should be noted, however, that the comments in the output g-code does not seem fully consistent, and I would therefore not recommend anyone to automate this logic into a script without possibly finding other, more reliable breakpoints, and thoroughly verify these through several different models.

I have not looked into the details of writing an automatic script for this task as of yet.

You shouldn't need to. The purpose of a slower first layer is to help with need adhesion. With a raft the first layer of the model is printing on the raft so it can go at regular speeds.


Open Source 3D scanning I am trying to make a structured light 3D scanner using single camera, light projector and a turntable.

After days on Google I did not find any reliable open source project which I can get to work.  SLStudio really seemed a good choice but did not compile properly.

I was wondering if anyone knows a good open source which they have used with the same kind of setup? Any help would be really appreciated. I am blocked here.

I did find only one 3d scanner which uses structured light. There is many projects using a laser diode. And these systems are completely opensource.

Structured Light

Structured Light 3D Scanning by kylemcdonald

http://www.instructables.com/id/Structured-Light-3D-Scanning/?ALLSTEPS

Laser diode

Sardauscan

http://www.instructables.com/id/Build-a-30-laser/?ALLSTEPS
https://github.com/Sardau/Sardauscan
http://www.thingiverse.com/thing:702470

ATLAS 3D Scanner

http://www.freelss.org
http://www.thingiverse.com/thing:1280901
https://www.kickstarter.com/projects/1545315380/atlas-3d-the-3d-scanner-you-print-and-build-yourse/posts/1475722

Ciclop

http://diwo.bq.com/en/tag/ciclop/
https://github.com/bqlabs/ciclop

3D(ollar) Scanner

https://hackaday.io/project/2021-3dollar-scanner
http://www.instructables.com/id/Lets-cook-3D-scanner-based-on-Arduino-and-Proces/?ALLSTEPS

"Super Make Something" Tutorial On How To Build a Simple 3D Scanner

https://www.youtube.com/watch?v=-qeD2__yK4c
http://www.thingiverse.com/thing:1413891
http://diy3dprinting.blogspot.de/2016/04/super-make-something-tutorial-on-how-to.html

Different method

$15 3D scanner consists of a tub of milk and a smartphone

Interesting idea of using milk and phone.

http://www.instructables.com/id/GotMesh-the-Most-Cheap-and-Simplistic-3D-Scanner/
http://www.3ders.org/articles/20160423-this-3d-scanner-consists-of-a-tub-of-milk-and-a-smartphone.html

BQ Ciclop 3D Scanner

Scan Volume: Bigger than 5 cm x 5 cm and smaller than 20 cm x 20 cm
Scanning Precision: 0.5 mm

All the necessary parts for Ciclop are included in this DIY kit, which comes unassembled.
This Ciclop 3D Scanner Parts List:

1 x Plastic parts( 1 set with 11 pcs)
1 x Arduino Uno R3 with USB cable
1 x ZUM Scan Shield
1 x A4988 Stepper Driver
1 x C270 HD camera
1 x Nema17 stepper motor
2 x Laser
1 x Power supply adapter
1 x 16014 ball bearing
1 x M8 threaded rod (9 pcs)
2 x Acrylic panel
1 x 8mm spiral wrapping band
1 x Set of screw and nuts


Are there biocompatible materials available to the general public? I am currently working on parts for a custom prosthesis.

My main concern at the moment is to find biocompatible materials that can be 3D printed from a UP or a Reprap.
The piece would need to be in contact with the skin for extended periods of time, probably around 17 hours a day on average.

The main concerns I have are:

Skin reactions caused by prolonged contact
Skin reactions and bruising caused by friction
Degradation of the materials due to prolonged exposure to skin secretions and sweat
Risks of toxicity in the compounds generated by the aforementioned material degradation

Which materials can you recommend?

Any extensive data (from testing) would be greatly appreciated.

There are printers designed for medical use, and the manufacturers supply them with varying levels of certification and testing, however I've not seen a filament manufacturer certify their material as bio-compatible separate from the printer. The printing process changes the material slightly in the best case (and significantly with poor temperature control or badly set parameters), so even if bio-compatible filament were found, the resulting product might not achieve the same level of bio-compatibility.

If your intent is to use hobbyist level machine for medical purposes, you might simply want to use an interface, such as a sock or a molded/cast polymer that you know to be bio-compatible between the printed part and the skin.

If you want to know something about what you are questioning, it is interesting to you to read http://e-nable.org/resources/prosthetics-students-consultation/

That's a link with complementary information how to print 3D as a volunteer.

I know that is not enough information about products, but I believe Nylon is the best recommend because it is what generally printers are using, though.

This website supports information with Dr. Chang by the e-mail eagle01@rocketmail.com

but there insnt information about the components used in the prosthetics, but I know that Nylon is the best suited to it nowadays.

If you prefer there is a site with makers loging information about PETG:
https://www.matterhackers.com/news/how-to-succeed-when-printing-with-petg-filament


How to transport a 3D printer? Dismount needed? I need to transport my FDM 3D Printer because I am moving.

What are the precautions that one should take? Should I dismount the motors and axes? I would definitively unplug the electronics as far as reasonable and fix the motors to the frame so they don't slide during transport. Should I have a housing to avoid dust and other mechanical issues?

