hybridfree/eevblog-posts huggingface dataset:
What software to use with my cheapo laser engraver / CNC? - Page 1
Forum section: electronics / general

author: ncot_tech
author_rank: Newbie
timestamp: November 05, 2021, 02:30:00 pm
content: I have one of those cheapo Chinese laser engraver / CNC machines. One of those "3018 CNC Engraving" things.Anyone know the workflow to make things with it? Like, if I have an idea in my head and I want to 3D print it, I fire up Fusion 360, make the part, export it, put it into Cura to slice it and then send the gcode to my printer. What's the equivalent for these cheapo CNC machines? I know the end step is "load grbl file into Lasergrbl and press the go button" but nobody seems to have a sensible first part.How would I, for example, get a vector image and turn that into something I can send to the machine to engrave? Firing up Fusion seems like a bit of an overkill when the real laser cutters just seem to accept photos/drawings and it looks like a five minute job.I am aware there's a reason the real machines cost 10x more than these cheapo things, but still ...

author: Kean
author_rank: Unknown
timestamp: November 05, 2021, 02:44:49 pm
content: I use Fusion360 for complex parts, but for many years before than and still now for simple things I use software called CamBam (not free, but trial availble).If you want something free and simple, then I believe Inkscape can generate G-code. Probably good enough for simple engraving.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: November 07, 2021, 06:51:58 pm
content: I have a home-built CNC machine.I put GRBL into a "Blue Pill", then added 74ls244 buffers (I had some lying around) and these drive the opto couplers in Nema 23 stepper motor drivers.Schematic is pretty simple and it's a one-off, so I just soldered it on matrix board.On the software side I use bCNC.bCNC can read some vector formats (It can read DXF, and maybe also SVG). My CNC is not a laser thing, but a mill / router. with bCNC I can do multiple passes on different depths and it also has post processing options for adding tabs and vector sorting.There are also plugins for Inkscape that can generate G-code output.

author: beanflying
author_rank: Super Contributor
timestamp: November 08, 2021, 01:45:28 am
content: Depending on the firmware and board you have fitted look at the following freebies for a play.Candlehttps://github.com/Denvi/CandleGRBLGruhttps://www.grblgru.com/Universal GCode sender (UGS)https://winder.github.io/ugs_website/
fascinatingly simple metal curved piece assembly method - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: November 07, 2021, 07:31:34 pm
content: So I have had problems in the past where I would try to form flat bar over a radius and it was a not too controllable. It seemed hard for me to cobble together things to work with flat bar.This technique allows high control in simple fixturing without advanced tools, so long you are willing to cut metal afterwards. The bent angle iron can be turned into a flat bent piece with careful cutting, so long you mark a scribe line before you cut. Of course I would prefer to torch the flat piece out of a larger sheet, but you must notice if you need a long flat piece in a small shop, keeping/cutting stock material like this may be unreasonable, but throwing a few long angle irons on the back of a shop shelf is barely even noticed.The problem with just banging on a flat bar is that it has very little stiffness so you need to bang it sideways sometimes I think and it ends up being screwed up, but with an angle iron it should be drastically more strait.
Mini tabletop saw question - Page 1
Forum section: electronics / general

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: July 04, 2021, 09:44:40 pm
content: https://www.aliexpress.com/item/1005002914162581.html?spm=a2g0o.productlist.0.0.565f300csZavsg&algo_pvid=1755a5a2-a963-4de2-a847-82b60911655b&algo_exp_id=1755a5a2-a963-4de2-a847-82b60911655b-16Think this thing can cut 2020 aluminum extrusions? I mean as a hobby, one cut here and there, slow as molasses. But will it work at all?I mean it has a heat emission hole and everything. But all I see are the chips falling straight into the motor.

author: EPAIII
author_rank: Super Contributor
timestamp: September 22, 2021, 06:41:32 am
content: 96 Watts is a bit over 1/10 HP. Not much power. But my Unimat table saws (I have both the metal and the wood versions) are powered at about that level with it's motor. However with a three stage pulley system on the Unimat, they can be operated at a wide range of speeds. So by lowering the speed I can get more torque. Speed is for cutting wood, torque is needed for cutting metal.The 5000 RPM sounds more like a wood saw than a metal one. You may get by with aluminum, but then you may not. For aluminum, about 500 to 900 RPM is more in line with what the size of that circular saw blade looks like. And 1/10 HP may be OK, but 1/2 HP would be a lot better.Good luck.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: October 30, 2021, 05:44:41 am
content: Have you considered buying a regular circular saw and then build a table for it yourself?
Dear All.. Is NVIDIA's road is the best for a Robotics Start-Up? - Page 1
Forum section: electronics / general

author: salihkanber
author_rank: Regular Contributor
timestamp: October 24, 2021, 08:39:12 pm
content: Dear All.. This is Salih, Founder of Sunday Robotics.. I am trying to decide the route to take for our AI and DeepLearning goals. NVIDIA is doing a lot today, would their ware be the best route for a Robotics & AI Start-Up? Can I have your suggestions? Thanks.

