CNC machining metals. - Page 1
Forum section: electronics / general

author: harps
author_rank: Regular Contributor
timestamp: September 11, 2020, 01:48:45 pm
content: Hello there.I am hoping to find a popular cnc free software program, equivalent to how Eagle is to PCB design.When i learnt how to make circuit boards, I used Eagle and it was great because there were detailed youtube tutorials online and it was free,After the Gerber files were made I sent them to a company and it arrived at my doorstep at a very reasonable cost. It was a great journey to take.I believe it was thanks to one of Daves videos that I found eagle many years ago.The 3d objects I hope to cnc are small, under 10x10x10cm. I am not 100% sure which metal? I would like titanium, but the cheapest to start withmight be best, just in case I make a mistake. lol. Also only in very small quantities, one off's or just pairs at a time.Thanks for any help : )

author: sokoloff
author_rank: Super Contributor
timestamp: September 11, 2020, 02:39:27 pm
content: If it’s hobbyist work, I’d use Fusion360 and stop there. (It’s free-as-in-beer for hobbyists, just like Eagle.)I spent a lot of time in OpenSCAD for modeling for 3D printing and still use it for some extremely simple parts, but wished I’d switched to Fusion earlier. It includes CAD and CAM functionality.

author: Mecanix
author_rank: Frequent Contributor
timestamp: September 11, 2020, 05:05:54 pm
content: Manufacturing metals require a machine-tool (mill, lathe, etc). Its supportive controller software (hmi), CAM capabilities and other post-processors comes next. PS. You need to be experienced to machine TI. Not that's its more difficult than any other materials; it is extremely hazardous in term of work-hardening e.g. end-mill shattering, machine stalls/crashes, sparks igniting 'extremely dangerous' fires (seen a titanium fire before?!), etc etc. I'd recommend AL alloys before any others to begin with.If you want to learn solid modeling (CAD) then that is a whole other area on its self. If the end goal is to be able to manufacture your own parts I'd recommend to get familiar with CAM and understand the limitations of modern NC machine-tools (so to be able to model parts that are able to be machined down-stream).

author: harps
author_rank: Regular Contributor
timestamp: September 11, 2020, 05:46:11 pm
content: Quote from: sokoloff on September 11, 2020, 02:39:27 pmThank you, I shall check out fusion360. Sounds cool. nice one

author: harps
author_rank: Regular Contributor
timestamp: September 11, 2020, 05:53:00 pm
content: Quote from: Mecanix on September 11, 2020, 05:05:54 pmHi my hope is to design a part but have an expert/company do the maching from the file.Thanks, i am glad you mentioned to read up on limitations of what the tools can do...I shall do. And I assume from this, how to keep a design cheap to produce also, by not trying to do things that are too complex for a machinist. Kind of like sticking to single or double-sided circuit boards, before going multilayer.thank you

author: Benta
author_rank: Super Contributor
timestamp: September 11, 2020, 06:01:38 pm
content: +1 for Mecanix.Ti is a nightmare to machine. It smears when cutting and work-hardens at the same time, meaning climb milling is the best approach, which again means you need a very rigid machine.The aluminium-built XY tables with high speed spindle are not suitable.I suggest you work with free-machining Al instead. If you want a Ti-like look, there are surface treatments for Al that look like that.

author: olkipukki
author_rank: Frequent Contributor
timestamp: September 11, 2020, 06:07:05 pm
content: Quote from: harps on September 11, 2020, 01:48:45 pmYou can always try services as xometry.com (or alternatives) to check what would be 'reasonable cost' to machine an one-off from titanium...

author: MarkF
author_rank: Super Contributor
timestamp: September 11, 2020, 06:46:34 pm
content: Fusion360 is not free.I have been usingFreeCADfor my 3D prints.It has its bugs but has been getting the job done for me. Plus lots of how-to videos.