Yes, fix the motors and any other loose/movable parts. Remove the bowden tube if it's there, and any other parts that are sticking out. Put the whole thing in a a bag to protect from dust, and put the bag in a box to protect it from getting beat up. Remember to calibrate it when you're ready to set it up again.

You just need to take basic security actions. like fixing all movable parts simple as that


Why the Ender 5 Pro can't remember the axis position or cant move back to home anymore? I am completely new to 3D Printing. I got my first printer a Creality Ender 5 Pro yesterday.
My problem
I did shutdown the printer without the axis being in home position (X: 0, Y: 0, Z: 320 instead of X: 0, Y: 0, Z: 0). I thought this should be no problem but after turning the printer on again the info screen showed the axis as 0, 0, 0 again...
So I can't move the Z axis up again because the printer thinks its already at 0.
NOTE: On the Ender 5 the bed is lowering for the value of the Z so 320 is the lowest and 0 the highest. The motor works because it tries to go down further if i increase Z position but I am scared of damaging the motor because it can't move further but it tries to (judging by that weird sound).
My question
Is this a normal behavior that the printer axis cant remember its position? Because I think as I built the printer the axis were also not at the 0, 0, 0 position and on the first start they moved back without any problems.
Has someone any ideas how to solve this? Or is this a broken printer?
PS: I could replicate this behavior on X and Y as well (moving them with prepare->move axis and then shutdown the printer) but here for I can easily disable the motors and move them manually back to 0, 0 which isn't the case for the Z Axis.
I hope I could explain that understandably.

Once you pull the plug or disable power to the stepper motors, the printer forgets its location. That is perfectly normal and exactly how it is supposed to work.
The printer knows where the printer volume is once you have "homed" the printer. Homing is done prior to printing with G-code G28 which should be present in your start G-code script of your slicer. Once homed, the offsets from the endstops determine where the origin of the printer is and the maximum dimensions determine the build volume.
After you switched on the printer, the printer doesn't know where the origin is and movement is limited. E.g. when the following constant is defined: #define NO_MOTION_BEFORE_HOMING no movement at all is possible before the printer is homed, this can help prevent destroying the printer.

Slightly unscrew the motor. Manually rig the Z-axis above its lowest point. Rescrew the motor back into place tightly. Then auto home it.


Trouble printing Poppy Robot with SpiderBot For a university project, my partner and I need to print the robot Poppy. This is an open source robotic project, poppy-project.org.

We are printing it with a double extruder SpiderBot with PLA and HIPS as support material. Our principal issue is the weakness of the pieces we print.

It prevents us from removing the support material without damaging the piece. We don't have the chemicals to dissolve HIPS.

Have you some advice to make the pieces stronger, or a more gentle method to remove the HIPS?

Thanks for the replies

Having a bit more experience since my comment post above, I can offer up a possible solution. If your printer is able to print ABS, it works great with HIPS as support material. I've been printing boatloads of ABS models. When support is needed, the HIPS supports will bond reasonably well to the ABS, but when cooled, flick off with a sharp pointed instrument such as a razor knife point.

As an additional reference, a good bond to the print bed is required for both ABS and HIPS and if your slicer allows support density adjustment, increase the support in that manner. My slicer (Simplify3D) would print an accordian type of support unless instructed otherwise. I set up for alternating 45° patterns making a denser but also more vertically rigid structure.

If you cannot print ABS, PLA and PVA as Ogre55 suggests is about your only option. I see from the 'net that the SpiderBot Pro supports ABS, which implies the basic version might not have a heated bed.

Why not try using PVA(Polyvinyl alcohol) for support material.

I use it for my support material with PLA, and it dissolves in water.

here is a link to some on Amazon.
https://smile.amazon.com/eSUN-1-75mm-filament-natural-0-5kg/dp/B00MVIQASU/ref=sr_1_3?s=industrial&ie=UTF8&qid=1508539512&sr=1-3&keywords=PVA


Bed design for magnetic easy release when printing PLA I print on a glass bed covered with BuildTak. Prints stick well, release is difficult. They sell a mod, self adhesive magnetic sheet that holds a steel plate which in turn you put the BuildTak on making it easier to get your prints off by twisting the flexible steel as opposed to chiseling your print off a glass plate while attempting to not peel chunks of the expensive Buildtak off.

Magnetic sheets have different strengths proportional to thickness in milimeters. I can get 0.03 mm locally which provides 85 lbs pull per sqft. and was wondering if this might work. It's hard to find the stronger pulls, 0.045 mm and 0.06 mm which can pull 115 and 145 lbs respectively.

I'd prefer cut my own new bed sandwich rather than pay 90 bucks for one.

Has anyone made a bed using adhesive magnetic sheet>
What thickness magnetic sheet has worked for you?
What thickness steel are you using?

Assume it has to flex easily to twist the part of and also flexible enough for the magnet to pull it flat.

With respect to the comment by tbm0115:

  I don't think you need that much magnetic pull for this application. Adhering basic coin magnets to a material in a large array should secure the material appropriately for a desktop printer.

I see where you are going with coin magnets. Have you tried this? In the original Makerbot Cupcake this is how it was done though with larger build surfaces you get warp on metal plates. Most metal sheet comes from the plant on a roll. Though your metal looks nice and flat, temperature changes will cause it to warp and as you know with SLA printers, a changing bed can cause a failure. This happened on the original Makerbot replicator 1st release followed by using a machined plate as a replacement.