author: rstofer
author_rank: Super Contributor
timestamp: October 28, 2021, 05:00:26 pm
content: For small projects, the NVIDIA Jetson Nano is interesting as is the Coral Dev Board (Google product). These both support full Linux as well as specialized cores for all the math required. But the number of cores is fairly small - 128 in the case of the Nano.For larger projects, I'm not aware of any company even coming close to the NVIDIA graphics cards with over 10,000 CUDA cores. That's a LOT of parallel computing.The new $1,500 RTX 3090 has 10,496 cores, for 36 teraflops. We went to the Moon and back using machines capable of 2-3 megaflops!You can do a lot of machine learning with 36 teraflops.https://www.engadget.com/nvidia-rtx-3090-3080-3070-cuda-core-int32-fp32-210059544.htmlTensor cores are the new big deal - worth searching Google...

author: salihkanber
author_rank: Regular Contributor
timestamp: October 29, 2021, 09:13:31 pm
content: Quote from: rstofer on October 28, 2021, 05:00:26 pmThat is fantastic, certainly more than we need right now but I see the potential. For a Robotic start-up that deals with Rasp Pi's right now, its a bit confusing to create the path, since we can't have it all, the best way would be to focus on a specific problem and try to develop robotic and AI solutions upon it. Don't you think?
ceramic silver sintering process flat kiln (burried/packed elements) - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: October 21, 2021, 03:24:52 am
content: So there is a video and a discussion thread in the RF forum about the applications, but I have questions about the process.https://www.youtube.com/watch?time_continue=1233&v=kxXEI0Ce6C0&feature=emb_logoSo he has something along the lines of a high temperature waffle iron... with exposed coils.. but I am wondering about something I saw.There is a youtube video some where that shows how thermalyene kilns are made, and the unique feature that those kilns have is that there is no exposed coils, when I watched the how its made video, it showed the coils being essentially cast into the refractory mix (embedded inside like a mattress box spring). I like how it becomes a 'heating block' that is fairly rugged.I never saw thermal design guides for making a kiln with 'burried' elements, they are almost always laid in trenches and stitched into place. I was thinking to trench firebricks and then put in the element then manually seal the springs in by applying whatever kind of paste is used...does anyone have a design guide for something like Kanthal wire being used embedded in refractory.. i.e. maximum watt density guidelines, etc.I expect the design will have a shorter life time and lower surface (if you can still call it that) watt densities then a conventional kiln but it just needs to basically get a thin film of glass molten.. maybe it can be done. I would just like it alot more if it was a flat smooth block that gets hot on the bottom then some kind crazy spring thingI know this is done on some tube furnaces, and it has a slightly bad reputation, but this is seriously low volume experimental prototyping. I find things usually work better for me if its more like imagined then less.I also thought about using some kind of nichrome sheet corrugation structure that is resistance heated, but I am not sure what the requirements of the power transformers would be (so its just put over the board like a gazebo)
Describe to me how this relay voltage doubler works - Page 1
Forum section: electronics / general

author: Qmavam
author_rank: Regular Contributor
timestamp: October 15, 2021, 09:20:38 pm
content: OK, it's a simple circuit, but I can't understand how the negative side of the capacitor goes to negative 6v. (I assume that's what happens)Also, explain the function of the diode to ground. I understand if you tied it to ground it wouldn't work, but what are the currents in the diode.Thanks, Qmavam

author: TimFox
author_rank: Super Contributor
timestamp: October 15, 2021, 10:02:14 pm
content: The 220 uF cap and the lower 1N4148 diode form a negative "DC restorer" (q.v.). Regardless of the DC level on the positive terminal of the capacitor, the negative swings at the positive terminal will pass through it and the diode establishes the baseline as near ground. (The diode keeps the negative end of the capacitor from going substantially positive with respect to ground, and the charge in the capacitor will hold the voltage across the capacitor somewhat constant.)

author: H.O
author_rank: Frequent Contributor
timestamp: October 16, 2021, 03:13:08 pm
content: I'll take a stab at this, hopefully I won't make a fool out of myself :-)When the BC547 is "off" so is the BC557. The capacitor gets charged thru the 2k2 resistor and the bottom diode. If you measure the voltage between "ground" and the positive terminal of the capacitor you'll see around 6V. The voltage across the capacitor itself will be slightly less (~5.5V) due to the bottom diode.When the BC547 turns on it A) turns on the BC557 which "connects" the high side of the relay coil to the 6V rail and B) "connects" the high side of the capacitor to ground. Remember how the voltage across the capacitor was roughly 5.5V. Now, with the capacitors positive terminal pulled to ground there's still 5.5V across the capacitor and therefor its negative terminal will be roughly 5.5V below ground and there will be roughly 11.5V across the relay coil - for a short time.
Casimir effect plates? - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: October 14, 2021, 12:18:13 am
content: So I was wondering about the whole lapping laboratory/workshop thing I had in mind for quite a while and I am wondering what the flatness requirement of plates would be to get the cashmir effect to work.I read the separation between plates is under 10 nanometers, which is0.000000393701 inchesFor comparison, a AA surface plate is 0.0001 inches per meter or 0.0000055 per 2'' (seems like what you would imagine bench top experiment to be, looking how the pictures are presented)So if I did the math right, the AA surface plate is only 14 times less accurate then necessary for giant 2 inch cashmir plates?I know this is probobly really inaccurate but its surprisingly hard to find information on what this would look like, because of cookware websites.Assuming you got something to AA grade surface plate level, how is it further flatened? I assume that the plates they made were made through some forms of self leveling molecular deposition or something.. no one actually managed to flatten something that far conventionally, have they? can you slowly peel off atoms using some kind of laser, zapper machine, etc? I was imagining a scanning ion beam that they can slowly grow things with high resolution by molecular bombardment... but I suppose maybe guidance is a problem (you get an uneven surface within the 'bombardment zone')I say '14 times does not seem like alot' because I have no idea if lapping has some kind of catastrophic limit where it does not function anymore that makes "14 times" = infinity. Usually peoples interests go no further then gauge blocks, but this effect obviously shows the need for a flatter structure.