author: sokoloff
author_rank: Super Contributor
timestamp: September 11, 2020, 06:56:06 pm
content: Quote from: MarkF on September 11, 2020, 06:46:34 pmFusion360 is free (as in beer) for personal use. That's at least as free as "equivalent to how Eagle is" IMO.Quote from: harps on September 11, 2020, 01:48:45 pmhttps://www.autodesk.com/products/fusion-360/personal:Quote

author: harps
author_rank: Regular Contributor
timestamp: September 11, 2020, 07:40:21 pm
content: Quote from: olkipukki on September 11, 2020, 06:07:05 pmThanksi like that they will give a quote when the user uploads a file to the site. with all the different metal options to choose from. :

author: harps
author_rank: Regular Contributor
timestamp: September 11, 2020, 07:42:39 pm
content: Quote from: MarkF on September 11, 2020, 06:46:34 pmi have just been getting into fusion360 this evening,it really is cool. But now you mention 'freecad', maybe that would be better as my designs are simple and i hope to keep it all cheap as chips(fries). I shall have a look, thank you.

author: olkipukki
author_rank: Frequent Contributor
timestamp: September 11, 2020, 07:51:03 pm
content: There is always something else for 'free'and don't require be in a fusion cloudhttps://www.eevblog.com/forum/eda/free-cad-solid-edge-community-edition/

author: harps
author_rank: Regular Contributor
timestamp: September 11, 2020, 07:57:26 pm
content: Quote from: olkipukki on September 11, 2020, 07:51:03 pmThanks I am checking it out now. : )

author: harps
author_rank: Regular Contributor
timestamp: September 11, 2020, 08:05:38 pm
content: Quote from: olkipukki on September 11, 2020, 07:51:03 pmI'm not keen to have to be connected to the internet to use the software, is that required with fusion360?Regards solid edge, I notice it has a commercial option.I may want to sell a part one day so maybe freecad might be best? as it seems to be offline and totally free?

author: sokoloff
author_rank: Super Contributor
timestamp: September 11, 2020, 09:28:13 pm
content: Quote from: harps on September 11, 2020, 08:05:38 pmhttps://knowledge.autodesk.com/support/fusion-360/troubleshooting/caas/sfdcarticles/sfdcarticles/Unable-to-open-Fusion-360-without-internet-connection.html#You have to be connected to the internet to download and install it.You have to be connected to the internet every couple of weeks to continue using it.Just now, I was able to disconnect my internet connection and use it to design and save a very simple part just now, so for the "I'm going to do some design work on an airplane trip", it seems like it would probably work OK.I was NOT able to convert that part to an STL file for 3D printing without internet.

author: olkipukki
author_rank: Frequent Contributor
timestamp: September 11, 2020, 09:38:30 pm
content: Try FreeCAD and see if it will fitorFusion360 if don't mind be online.I will be more concerned about a learning curve, availability learning stuff, personal usability, public popularity...

author: harps
author_rank: Regular Contributor
timestamp: September 12, 2020, 09:47:58 pm
content: Quote from: olkipukki on September 11, 2020, 09:38:30 pmhi i tried freecad and found that I can move a circle or a point with the mouse freely...but i can't type in the values directly, there is no dialog box that shows the xyz position. I have never seen a program like this without the xyz dialog box. unless there is a hidden tab?for example I make a sketch on a side of a box, I then make a circle and can move it around, but I can't place it exactly, by typing in the xyz parameters. i have to place it freehand with a mouse., surly i am missing something here?

author: harps
author_rank: Regular Contributor
timestamp: September 12, 2020, 09:56:55 pm
content: Quote from: MarkF on September 11, 2020, 06:46:34 pmhi mark. is there a hidden xyz dialogue box in freecad? When I am placing a circle in a sketch I have to use the mouse freehand. I can see the xyz pop up on the screen as I hold the mouse button down, and when i let go of the mouse button the xyz numbers vanish. no where in any tab can I then fine tune the placement. very unusual for a 3d package not to have xyz to fine tune. it must be me, surly.