Follow up:

I used the 6mil magnet, cut a sheet of thin steel, (about .5mm) to fit, added a layer of Buildtak and now it's much easier to remove prints, build surface is very flat. I assume you could deform the metal beyond the magnet's ability to flatten it but it works quite well. The metal was cut with sheet metal snips, risky as they can bend the sheet. Probably better done with a saw though.

Try using buildtak flex. https://www.buildtak.com/product/flexplate/

or cheaper alternatives:
http://www.printinz.com/printinz-plate-3d-printer-bed-upgrade/


How do I give 3D-printed parts in PLA a shiny smooth finish? The surfaces of my printed parts using PLA plastic look rough and uneven.

Would changing filament to a better one make any difference?

If not, what kind of methods can I use to achieve a smoother finish for my for 3D-printed objects?

PLA parts can be finished with a coat of epoxy like XTC-3D from Smooth-On. This will smooth out the part and give it a pretty nice shine.

I've also had a fair amount of success sanding prints, giving them a coat of automotive filler primer, and using glossy spray paint.

You can also get great results with an acetone vapor finish if you're willing to switch to ABS. Though that will require a heated bed and can be a bit more finicky to work with than PLA.

I suggest using XTC-3D since your prints are small also you can add some UVO pigments in. It's difficult to use in large prints because has small working time. Anyway here is a print I did for a friend:

This now dead link shows more images and say how it is done.


How to calculate the strength of a printed object? If I'm working with standard PLA, and I want to print a box that I can stand on without any risk of it breaking, is there any good way to calculate the appropriate print settings?

I know that structural strength comes from the infill.  Knowing this, and knowing the dimensions of the box, the weight of my body, the surface area of my shoes, and the material I'm working with, is there any good way to determine the minimum infill percentage I'd want to use in order to safely bear my weight?

Strictly speaking, it is difficult to do calculations on these materials, but not impossible (I've heard about a few commercial analysis tools that do that). The FDM process (Fused Deposition Modeling) creates a product based of fused slices of material causing an anisotropic material (this means that the properties of the material are different in different dimensions). Basically, your product will be quite strong and similar in the X and Y directions, but fragile in the Z direction (layering direction). You can imagine that every layer may be a seed for cracks to grow when you're pulling at the part.

When applying a compression load on a product like in your example, the walls need to be strong enough to hold the pressure (not all of the load as, based on the type of infill, the infill also can/should take part of the load!) and need to be of sufficiently high percentage, not only to take part of the load, but also support the walls to prevent buckling. I remember that stress calculations for buckling are difficult and require FEA (Finite Element Analysis) for more complex objects other than bars or beams.

I think it is difficult to determine or calculate the infill percentage based on the compression load beforehand as you do not know the exact material properties and the buckling behavior. You do know that a 100% infill will give you enough strength and support, you could try to print at a lower infill, e.g. 75%, and test if that works for you.

A fast way to do this is by using SolidWorks.

You can draw the box in it and run a simulation test with the max load expected.

Here is a link on how to make dynamic load simulations work in SolidWorks, How to apply dynamic load in solidworks simulation ?

The catch in the process is that SolidWorks takes cubes and most objects as complete solids, i.e. 100% infill in 3D printer terms.

You would have to actually design your infill pattern into the cube so as to get the best and most accurate result.


Is Tetrahydrofuran viable for dissolving PLA and sticking PLA objects together? According to Wikipedia, Tetrahydrofuran dissolves PLA. It also apparently dissolves PET.

  THF is considered a relatively nontoxic solvent, with the median lethal dose (LD50) comparable to that for acetone.

Wikipedia further states that it's not particularly dangerous provided you keep it away from air circulation, so that it does not form peroxides.

  One danger posed by THF follows from its tendency to form highly explosive peroxides on storage in air.

So well, this seems acceptable compared to other possible solvents which are all ridiculously dangerous. The question at hand is now of practical nature:

Is Tetrahudrofuran actually viable replacement for acetone, which only works with ABS?

I am asking because the fact that it does dissolve PLA does not really at all mean that it will work well. It could damage PLA structure, be more toxic than wikipedia says or not dry well.

According to Shuichi Sato, Daiki Gondo, Takayuki Wada, Shinji Kanehashi & Kazukiyo Nagai: Effects of various liquid organic solvents on solvent‐induced crystallization of amorphous poly(lactic acid) film in Journal of Applied Polymer Science, Volume 129 Issue 3 (2013), p1607-1617source, Tetrahydrofuran is classified as a solvent for PLA. The specific entry on page 1608:
Group  Solvent          Solvent type    dd   dp   dh   dt   Result
Ether  Tetrahydrofuran  Polar aprotic  16.8  5.7  8   19.4  soluble

The values dd dp dh and dt are explained on page 1607:

The effects of 60 liquid organic solvents on PLA are systematically
investigated using the Hansen solubility parameter (HSP). The HSP
is one of the digitizing methods for analyzing the interaction
between polymer materials and organic solvents. In HSP analysis,
all solvents have three parameters: energy from dispersion bonds
between molecules (dd), dipolar intermolecular force between molecules
(dp), and the hydrogen bonds between molecules (dh). All solvents
were characterized by a point in a three-dimensional structure
at which dd, dp, and dh are plotted on three mutually perpendicular
axes. Generally, if the HSP values of the various organic solvents
are near that of the given polymer, the solvent is considered compatible
with the polymer material.