author: Benta
author_rank: Super Contributor
timestamp: October 14, 2021, 08:20:28 pm
content: Are you talking about the Casimir Effect?Never heard of "kasmir plates".

author: coppercone2
author_rank: Super Contributor
timestamp: October 14, 2021, 08:30:38 pm
content: yeah, I see its written a few different ways. I mean the plates that are associated with zero point energyI imagined two plates inside of ball positioners with peizo actuators to vary the distance, it seems that piezo stacks with 1nm adjustment are possible (16 bit 100VDC power supply is a requirement). Maybe it would require a few piezo stacks for the polar axis alignment with thick'living hinge mechanisms', if manually adjusted ball is not good enough, to get it to 'curl' the plate in the correct direction with a few force vectors. I would built it press fit with a very thin paper coating that can be removed when its assembled so the piezos/micrometers can do their work to correctly align the mechanism to be parallel when its 'fixed' with a say 0.001 inch paper in place, so all the mechanisms would be focused on bringing an approx 0.001 inch gap to 10 nm.
dji mini 2 bms - Page 1
Forum section: electronics / general

author: advanced DJI series team
author_rank: Newbie
timestamp: October 12, 2021, 04:11:55 pm
content: I want to get rid of my dji mini 2 bms UNLOCK all battery, what are the steps with patboonlab, TRB?the problem is the rise in critical battery mode ,, the voltage is reduced and the rise is at 3.3 km, I would like to eliminate the voltage drop thank you
3018 pro max power supply issues - Page 1
Forum section: electronics / general

author: vu2tve
author_rank: Contributor
timestamp: January 15, 2022, 11:19:26 am
content: Hi, I had ordered a YoFuly 3018 CNC pro max machine a year ago, and finally got around to assembling it today. Once assembled I plugged in the offline controller and also installed candle on my ubuntu/mint machine.The CNC comes with a 200W spindle and an SMPS which says its rating is 24V/10A.Now, I am facing the following issue. When the CNC is connected to the computer and I give a command to turn the spindle on, it looks like the machine temporarily power cycles. I connected the 24VDC line to a DSO and the dip in voltage is quite clear (and astounding!)I'm pasting photos of both the oscilloscope and the power supply.Has anyone using these chinese CNC machines faced similar issues? Is there an easy fix, or should I just bite the bullet and get (or make) a 24dc supply rated for atleast 200W (maybe more). Would putting a big ass capacitor somewhere help?The product is not under any kind of warranty so I don't mind opening the power supply and seeing what can be done to it.Thoughts?

author: vu2tve
author_rank: Contributor
timestamp: January 15, 2022, 11:34:26 am
content: well.. I put in a 470uF cap at the 24VDC terminal and the spike is no longer huge, but it is still there, and the board does not reset.I'll just open the smps and put in a big cap and that should be it.

author: SmallCog
author_rank: Frequent Contributor
timestamp: January 17, 2022, 10:29:09 pm
content: I ordered one of these after Christmas and I must admit that whilst I've played with it I haven't probed it.It is my intention to replace the included power supply with something reputable when I get around to it, probably something from Meanwell or similarThese tend to have exposed terminals but it would be in conjunction with making a box for the machine to dampen noise and catch dust so I'll kid proof it at the same time (I have some very enthusiastic young helpers)The supply it has works, but being an unknown ebay thing I trust it about as far as I could throw itHope you're as happy with your machine as I am with mine

author: vu2tve
author_rank: Contributor
timestamp: January 17, 2022, 11:34:39 pm
content: I'm getting some time to play with it, so looking forward. I'm new to any kinds of graphic/3d design, so something new to learn for me. The power supply issues are fixed as I put a 3300uF/35V electrolytic cap, and a ceramic cap in parallel along with an indicator led on the 24v wire out of the adapter.
Solar battery powered autonomous robot ... - Page 1
Forum section: electronics / general

author: myked
author_rank: Newbie
timestamp: October 18, 2021, 09:57:26 am
content: I'm trying to build a small wheeled robot that is powered by a battery that is charged by a small solar panel. The idea is that the robot stops trying to move until there is a sufficient charge and then moves until the charge drops. The solar charging needs to be itelligent so that it maintains the battery in good health and does not overcharge it or allow it to over-discharge. An Arduino needs to be powered as well as the two small electric motors for the wheels.The main problem I'm having is finding a solar charging manager that can handle the load which I think might peak at 2A due to the elecric motors which I planned on driving through an H-Bridge circuit.The very promising DFRobot DFR0535 module is perfect other than the fact that is can only provide 9V at 0.5A to the H-Bridge.Any comments gratefully received.