author: Cerebus
author_rank: Super Contributor
timestamp: September 12, 2020, 10:38:57 pm
content: I'd like to sound a note of caution. It's very easy for someone without machining experience to take a 3D cad program and design a part that is almost impossible to manufacture, or will cost much more to manufacture than a functionally equivalent part that is designed by someone who has some insight into the machining process.Say you have a pocket in a part (pocket in this sense is an arbitrary shape hole in a part that only goes part way through the part). Say you decide that it wants a 1/4" wide 45º chamfer between the walls and the floor of the pocket. That puts you into the territory of needing a 5 axis machine to do the machining rather than a cheaper 3D machine, or requires a lot of setup on a 3D machine, or requires a non-standard cutter. Whichever way you machine it, it costs more than a simple pocket with straight sides that meet the bottom at 90º. If you need a pocket like that for functional reasons, fine you bite the bullet and accept the cost. But a naïve design might include such a pocket without considering the manufacturability of it. Hopefully you can see where this goes for all sorts of other features, for knowing how to design a part so that it can be held in the machine while machining and so on.Before you design parts and kick them off for someone else to manufacture you can save yourself potentially a lot of grief by learning a bit about the machining processes. You don't have to become an expert, just learn enough to be able to give a rough answer to 'how would you make this on a mill/lathe?'. Like, is this feature milled, or drilled, or drilled and reamed, or bored, or produced with a slitting saw, or turned. And to have an answer to "How do you machine all the features I want on this part while still being able to hold it (usually in a vice) to machine it?".You can get a lot of this just from watching some basic machining videos on You Tube. There are worse starting places than the basic milling and lathe courses put together on the 'blondihacks' channel on You Tube. If you want to have a laugh and also watch some machining 'ThisOldTony' on You Tube is good value, but not as deliberately educational as blondihacks. Somewhere on You Tube is a series of videos on machining that MIT put together for students who needed to use the workshops to make parts but didn't have any machining experience - search for "MIT Machine Shop Videos".

author: harps
author_rank: Regular Contributor
timestamp: September 12, 2020, 10:53:56 pm
content: Thank you for the suggestions for the youtube videos and not using curves on edges unless really needing them.I shall make note for tomorrow to watch them.thank you again : )

author: Mecanix
author_rank: Frequent Contributor
timestamp: September 12, 2020, 11:08:15 pm
content: Quote from: Cerebus on September 12, 2020, 10:38:57 pmNothing worse than to receive a model from cad dept having 45 degree chamfered edges and corners at the bottom of cavitiesMy fav; non-tangent curves and/or mismatching spline tolerances & surfaces (3D), or plain and simple lack of geometric constraint references. Some solid models for mfg could indeed ruin a CAD designer overnight by the CAM engineer stitching them up in prep for machining. In most cases ending up a totally different part for 10x the price lolYour message is strong and important; its not because you are being given some cool 'pro modeling tools' for free and know how to add volume to a 2D sketch with a mouse-click that it makes you a parts & assemblies maker. Far from. The learning curve about manufacturing and processing those parts is pretty steep in all realities (3~5 years learning curve minimum, with hands-on).

author: MadTux
author_rank: Frequent Contributor
timestamp: September 12, 2020, 11:43:27 pm
content: 45º chamfer at the bottom of a pocket is rather easy to do, if you have a (tool) grinder, just grind the end of the cutting edges to a 45° angle and proceed as normal.Much worse, people who want like 50x M2 threads in aluminum. Or difficult contours for absolutely no reason.Undercuts/deep pockets are also nice, some people probably think the cutter just comes out of nowhere and the material disappears into thin air.....

author: Mecanix
author_rank: Frequent Contributor
timestamp: September 13, 2020, 12:22:07 am
content: Quote from: MadTux on September 12, 2020, 11:43:27 pmI'd swing this over the 5ax guys for a tilted op only if required by the engineer himself/herself (and being operational feature that is, I doubt though lol). All that to say; trust I've seen this sort of stupidity and other rather alien-world geometries a lot during the last few recent years. Particularly grown problem since F360 is free and youtube hypes the 'free-hand' CAD amateur like I've never seen before. To a point we've completely stopped taking outside jobs and phone calls from unknown people, its that bad.