The factor dt is the total Hansen solubility parameter - the bigger this is, the better it is a solvent.
19.4 is a rather good solvent but extremely explosive: in air 20000 ppm (2%) are explosive and thus the allowable concentration in an area is 2000 ppmsource
Alternatives
A similar potent solvent would be Benzene (dt = 18.6) which more easily available and less explosive, but more deadly (10000-20000 ppm fumes) and has an allowable concentration of 500 ppmsource
Ethyl-acetate is also a solvent (dt = 18.2) and more available. It is explosive at an equal concentration as Tetrahydrofuransource, but it has just about half of its vapor pressure (73 mmHgsource  vs. 132 mmHgsource), so can be stored more safely, and is less aggressive on the body. It is sometimes used to Smooth PLA via vapor chambersource, and only comes at a price tag of ca. 90 €/l for the pure stuff and also is used in some nail polish removers, put into a safe mix.
Acetone is classified as a better solvent (dt = 20.1), and it is known to act as a glue and to soften PLA with some exposure time, but from experience, it can't smooth it. It is available most easy (nail polish remover and in the home depot), and is the least deadly option.
Propylene-1,2-carbonate is classed as solvent and a far better at it with dt = 27.2. It has been used as an alternative to Ethyl-Acetatesource and its MSDS is rather gentlesource. It comes at a price tag of 130 €/l for the chemical-grade liquid.
Conclusion
Tetrahydrofuran is not a viable replacement due to its explosive properties. It is not an improvement above Benzene, which at least can be stored safely.
Using Acetone as a benchmark, Tetrahydrofuran should not smooth the surface in a vapor chamber, as it is a worse solvent than Acetone. It should also take longer to soften and dissolve objects than Acetone, but a heated bath or coating the surface with it could help to generate the needed exposure times.
However, its comparable ethyl-acetate has been claimed to be used as a cleaning, vapor smoothing, and brush on surface smoothing agent successfully and can be used better by helping the solubility via heating, which can be done much safer with ethyl-acetate than THF. In a proper chemical mix, its storage problem can be solved too.
A better alternative is propylene-1,2-carbonate, which is a better solvent, and much less dangerous.
tl;dr: No, Tetrahydrofuran is not able to dissolve PLA in a reasonable time1 without heat activation and it has worse characteristics than Acetone. It could arguably be used to weld parts, but Dichloromethane would be more effective.

1 - Sato, Gondo et al. in the aforementioned paper: Solubility tests were performed for 24 h at 35+-1 °C. which means we have a prolonged exposure of a thin film to a huge amount of solvent. how thin a film? Very thin: The PLA films
were prepared by casting 2 wt % dichloromethane solution onto a
flat-bottomed glass Petri dish in a glass bell-type vessel and by drying
under atmospheric pressure at room temperature. Each solvent
was allowed to evaporate for 48 h. The dried PLA films were then
thermally treated under a vacuum for 48 h at 70 °C to eliminate
the residual solvent and to obtain amorphous PLA films. Afterwards,
the thermally treated PLA films were cooled at room temperature
under atmospheric pressure.

From what I have read, THF is not super effective, it seems that Dichloromethane or DCM is actually a better solvent.  Unfortunately I have no personal experience with either.

It is rather nasty though, as the LD50 is just 0.5 to 5 g/kg[1][2].


Is it a good idea to include thermal fuses in a DIY 3D printer design? 3D printing should be relatively safe, however, the inherent nature of 3D printers, with all of the heated parts, constitutes a fire risk. A well designed 3D printer should be designed to be as safe as possible, especially one used in the home... Yes, the recommendation is, when printing, to watch the 3D printer at all times and never leave a print unattended. However, with some print times lasting hours and days, this is not always feasible, nor practical. So, some inbuilt safety features should be included, to at least mitigate the risk of fire, to some extent.

Is the use of thermal fuses1,2 a good idea3?
Would you use more than one?
Where should one place a thermal fuse? Next to a particular component, or free standing, in the air, to get an average, rather than highly localised temperature?
Against which components should a thermal fuse be placed? There are a number of places to choose from, such as next to:

The hotend?
The heated bed?
The extruder?
Each of the stepper motors?
The power supply?
The RAMPS stepper motor drivers?

Of lesser import, which type should one use4, radial or axial?

Has anyone added thermal fuses to their 3D printers? Or has anyone examined where the thermal fuses are placed in commercial 3D printer designs, if used at all?

Background

I have recently found myself having to repair rice cookers and fans in Thailand. In those, it is very often the thermal fuse (axial thermal fuses for the rice cookers and the square "radial" types for fans) that requires replacing, as they have blown before the device got hot enough to start a fire. This got me thinking about their use in a 3D printer.

Footnotes

1 We are not talking about the standard, replaceable, thermo-fuse,or fuse, which blow upon a current surge, short-circuit, etc. These are thermal fuses that contain metal connector within them that melts (permanently) at a specific temperature (typically ~135°C), thereby breaking the circuit.