author: salihkanber
author_rank: Regular Contributor
timestamp: October 26, 2021, 08:22:12 pm
content: Dear myked, you will need the charger for the solar panel-battery side, whenever there is sunlight, the charger will do its job, IMHO you won't need a 2A charger there. Battery-load side can be under control of the arduino, it can check the battery voltage through its analog inputs, and when its below the threshold value it stops. You can start doing this by a literature search, similar projects, schematics, and then constructing your own schematic.
getting polish on loose buffs - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: July 22, 2021, 09:25:36 pm
content: So I want to polish up some male banana contacts that are chassis mount on some stuff and I thought a good way to go would be green rouge on a loose buff on a dremel wheel. By loose buff I mean you can have solid wool buffs, stitched buffs, and loose buffs, the loose one looking kind of like a dainty flapwheel.I have trouble getting solid compound on these buffs. With a stiched, sisal or wool buff, you press it in hard enough and it gets an appreciable amount of compound on it, but the loose buff just slaps along the surface.Is there a trick to this? I have only been using liquid compounds (i.e. brasso, chrome polish, etc) on these buffs because its easy to apply. Are my compounds just too tough? are these for liquid only?https://cmpstone.com.au/product/loose-leaf-calico-buff/You can have stitched, semi stitched or totally loose, I am using the ones that are minimally stitched.

author: jpanhalt
author_rank: Super Contributor
timestamp: July 22, 2021, 11:08:24 pm
content: I have never had a problem applying stick polish to a loose buffing wheel. That is a standard wheel on my buffer. Never tried the liquid polishes. Why use them when you know something easier works?

author: coppercone2
author_rank: Super Contributor
timestamp: July 23, 2021, 01:44:26 am
content: have you tried to use the little one on a dremel? I can hardly get any loadingthe liquid polish are pretty good actually, I did the banana jacks with automotive chrome polish and it came out greatI think they kind of do chemical-mechanical polishing so you get some properties you don't normally get from just pure abrasive
rubber durometer and type for transformer mount - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: July 13, 2021, 04:42:56 am
content: so I have some nice transformers I want to mount and I remember when I got a big torroid it came with a rubber sheet but these little guys did not. I don't see a reason why not to get rubber sheet to put them on.I thought to get 1/8 inch rubber, but there are different durometers available. I don't know whats good. Any suggestions?Also, should I choose a particular type of rubber? I.e. fiberglass rubber, etc.

author: floobydust
author_rank: Super Contributor
timestamp: July 13, 2021, 05:26:43 am
content: A rubber sheet I don't think is useful because the vibration goes through the four mounting screws.How many VA and lbs?I've used thegeneral purposeneoprene mounts with 8/32 studs on 1,500VA, about 28lbs. These say Durometer 50A medium. Small weight is around 7lbs each x4 for 28lb but I might have bought the 20lb each for 80lb capacity.For some reason, the core vibrates quite a bit even at light load in a steel chassis, but it's totally quiet on these mounts.Toriodal transformers have the rubber disc to prevent the windings from getting mashed by the mounting washer, and they have an insulator to prevent making a shorted turn with the mounting hardware.

author: coppercone2
author_rank: Super Contributor
timestamp: July 13, 2021, 07:12:49 am
content: yeah its the rubber disk I mean, I know its not perfect but I think it does somethingI thought I can put two disks when I do it myselfmaybe I can consider the neoprene mount too but it seems better to bolt it to a plate then glue the plate down with rubber, I have done that in an experiment

author: coppercone2
author_rank: Super Contributor
timestamp: July 15, 2021, 05:11:31 pm
content: I bought flurosilicone sheet to try out

author: floobydust
author_rank: Super Contributor
timestamp: July 15, 2021, 07:49:56 pm
content: I have an old sheet of 1/8" neoprene, used to cutout and make gaskets. That would work too.For acoustic noise, it gets conducted through the mounting bolt(s) even though on a rubber cushion, so that can limit it. The transformer vibration can also be due to nearby steel grabbing some flux, so moving or rotating it can make it quieter too.
Two phase VS Three phase Din mounted power supplies - Page 1
Forum section: electronics / general

author: V_King
author_rank: Regular Contributor
timestamp: July 05, 2021, 12:32:52 pm
content: Hello,I wonder if anybody could clear out the confusion in regards to two phase power supplies.I have an induction motor, running off a three phase VFD. I need to add a small 24VDC power supply, so that logic would be powered separately on the VFD.On MeanWell website I have a choice between:1. WDR series power supplies, which as I understand could be wired into two out of three phases and should support 24VDC. Example:https://www.meanwell-web.com/content/files/pdfs/productPdfs/MW/WDR-60/WDR-60-spec.pdf2. TDR series power supplies, which just simply power off all three phases.https://www.meanwell-web.com/content/files/pdfs/productPdfs/MW/TDR-240/TDR-240-spec.pdfPlease ignore the current ratings of the PSU, question is about Uin side of things.I really want to avoid have a five wire feed into the control cabinet and do not want to use the Neutral for the single phase power supply (not available as it is installed at the moment). Two phase Uin is half a price to three phase Uin. The feed into the VFD is 32A three phase.Then only issue with two phase power supply I could see is unbalanced phase loading, but would that really matter, when VFD is 15kW and the PSU taps in half an amp? Or do I not understand something?Maybe there is some white paper I could ready to build a better understanding?