author: MarkF
author_rank: Super Contributor
timestamp: September 13, 2020, 01:08:46 am
content: Quote from: harps on September 12, 2020, 09:56:55 pmIf you select an object, you can type values in the lower left corner.For pads, fillets, chamfers, rotations, etc., you can type values usually in the left Model or Tasks tabs.This guys tutorial series helped me a lot:He also does a comparison between FreeCAD and Fusion360.

author: MarkF
author_rank: Super Contributor
timestamp: September 13, 2020, 01:23:48 am
content: Quote from: sokoloff on September 11, 2020, 09:28:13 pmWhen you get to this point in FreeCAD, you need to highlight your part and then"File -> Export -> STL File" for something you can slice for a 3D-Printer as an example.(No save function to a STL file.)

author: harps
author_rank: Regular Contributor
timestamp: September 13, 2020, 01:13:22 pm
content: Thank you Mark i shall check out the video today!!I include pictures below on what i see.I make a sketch, I drop in a square. When I drop it in, the rotation is active, and it is hard to put it just right.so i drop it in anyway, intentionally at 50degrees and at a random size, and then look to see how i can alter thesize and rotation to exactly 45 degrees and say 50mm x 50mmThere is no dialog box that shows anything near the rotation 50degrees i set when i dropped it in, or the sizeDo i have to give it a reference constraint first? does it not know what i am looking at or what I just did?https://ibb.co/zPkqrxYhttps://ibb.co/gVS9NHtI cant get the pics to show up on the forum, but hopefully you can view them when clicking.thanks for your help.: )

author: harps
author_rank: Regular Contributor
timestamp: September 13, 2020, 03:48:37 pm
content: Quote from: MarkF on September 13, 2020, 01:08:46 amThank you Mark, I see, so it has to have a relationship, a relative point to be constrained too before any parameters can be inputted.I kinda thought and did try but must have been using the wrong constraints.I use 3ds max from time to time, and to make a box I click drag drop, and then there are boxes to fine tune positon and size. very easy.it would be cool if after dropping the shape into freecad there was an option to automatically set all constraints to a preselected point, and then the user could simply fine tune tune the shapes positions by typing in numbers.The program is pretty cool, and your links are great too..thank you

author: CatalinaWOW
author_rank: Super Contributor
timestamp: September 13, 2020, 04:54:10 pm
content: I use FreeCad. Cloud free and really, really free, with zero chance of becoming not free. But there are downsides. Most important, like any free software, future development and support is chancy. More chancy than successful commercial programs.And as you have found, the user interface is not smooth. Once you learn what is going on it is usable, but there are many things that just aren't easy.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 13, 2020, 04:59:52 pm
content: So why do you need a software program that is CNC free?TL;DR most of it.If Open Source is an important issue, I've not found a better program then FreeCAD, It has not reached version 1.0 yet, but it's getting into a state that is "quite usable", but it's not yet very polished.For controlling my CNC machine I use one of the STM32 clones of GRBL which work quite nice.I've been tinking about looking into FlatCAM, but have not done much with it yet.About eagle...The Eagle has Crashed, long live KiCad.

author: MarkF
author_rank: Super Contributor
timestamp: September 13, 2020, 05:37:54 pm
content: Here is another video tutorial series:It shows some advanced howto for springs and threads.These tutorials show entering the values in millimetres.You can also input values in inches by first deleting the popup value and units; then, entering value and 'in'.The value will be converted to 'mm' and displayed as such.If you always want to use inches, you can set the default units from Tools -> Preferences menu.You can also enter values with math functions (i.e. add, subtract, multiply and divide).I haven't tried complex expressions.Also, I seem to remember you can use variables so that same values don't need to be entered more than once.Makes it easy to make changes if needed.

author: harps
author_rank: Regular Contributor
timestamp: September 13, 2020, 07:01:01 pm
content: Thanks again for all your help!!! I think freecad is the way to go for me. There is steep but short learning curve at the start , but it is a necessary step to take.Thanks to the tutorial links from Mark, it makes it all allot easier to get past that initial step and enter the doorway to freecad world. It really is like the Eagle equivalent. Cool