2 Nor am I referring to resettable fuses (AKA PPTC, multifuse, polyfuse or polyswitch)

3 Would a thermal fuse be preferable to thermal cut offs, in the case of fire?

4 The thermal fuses used in rice cookers are the axial type, and in the motors of fans are the radial type.

Whether you should use a thermal fuse or not depends on what other safety measures you've taken. You can't look at the safety features of a printer in isolation, you need to look at what other measures are in place.

The main fire hazard in printers is unfortunately (still) the fact that some manufacturers use underrated connectors on their boards, and that some users put bare wires in screw terminals or use inadequate torque when tightening terminals. As the wire works itself loose, it starts arcing and burning the connector. A thermal fuse does not help in this situation (unless you place thermal fuses near all of the connectors, which is impractical). Instead:

Properly tighten screw terminals, check them, and consider using proper wire termination (crimp lugs).
Use strain relief on wires. Make sure wires don't rub against anything, and guide them so they do not bend in a tight radius. Since the extruder (or print bed) is constantly moving, those wires are subject to fatigue.
Make sure connectors (especially those for the heated bed) are rated for the current running through them, and solder wires directly to the board if necessary.

Using a regular fuse may protect against wires shorting against each other should their insulation be damaged. Fuses are usually already integrated into the main board.

Most firmwares include some variant of thermal runaway protection, a feature that monitors the heaters and shuts the printer down if it notices something gone wrong. This protects against:

The thermistor coming loose/reading incorrect values/etc...

but not against:

Bugs in the firmware itself
Failure of the MOSFET

Most printers use MOSFETs to switch power to the heating element. Unfortunately, when MOSFETs fail, they usually fail closed (i.e. conducting). This means that, even if the firmware detects something has gone wrong, it won't be able to do anything about it. Solid State Relays (TRIACs) can fail in the same way.

To protect against this, mounting a thermal fuse (or resettable bimetallic switch*) on the heated bed may be a good idea. However, thermal fuses with ratings up to the operating temperature of a hotend do not appear to be available so this is not an option.

Attaching the fuse physically to the part it is monitoring is the most reliable, but for instance with the hotend (if you wanted to protect it all) this might not be feasible to the high temperatures involved so you'd have to settle with monitoring the air temperature close by.

Also consider thermal balancing. A thermal fuse is unnecessary if the component can not overheat to begin with. For instance, most MK2 heated beds struggle getting up to even 100C, so even with a shorted MOSFET they present no danger. However, if you have a powerful high wattage (mains-powered) heated bed, you should definitely install thermal protection.

E3D supplies their hot ends with 25W, 30W and 40W heaters. The 25W heater is the safer choice, since it limits the maximum temperature the hot end can get to, while with the 40W heater you can reach higher temperatures (and reach them faster). Barring a very unlikely scenario in which simultaneously (1) the power supply fails and starts supplying excessive voltage and (2) the MOSFET and/or firmware fails, a heater that is sized appropriately to the load it is driving can never pose any danger.

I don't think it's common to install thermal fuses on steppers, stepper drives or the power supply (which should have its own protection). For every possible location to place a thermal fuse, you can probably think up a failure mode in which that fuse would save the day, but at a certain point it just becomes overkill. The stepper drivers would likely burn out well before the steppers would get hot enough to pose a threat, and overheating of the stepper driver would probably (violently) destroy it but afterwards it should not pose any threat.

Axial v.s. radial does not matter, just use whatever is convenient for your situation.

* Note that some bimetallic switches short one of the leads to the (metal)
 case when tripped, which poses a danger, especially with mains-powered heaters.

I haven't found a good way to flood the entire machine, including the electronics, with CO2 gas or another extinguisher when the alarm sounds.

A servo or some other actuator attached to a fire extinguisher, and then attach it to a thermocouple or some other sensor.  Maybe a knockoff Arduino, which the small ones are 2 bucks a pop.  Since Arduinos are open source, you aren't pirating anything, so clear conscience.


Weird Movement and not homing https://photos.app.goo.gl/O6yPf3sDeV1yhS0C2

I tried to illustrate my problem in the videos above, two of them show the weird movement and the other shows me clicking on the home button repeatedly.

Some Info:

Marlin 1.1.8 or 2.0.0 (same problem in both)
Robotdyn RAMPS 1.4
0.9 angle stepper motors
DRV8825 drivers configured at 0.8V Vref
Anet A2 Plus stock for all the rest

As far as I can see on the attached videos your homing movement is reversed.
as per Marlin, the homing for X shall move towards the left side and for Y to the back of the printer.

That could occur when: cable connectors to stepper motors are reversed, or the motor is assembled the other way (you can set reverse direction in Marlin)

The other issue is steps/mm calibration need to be done see source below.

The high pitch in the video could also point that the drv8825 is shutting down the movement as it is overloaded.

please also check that for vref

  Configuring Vref In order to measure Vref you first need to turn on
  your printer as you normally would. If you only connecct using USB,
  but not external power, you get a wrong reading.

  You need to turn on your multimeter and set it at 2v. Put the red one
  on the potentiometer and the Black one on the Gnd pin. Both are marked
  on the images here.

  Before starting this I read they come with a very high vref setting,
  and it is recommended to start around 0.5v Vref. After measuring mine,
  I can confirm they come with a very high initial setting. Mine both
  came at 1,65v or so! - Yours might be different, which just underlines
  the importance of doing this.