author: Berni
author_rank: Super Contributor
timestamp: July 05, 2021, 12:50:38 pm
content: The "Two phase" PSU is actually just a regular single phase input PSU, except that it has a unusually wide input supply voltage range that lets it be powered from higher voltage between two phases.You can simply feed neutral and one phase into that PSU and it will work fine. Phase imbalance also is not an issue since most loads plugged into single phase outlets are simply using one phase out of the three. So your little PSU is not going to matter if someone else can plug a 1.5kW space heater into the wall outlet.The benefit of having three phase input for a control cabinet PSU might be to make sure the control cabinet keeps working if you loose a phase. Tho the VFD is likely to quickly become upset about that and safely shut itself down anyway.

author: BeBuLamar
author_rank: Super Contributor
timestamp: July 06, 2021, 01:26:23 pm
content: It wouldn't make much of a different because the power supply doesn't draw sufficient power to cause phase imbalance. However, if I have 3 phase power in the cabinet I would use a 3 phase power supply.

author: elekorsi
author_rank: Regular Contributor
timestamp: July 06, 2021, 02:19:46 pm
content: You can use the first one without problems, just put in there a 2 pole circuit breaker to protect both phases. You can connect it between any of two phases as long as the voltage is in the specs, which i asume it is (400V?)It is good practice to not use the neutral in the industrial cabinets. Even if you need some 230V for some auxilary circuits (cabinet lightning, service outlet, etc.) it's nice to use a 400V/230V transformer...
any open source digital-measuring tape? - Page 1
Forum section: electronics / general

author: DiTBho
author_rank: Super Contributor
timestamp: April 24, 2021, 10:40:27 pm
content: I need to build one with the resolution of 1mm, the tape I need should measure things within 2m.Let me know

author: ledtester
author_rank: Super Contributor
timestamp: April 29, 2021, 06:56:40 pm
content: There's also this idea:

author: Doctorandus_P
author_rank: Super Contributor
timestamp: May 03, 2021, 05:34:06 pm
content: Such a mouse has a tiny camera in it.If you use a regular tape measure and a webcam fixed to it, you can use image recognition software to analyse the position of the measure tape.If you also look at the numbers on the tape measure, you can even make it an absolute encoder.Camera modules can be quite small and cheap these days. The bigger problem would be a brainbox with enough brain power to run the image recognition algorithms, and small battery drain power for a decent lifetime (If it's battery powered).

author: EPAIII
author_rank: Super Contributor
timestamp: July 20, 2021, 09:49:08 am
content: I was also thinking about a 2 meter tape measure. But you don't need any fancy image recognition, just a few optical readers (photocells focused on the scale). And a mark on the back or a small hole drilled in the tape can serve as the zero reference. A few logic chips or a processor like Arduino or just a plain PIC could easily handle the logic.Quote from: Doctorandus_P on May 03, 2021, 05:34:06 pm

author: ebclr
author_rank: Super Contributor
timestamp: July 21, 2021, 05:50:39 am
content: As a reference a product ready to do thathttps://www.aliexpress.com/item/4000289371852.html?spm=a2g0o.productlist.0.0.6f0e3c9fFaDSHE&aem_p4p_detail=202107202248572800956441060960005714073

author: DiTBho
author_rank: Super Contributor
timestamp: July 22, 2021, 12:02:33 pm
content: Quote from: EPAIII on July 20, 2021, 09:49:08 amA friend located in Estonia sent me a very unique "soviet ultrasonic sensor", and I made a contact-less measuring unit under the precision of 50mm, with a range of 300...900mm. It requires a very precise 16bit timer able to operate with a scale of 10usec. Nice piece of semi-vintage technology (I think the ultrasonic parts were made in 2010) but in original soviet color and shape. It's big and heavy, and looks like something bade during the cold war, but I like it.Then I bought a couple of industrial meter-tape units, and I attached an optical-flow on the top, this way the optical sensor is able to read the marks on the tape. It works with the precision of 2mm, with a range of 10..1200mm. It requires a 50Kbit/sec SPI line and 2Kbyte of ram of the pattern-image.
Etching aluminium enclosures. - Page 1
Forum section: electronics / general

author: Shiv
author_rank: Regular Contributor
timestamp: June 25, 2021, 11:41:50 am
content: Hi all, I had some ferric acid (FeCl3) and I made this pedal for my brother.Recipe:1 part Ferric acid (mine is 39%) + 1 part hot water (about 50ºC)Transfer made with brandless yellow transfer paper, if you have press & peel, should be easier.About 50 minutes submerged upside down.I´m happy with the result so here it is:

author: esepecesito
author_rank: Regular Contributor
timestamp: June 30, 2021, 05:05:43 pm
content: Amazing. Thanks for sharing!

author: Just_another_Dave
author_rank: Regular Contributor
timestamp: July 03, 2021, 02:23:42 pm
content: Wow! It looks amazing!
bevel star washers making tool (HF) - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: April 01, 2021, 06:05:20 am
content: So I know this machine exists, I saw it years ago on youtube from harbor freight but I just cant recall the name or find it.Basically sometimes you want a star washer to go into a chamfuer hole, i.e. in HP equipment. I saw a jig a while back that looked like a buncha bowl shaped craters in a metal block, with holes iirc, so you put the washer in, then put a appropriate ball bearing on top, then bend it into a bowl shape some how (press or hammer).It cost like $25. Does anyone know of the kit? or an alternative? I think it was made for making belveill type washers or something.I thought to drill a chamfuer hole into a steel block and try it that way, but IIRC the geometry of this was rounded, rather then inverted cone.. I think that leads to better bends\it had like 20 of those craters and bearings so you can do various sizes

author: Kean
author_rank: Unknown
timestamp: April 01, 2021, 12:13:20 pm
content: Are you sure it was for shaping washers for chamfered (countersunk) holes? As you mention, I am pretty sure it would be for making Belleville Washers? I believe those are indeed formed using a ball bearing, although they are referred to as "conical" washers when actually they're more like a dome with a bit missing.I've never seen a press like this for sale, although I have no doubt they exist. It does seems to be a bit too niche for a place like Harbour Freight. If you have access to lathe and mill then it is something you could knock up pretty quickly for use on a small press. For production purposes it would be hardened.

author: Derick Freese
author_rank: Contributor
timestamp: May 28, 2021, 05:21:52 pm
content: Sorry for the late reply, but I think this is what you were looking for:https://www.harborfreight.com/hand-tools/chisels-punches-stamps/25-piece-doming-block-and-punch-set-93539.html

author: coppercone2
author_rank: Super Contributor
timestamp: May 28, 2021, 06:00:55 pm
content: yes thats it, I have a few more HP repairs coming up so maybe when I loose more washers and screws I can look into it to do a bulk chassis repair at a value

author: bill_c
author_rank: Regular Contributor
timestamp: May 28, 2021, 09:03:22 pm
content: That is a neat tool (posted above) to have .I swear I am not affiliated with McMaster Carr.But you could just buy them already shaped for about the same cost.https://www.mcmaster.com/standard-washers/lock-washers/countersunk-external-tooth-lock-washers/Or even cheaper if you can find them elsewhere.

author: jh15
author_rank: Frequent Contributor
timestamp: May 29, 2021, 01:17:02 am
content: Hehe the picture of the wooden base says dombing block.

author: JohnMc
author_rank: Contributor
timestamp: May 30, 2021, 12:34:38 am
content: The tool is also known as a Dapping block.
rub on metal platings? - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: May 10, 2021, 03:12:15 am
content: So, other then silver kool-amp (great stuff), are there any rub on platings that are out there?I am particularly interested in a rub on tin plate. I see alot of stuff as electrolytic or dip plating, but not really rub on. I like it because the powder stores well and its nice to work with, plus you don't have to deal with solution tanks.By rub on, I mean that you dampen a cloth (i like the deoxit polypropylene wipes for kool amp), sprinkle it on top, then rub on the very clean surface until it reacts and the plated surface results. I see they sell tin plating concentrate as a powder, I am not sure if this will work in this manner without dilution. I thought maybe?
Using a sensorless ESC on hall sensor hoverboard motors? - Page 1
Forum section: electronics / general

author: jshaul
author_rank: Newbie
timestamp: April 28, 2021, 06:15:35 am
content: A hoverboard motor is (usually) a high torque 3-phase brushless motor with a hall sensor controller.But, asit is possible to run them without.What would I be losing in this application? Torque? Efficiency? And would using an alternate encoder (say, on an oDrive, which doesn't support hall sensors to my knowledge) rectify the issue?

author: ace1903
author_rank: Regular Contributor
timestamp: April 28, 2021, 11:54:44 am
content: Hoverboard usually does short rapid movements back and forth when started in order to maintain balance.Without feedback it will be difficult to obtain system stability.ESC measures induced voltage in the windings in order to calculate rotor position.When starting and on low speed, voltage is so low so it is difficult to measure it and produce control signals accordingly.So I will say that you will loose system stability and starting riding on hoverboard will be risky moment.

author: jshaul
author_rank: Newbie
timestamp: April 28, 2021, 04:44:39 pm
content: Quote from: ace1903 on April 28, 2021, 11:54:44 amFortunately, I'm not using it in a hoverboard - just a glorified go-kart. It just needs to go forwards and backwards; nothing fancy.

author: ace1903
author_rank: Regular Contributor
timestamp: April 28, 2021, 07:06:21 pm
content: For go-kart it should be fine with generic ESC.Now on second thought, I have never seen go-kart that can go backward.So I think that you will gain possibility for easier maneuvering during parking using this new reverse option in this automatic shifter.
Dirac Belt Trick Mechanism cleverly avoids twisting wire - Page 1
Forum section: electronics / general

author: mathsquid
author_rank: Frequent Contributor
timestamp: March 17, 2021, 04:45:46 pm
content: This is an interesting video I ran across. A cube is turned continuously, but the string attached to it doesn't get twisted.More info:https://en.wikipedia.org/wiki/Plate_trick

author: Circlotron
author_rank: Super Contributor
timestamp: March 25, 2021, 01:10:11 am
content: I wonder if you could somehow use that principle to construct a homopolar disc generator or motor that doesn't need slip rings?

author: domika
author_rank: Newbie
timestamp: April 24, 2021, 04:29:08 pm
content: this is a good project