  Contrary to normal potentiometer usage, the ones on most copies/clones
  of DRV8825 are lowered by turning clock-wise, so that is what we will
  do, to we hit 0,5v on each. - A quarter of a full turn lowered it to
  0,7v, - after that it goes very, very rapidly down, so aim for the
  quarter of a turn + a tiny tad more. If you buy your DRV8825 directly
  from pololu.com the Potentiometer are dialed up by turning it
  clock-wise:

source

The problem was the logic of the endstops that were reversed


What is the least expensive 3D printer? What is the least expensive 3D printer available today? I am looking for something suitable for general use in a home office.

Depends on your definition of "available" and your definition of "suitable for general use."

The cheapest 3D printers are mostly Kickstarter promises that take a year or more to ship, if they ever do. For example, the Peachy 3D printer Kickstarter just imploded and failed. There have been many other failed low-cost 3D printer crowdfunding campaigns. Another low cost Kickstarter printer, the 101Hero, is ongoing now (May 2016), but most competent observers I've talked to don't believe it will succeed at delivering working printers to all backers at that price point. If they do deliver, it will be painfully low-cost components and the printer will not perform well or last long. Stay away from crowdfunding campaigns for your first printer. At best, you get a beta product with lots of kinks to work out. At worst, you get nothing and lose your money.

For actual products you can purchase today, there's a wide spectrum of quality/cost tradeoffs.

Under \$200 there's nothing credible. The Tiko (\$179) might deliver, but post-Kickstarter units are widely expected to cost more.
Around \$200-300 you get into low-quality Prusa i3 kits from China. These aren't a great value -- most people end up spending another few hundred dollars on upgrades to get them working reliably and with high quality.
Around \$300-400 you can get an ok 3D printer, often with "chipped" proprietary filament so the vendor can make high profits on locked-in consumables. ("Razors and blades" model.) For example, the XYZPrinting Da Vinci Jr is \$350 but locks you into high-cost chipped filament. The Wanhao Duplicator i3 is currently a community favorite for value-for-money at \$399. The Printrbot Play is much higher quality/reliability but much smaller at the same price.
If you get up around \$600, a big range of decent printers opens up. But this is no longer the "least expensive" option, so I won't get into it.

If you want to tinker, the Duplicator i3 is a good choice. If you want a machine that just prints, the Play is a good choice. There are other printers and cheaper printers, but most of what you'll find below $400 is going to end up causing pain unless your goal is simply to tinker with printer troubleshooting and upgrades.

You can get an A8 3D printer on Gearbest at 149$, It's a version of an i3, with easy assemble and pre configured, and it have a suprising good quality.

I thinks is the best price/quality that you can find at the moment. It prints with a good quality by default and you can upgrade it if you need it without spending hundreds of dollars.

http://www.gearbest.com/3d-printers-3d-printer-kits/pp_337314.html


Choice of lead for lead screw This video brought to my attention the 8 mm lead of the Ender 3's Z axis screw, which seems like an exceedingly bad choice from a standpoint of accuracy with respect to common grid alignments in the Z direction. In particular, with the stepper having 200 full steps per rotation, the 8 mm lead consumes all the powers of two out of 200, leaving 25 full steps per mm - and 25ths of a mm are not a typical unit that layer heights/feature heights are going to be in. It seems like a 5 mm lead would be ideal, giving you 40 steps per mm, evenly divisible by 3 powers of 2 and one power of 5, for exact tenths and exact eights.

Is there a motivation behind the choice of 8 mm lead? Is this common for other printers, and are there printers that use a 5 mm lead, or 5 mm replacements that work well?

I've not seen trapezoid lead screws with 5 mm lead, you can get 5 mm lead ball screws though.

On one printer I use 4 mm lead screws to get native 0.02 mm resolution (so 5 full steps for 0.1 mm, 10 for 0.2 mm, etc.). I also geared down 8 mm lead screws with a 2:1 ratio (e.g. to use a single Z-stepper driving a belt that drives 2 lead screws), works fine.

You are delving into the darker recesses of 3D printing here!

ACME threads, anti-backlash nuts, ball-screws, etc. will ALL follow...

The simple answer is that the Z-axis screw on all the cheaper 3D printers are pure crap! They use 8mm With triangular threads because it they are cheap and most software works with it.

The first major upgrade most folks make to a printer (after the print bed surface) is to replace the Z-axis screw and nut. Many are poorly mounted and/or warped, resulting in Z-axis wobble.  Most suffer major backlash - offset only by the fact that most printing only ever goes upwards...

The ideal upgrade would be to replace the rod and nut with a good quality ball-screw assembly that is properly mounted. But, if you do change the pitch, make sure you can alter the software to account for it...

That said, if your prints are good, enjoy, and don’t sweat the details!


Cura slicer, enforce Z move before layer change I am slicing with Cura and Slic3r and one important thing that I recently took my attention is that cura positions head in start point of the new layer and then lifts the nozzle. That caused my few printouts to fall as they collided with the nozzle.

Slic3r behavior is different: it raises the nozzle in last printed point and then moves to a new layer starting point (which for me is more obvious)

Is there a way to instruct Cura to lift nozzle before it goes to the starting point of a new layer? excluding Z-hops.

To lift the head to prevent the nozzle to tip over your print you could use an option called Z hop in Cura. Just enter `hop' in the search box on the right side to make those options magically appear (in a recent version of Cura, e.g. version 3.x.x).