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 25, 2021, 01:55:56 am
content: Quote from: Circlotron on March 25, 2021, 01:10:11 amHmm, perhaps. But is the solution worse than the problem -- how are you going to get all that current out? Surely not through cables, the amount of flex requires a lot of slack and discourages large amounts of it.Somewhat related mechanism:Tim
Rack and Pinion solution for V-Slot Aluminium - Page 1
Forum section: electronics / general

author: beanflying
author_rank: Super Contributor
timestamp: April 08, 2021, 07:35:29 am
content: No home for this in particular and it is a new product to me. There has been bolt on Metal options for a while but this is now a lost cost alternate for lighter duty applications. So if you dislike long belts on your CNC projects look it up.Precision plastic and inserts into V-Slot Aluminiumhttps://www.makerstore.com.au/product/gear-m1-int-500-d/should be available elsewhere too. Downside is locally they only have 1/4" Pinions to suit NEMA 23 Steppers but I would most likely be running a reduction drive to this so adapting to NEMA X would be easy. Possibly ok for lighter duty routers too but generally there are better options with Ball Screws.Redesign on my Foam Cutter project is a bit of a no brainer as it simplifies the design a lot and removes 3m Belt runs and the stretch issues that go with it. Seriously now considering a re design of my 1200x800 Laser cutter even though I have all the bits in stock for it.

author: AmnevaR
author_rank: Contributor
timestamp: April 08, 2021, 07:24:39 pm
content: An interesting product indeed. But I can't figure out how to avoid backlash without some ''tension'' spring.There is of course a "driven nut" design (https://www.linearmotiontips.com/whats-the-difference-between-a-ball-screw-spline-and-a-traditional-ball-screw/), really small backlash with it, but the cost for a long screw will go through the roof

author: jpanhalt
author_rank: Super Contributor
timestamp: April 08, 2021, 09:02:55 pm
content: Wonder whether made for a worm gear to minimize backlash and improve holding?

author: beanflying
author_rank: Super Contributor
timestamp: April 09, 2021, 12:21:05 am
content: Backlash can be controlled by the depth you insert the pinion into the rack. The Pinion teeth are not flat cut as per below so adjusted properly are on the back and front face of a rack tooth at the same time.Side note Module 1 like this stuff it actually Pi (3.1415926.......) Pitch so drawing it 'accurately' in CAD kind of sucks due to rounding issues. The drawing and dimensions on Makerstore are poor approximations of the maths if you try and use them in a model so tweak as needed.

author: beanflying
author_rank: Super Contributor
timestamp: April 09, 2021, 03:41:07 am
content: Possible solution/idea for a Maker Rail/Plate build. Two 6mm high spacers above the wheels and a 3D printed Housing containing the pinion and two 1/2 x 1/4 R188zz Bearings sitting on a 1/4" shaft. In my case I am going with a 3mm Stainless plate or if you go with Aluminium with a cutout then 5-6mm might be needed to keep the rigidity across the cutout. M3 screws and knurl nuts for fasteners.Quick check of the housing it will print fine without supports due to tweaking a few faces internally.
YDLIDAR TG15 - Page 1
Forum section: electronics / general

author: Luka_b7
author_rank: Newbie
timestamp: March 20, 2021, 11:05:45 am
content: Hi,i work on one project where i'm using YDLIDAR TG15. I want to make self driving robot car using LIDAR, but without ROS and SLAM. Almost everything i found on internet was with ROS, but i have no time to learn ROS from 0 and i want to do something just with LIDAR, raspberry pi 3 B+ and Arduino Due. I have some issues because i dont know how to process LIDAR's data. So, i have scan and all data's from LIDAR but i dont know how to use them with obstacle avoidance algorithm. Do i need map or i can do it without map? I am using Python 3 for programmming and i have RT RRT* algorithm, but i generate obstacles with pygame. I am not sure if i can use this algorithm also with LIDAR. If do, how can i then use data from LIDAR to implement them with this code? I am sharing with you one part of code in Python where i generate obstacles with pygame.def makeobs(self):obs = []for i in range (0, self.obsNum):rectang=Nonestartgoalcol = Truewhile startgoalcol:upper = self.makeRandomRect()rectang = pygame.Rect(upper, (self.obsDim, self.obsDim))if rectang.collidepoint(self.start) or rectang.collidepoint(self.goal):startgoalcol = Trueelse:startgoalcol = Falseobs.append(rectang)self.obstacles = obs.copy()return obs

author: DiTBho
author_rank: Super Contributor
timestamp: March 20, 2021, 01:26:46 pm
content: what is "RT RRT* algorithm" ?

author: DiTBho
author_rank: Super Contributor
timestamp: March 20, 2021, 01:28:47 pm
content: Umm,thismust be you. I will look and follow that topic.
Control software for drone? - Page 1
Forum section: electronics / general

author: zenerbjt
author_rank: Regular Contributor
timestamp: August 09, 2020, 06:31:49 pm
content: Please could you possibly point the way for someone to get auto-pilot software for designing and building a drone? Ie the control software to keep the drone level in flight, or make it go right/ left etc...ie control of the motors.Also, we have a weather drone which will go up on a wire from the ground. The wire carrying electric power for the drone.Do you please know how we can get software to manage the winch to this drone so that we can manage the paying out and reeling in of this drone's wire so that the wire doesnt get too slack or get tangled?

author: StefanHamminga
author_rank: Contributor
timestamp: August 14, 2020, 07:24:34 am
content: You mean something likehttps://ardupilot.org/orhttps://betaflight.com/?

author: oliviasmithh900
author_rank: Contributor
timestamp: March 07, 2021, 01:22:10 am
content: There are many Arduino ArduPilots available, they are all pre programmed and have Arduino libraries for interfacing with Arduino.