Other than Z hop there is no default action, or series of commands, per layer to be specified before the start of the layer. There are 2 other ways to circumvent this:

The first is saving you G-code to file and open the file in an advanced text editor (e.g. Notepad++). With a (recorded) macro you can find the words ;LAYER:, which are inserted by Cura before each layer starts, and insert a pre-copied list of commands that set the movement in relative mode, move Z up 2 mm, set into absolute mode again. When the next layer starts the extruder goes to the layer start from a 2 mm rise.
Write a plugin for Cura to post-process (C:\Program Files\Ultimaker Cura x.x\plugins\PostProcessingPlugin\scripts) the G-code file to inject the code to Z hop before the start of every layer, or a plugin that adds a new option and/or category to the slicer settings sidebar of the GUI.

OK, after going via all the options I found that CURA has a combing mode which reduces retraction and offers another option which is Avoid Printed Parts When Traveling.

That solves my problem.


Can I mix ABS and PLA when recycling filament? I'm thinking of recycling some filament from a couple of recently failed prints. I can reuse them in the future for basic prototypes, so I'm not concerned with whatever weird mixture of colors come out (they are of a few different colors).

The thing is, I have both PLA and ABS, in small quantities. I originally intended to simply use each one separately, but it occurred to me that they could be mixed.

If I recycle PLA and ABS together into one strand of filament, will there be any negative side effects (e.g. reduced strength)?

This is not a good idea. Both filaments have different melting points, that of ABS being much higher than that of PLA. To melt the ABS you have to heat the plastic to the point where the PLA starts to degrade.

yes but you would have to experiment with the settings to see were it afectivly melts.


DLP build plate adhesion Does anyone have tips on improving build plate adhesion in DLP printers? I've heard a thin layer of resin or UV glue applied to the plate will help, but we're not sure if we leave the resin/glue wet, or cure it before we start the print. Apologies for the ignorance here, but I'm just trying to avoid gluing my build plate to the bottom of the resin vat! Any advice would be appreciated.

Update
I had a product called ProtoGlass recommended to me in another forum, that apparently works as a good build plate primer for the resin we're trying to grow (BlueCast x5). Ordering today, and I'll update further with the results.

I have heard that adding a few pieces of masking tape to the print surface improves adhesion.


3D print a paint roller I was thinking about this question and thought of maybe printing a pattern-drawing roller painter.
The question is: is it possible to print with an ink absorbing material that could make a paint roller possible?
P.S: I don't own a 3D printer, nor have I any deep knowledge in this matter. I simply want to know if this is feasible, so I can start looking for someone to 3D print this for me. If it's not, knowing beforehand could spare me a lot of time.

While printing a roller stamp or rubber-roll from a flexible material such as [hard]TPU, [softer] TPE, or even a [super soft] foaming flexible filament is certainly possible. In any case, this would create soft, somewhat squishy prints. These prints will work quite easily as a stamp or woodblock printing stock, transferring ink from a pad to paper. The print pattern will depend a lot on how soft the stamp is: the harder, the sharper it will print. A massive roll of this material can behave akin to a rubber roll as one uses it in linoleum printing.
A foaming filament might be able to take a little paint in its airgaps, but it will never be as soft and contain as much paint as a foam lacquer roll - making it at best an improvised tool, or one that is chosen for a specific artistic purpose. It behaves more akin to closed-cell foam, while foam brushes and rolls from artist supply are typically open-cell ones. So if you go for a roller-stamp, you'll need to have an ink reservoir in the shape of a soaky-roller that isn't printed.
To top it off, it is nearly impossible to print a hairy wall painting roller: the hairs used in them can't be achieved with common print materials and slicers at the time. Even if stringing creates hair of similar dimensions, they are not affixed well enough to not get lost in the paint and can't be reliably created on demand.
Notes on pricing: One of the few options for foaming print materials is colorFabb, who was the first to offer such. Most of their foaming filaments cost around 50 €/kg, their flexible NinjaFlex costs about 80 €/kg.

I'm relatively new to 3D printing, but I know some stuff. If you really wanted to print a paint roller with a pattern, I would actually go with nylon or TPR. TPE is okay, but I find that it is less cushy. I would highly suggest buying your own printer for this project. It would be much more cost effective in not only the long run, but for testing different materials. 3D printing services get pricey, so choose your printer wisely. If you do decide to buy your own printer, I would go with an Ender 3 pro. Mine is very smooth, and has an easy-to-use interface.


Issue on 2 corners but not the other 2 I am printing using an Ender3 Pro with eSUN PLA+ 215/45 and I am getting this issue on two corners, the other two corners look fine.

Any idea on what can be causing this?

The bad corners

The good corners

This has nothing to do with speed, temperature, adhesion, and whatever you do, DO NOT extrude more material per line (increase flow rate), as this will make the problem that much worse.

This is a fairly simple problem with an even simpler fix: you're over extruding.  Reduce your flow rate by 5%, and see if that fixes the issue.  It will definitely improve it, but you might need to lower your flow rate a little bit more.

What can often happen when your flow rate is set too high is the extra plastic will concentrate at areas of relatively high acceleration (corners and the start/stop spot for a perimeter of a given layer), but depending on the size of the thing being printed and the degree of overextrusion, it won't concentrate at every spot like this on a perimeter.

Usually, I see this happen where the perimeter moves start and stop each time, which (again, depends on the slicer and settings) tend to be the same spot for certain models, often a corner.  I couldn't say for certain the exact mechanism, except that it seems like the plastic, given the right conditions, prefers to lay down evenly while the excess over extruded plastic builds up (probably carried by the nozzle, since it is hot and the plastic will want to stick to it) until too much has built up for the nozzle adhesion to keep it from sticking to the print, or the nozzle begins to decelerate (late at a corner or the end of a print move), causing the extra plastic to 'scrunch' up, like something that shoved in a distance too short for it.  Knowing this, if you examine the corners, it should be quite obvious that this is what is happening.  The perimeter is being extruded with more plastic than it should be, and the extra has a tendency to collect all in one spot each time.

Sometimes it is one corner, sometimes it is every corner, sometimes it is corners that are maximally distant from each other (since it takes some time for enough excess plastic to build up to over power whatever effects are preventing it from adhering immediately.  So in this case, the two good corners were just where not enough excess plastic had built up yet at the nozzle to cause problems).  Another possible explanation is that those two corners are simply where the perimeters were started and stopped, but some layers it was one corner, and other layers the other corner.  But you can see over extrusion artifacts lower down on the feet (or whatever they are), and your first layer as well.

Do not increase flow rate.

Do not increase infill.

Do not lower your speed.

Do not increase your temperature.

None of those will help, and increasing flow rate further could cause the nozzle to catch on the print, potentially damaging your hotend.

Just reduce your flow rate by 5%.  You should see an immediate improvement, or even elimination of the issue.  If it is still there, then reduce your flow rate a percent or two until it does go away.  And remember this number, because you'll probably want to use that flow rate in general for your printer.

Looks like it treated those corners a bit differently in the slice routine.  Normally something like this different treatment would be too slight to matter, but (probably due to the slight overhang?) it appears to have caused some layers to not adhere to the bottom ones and get pulled along to a different shape (red line in image).  (Be sure to check some general layer adhesion/overhang topics too.)

I'd try increasing the infill there (and using honeycomb style infill) or even using a cad software to hollow the interior to essentially a desired infill before slicing if the current infill is important elsewhere.

Moving slower, Increasing the temperature a bit, and/or extruding more material per line and layer if the layer adhesion is due to the slight overhang (although it looks pretty small).


Is there a spiral lid mechanism I want to put a spiral lid on top of a container. When the lid opens, then the spiral mechanism will rotate into the container. Is there a name for this mechanism? If not, would something like this be possible?

It sounds like you're talking about an iris diaphragm. This has many parts that slide against each other, and would best be printed as separate parts, then assembled.

No spiral lids that I know of. I'm not sure how they would work, anyway. There are plenty of designs with hemispherical lids -- so-called "Venus" boxes. Check Yeggi:

Yeggi : Venus box


Simulation tool software for 4D Printing In 4D printing technology or by means usage of Shape-memory alloy (non-metal, iron based, copper based or NiTi material) for 3D printing.
Is there any software simulation tool which I can use to simulate this material change behavior with respect to time?  For example, when introducing a change in humidity or temperature.
Note: It would be best if the simulation tools targeted automotive parts (power train, cooling system, interior & exterior etc.).

I am going to say that this probably is a whole dimension out of scope for this group ;-)
That said this new type of 3d printing is still at the University level. Also 4d is not necessarily 3d printing related at all. All it has to be is self assembling. Like http://www.selfassemblylab.net/4DPrinting.php
Unless you have a connect with MIT. Then you aren't going to be simulating any 4d models.
But if you HAD to do this, then you should write a paper about it and become a researcher. You could get published. You might need a PHD in material science. There might be some simulation in solid works.. but I would say you are mostly on your own and have to develop the models as they simply do not exist, especially outside of academia and stratasys.
That said if you take the "4d" part and use models based on the current understanding of the raw material you would have more success.

(preface : I originally intent to write this as a comment, but the volume limit reached. In that tone, I'll utilize this answer space writing it..)

  to simulate those material change behavior in respect to time?

COMSOL, ANSYS or equivalent ring a bell to be.. as long as you have the material properties (young's modulus, density, thermal transport & expansion properties, color?) right.

Also. depending on your actual implementation resolution (nano-scale production.. macro/mini-lego sized assembly), you may want to adjust the mesh size for the finite element method solver.

  software for 4D Printing

If your 4th D refers to time.. then the discussion ends here.

If your 4th D is a space (not time) dimension.. Then you need to convert your 4D geometric object into a 3D shadow (just like generating the normal 2D shadow from a 3D geometric object) 1st to proceed. just like an 3D object (eg cube) can have multiple equivalent 2D form (or shadow). The same applies for 4D to 3D. Once you get the 3D coordinates of the chosen 3D form, you may print it as usual.

Software wise.. mathematica (are used in the some of the example I've seen, others unknown/selfcoded) or equivalent will do.. but the key here is not the software.. it's the visualization algorithm. If you can get the "shadowing" algorithm done right, any 3D/math software will do.

p/s : I didn't expect the materials modelling question coming when I read the title (I really thought this question refers to extra space dimension) .. but yeah.. why not. It's a good postgraduate/research topic to take on. ( :