author: ElektroHS
author_rank: Contributor
timestamp: March 17, 2021, 03:53:26 pm
content: you can check paparazzi uav, px4, Dronecode etc. There are ~10 projects that can be interested for you.

author: ElektroHS
author_rank: Contributor
timestamp: March 17, 2021, 03:55:21 pm
content: You didn't specify what a hardware you are going to use. You should check which of projects is corresponding to your hardware.

author: cgroen
author_rank: Unknown
timestamp: March 17, 2021, 03:55:53 pm
content: Only around 49.000.000 hits in Google....https://bfy.tw/QYuU
[Math] CNC tool path generation from point A to point B - Page 1
Forum section: electronics / general

author: blueskull
author_rank: Unknown
timestamp: February 04, 2021, 05:19:33 am
content: As the title suggests, what is a good tool path generation algorithm for moving from point A at PA(x, y) with velocity VA(x, y) to point B at PB(x, y) with velocity VB(x, y)?Naively, one may think just find the acceleration A(x, y) so that by the time the object reaches PB(x, y), the velocity reaches VB(x, y).However, this does not work all the time, as in the real world the system has a maximum motor winding current, thus a maximum force, thus a maximum acceleration, so the acceleration must be capped at Amax.Furthermore, for power supply stability reasons, I would prefer the acceleration to be kept constant at +-Amax or zero, so for each axis, only 3 possible acceleration values can be used, +Amax, 0 or -Amax.Given the constraints, what is a good strategy for this problem?I do have a naive solution that I will post later, but I'd like to know if there are other solutions.Regards,B.G.

author: jmelson
author_rank: Super Contributor
timestamp: February 18, 2021, 03:56:13 am
content: You have a trajectory generator that puts out a series of points from the beginning to the end of the move, calculating the number of intermediate points needed to get the desired velocity.Then, you have a PID calculation that compares actual position to commanded, and figures out what to do with the motor to minimize following error.Have a look at LinuxCNC, this has all been worked out 25 years ago.Jon

author: KrudyZ
author_rank: Frequent Contributor
timestamp: February 18, 2021, 04:41:32 am
content: Limiting yourself to +- Amax or zero acceleration is generally a bad idea.The transitions release energy that is stored in the flex of the moving parts which will then ring.If you want more information on this, look up "jerk". It's the third time derivative of position, after velocity and acceleration.
Bachmann PLC Software - Page 1
Forum section: electronics / general

author: remap128
author_rank: Newbie
timestamp: December 01, 2019, 07:24:38 pm
content: Hello,I have got a Bachmann M1 Series PLC set. It looks great - a lot of analog and digital IO etc, great thing for learning.The problem is that I don't have the software, could please anybody share a link or file?Thank you for support.

author: rvalente
author_rank: Frequent Contributor
timestamp: September 26, 2020, 02:56:48 pm
content: Pretty old topic but....http://plcforum.uz.ua/is best place for this kind of request, give it a try.
good brand of mini buffs? - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: March 27, 2021, 11:28:42 am
content: So the ones from dremel are expensive... I was reusing them alot but I thought it would be cool to have a 50 pack.SO this time I actually bought the cheap product to test it myself, they totally suck. I would call them one time uses, you cannot clean them like the other ones and they shed like crazy making a huge mess of nasty abrasive coated fibers where they operate.I bought the cheap kit on amazon. Their mechanical properties are trash and I hate touching them.Is there a good value non disintegrating kit?If anyone is curious, I also bought a cheap kit of scotch brite 1/8 shank abrasive pads, and these are actually.. worth it.. the dremel ones are obscenely priced and do not last very long, these are at least similar at a much better value, its not a hard decision to decide to use them, with with the cost of the dremel ones it was like using a superpower ability in a videogame.
Looking for PLC with multiple RS485 and CAN - Page 1
Forum section: electronics / general

author: davorin
author_rank: Unknown
timestamp: June 05, 2020, 09:37:56 am
content: Good morningFor a new project I am looking for a PLC or other controller which has at least:- 4 * RS485- 1 * CAN- 4 digital inputs- 2 DC outputs 24V@2AMost PLCs I've found so far have only 1 or 2 RS485 interfaces...thanks in advancedavorin

author: greasemonkey
author_rank: Contributor
timestamp: June 17, 2020, 05:51:21 pm
content: I don't know what your budget is but I would suggest a modular OMRON PLC.CPU CJ2https://industrial.omron.eu/en/products/cj2CAN CJ1W-CORT21https://industrial.omron.eu/en/products/CJ1W-CORT21RS485 2x CJ1W-SCU32https://industrial.omron.eu/en/products/CJ1W-SCU32Grüsse aus Innertkirchen

author: senso
author_rank: Frequent Contributor
timestamp: July 18, 2020, 12:41:10 pm
content: Why so many RS+485 buses?Also that CJ2 combo will be expensive...RS-485 to some industrial comm standard is common and would be way cheaper.

author: rvalente
author_rank: Frequent Contributor
timestamp: August 29, 2020, 08:49:24 pm
content: The siemens s7 1200 can hold up to 3 comms modules in the left side, as well as one 485 in the cpu. So you could get 4x485 or 3x485 + 1can.All these 485 runs different protocols/bauds?