.STL to SETP conversion - Page 1
Forum section: electronics / general

author: DenCraw
author_rank: Contributor
timestamp: June 06, 2023, 10:19:05 am
content: Hi.I have made 6 plates with some holes in Tinkercad.It produce 3 types of files one is .STL.I need to convert that design into SETP for a CNC machine.since my knowldege on other CADs is Zero, can anyone may orient me in how to do it?.Perhaps i can share the files or the tinkercad link privately.Thanks for any help.

author: TERRA Operative
author_rank: Super Contributor
timestamp: June 06, 2023, 10:47:22 am
content: I assume you mean STEP?.stl is a polygonal format, it is akin to the 3D version of a pdf file. Convenient, but a pain to edit.STEP is a format that is based on solid modelling, not polygons. A step file may allow for polygons but unless your software is a solid type modeller or can export as such, you might be out of luck.When I have an STL file and I have no access to the original files or STEP, sometimes I have to resort to re-modelling the part in an appropriate piece of software (I use Rhinoceros 3D).It's a pain, but it's like trying to convert from a pdf file back to the original word document.....

author: HighVoltage
author_rank: Super Contributor
timestamp: June 06, 2023, 11:38:40 am
content: For such a task, I import the .STL into solidworks and then save it as .STEPOther CAD programs might work the same way.

author: abeyer
author_rank: Frequent Contributor
timestamp: June 06, 2023, 07:28:58 pm
content: I think the supported way of doing this from tinkercad is the "Send to Fusion360" route... but of course that means you need F360 (and probably would have just started there.)I think the free version of onshape is another tool that will also do the import/export thing, but typically you will lose accuracy doing that.

author: SiliconWizard
author_rank: Super Contributor
timestamp: June 06, 2023, 08:29:54 pm
content: With FreeCAD you can do the opposite (import a STEP file and export to STL for 3D printing), but STL to STEP has never worked for me. I just tried again and it fails to export with some 'NULL shapes' errors.I don't know if it's even supported or not.As TERRA Operative said, the formats are pretty different, and transforming STL to STEP, when some software actually allows it, will often result in a very sub-optimal STEP file that will be hard to use for CNC machining. But maybe SolidWorks does very clever stuff here, I don't have a license at the moment to test it out.

author: abeyer
author_rank: Frequent Contributor
timestamp: June 06, 2023, 08:45:22 pm
content: Quote from: SiliconWizard on June 06, 2023, 08:29:54 pmI dunno about supported, but I seem to recall making it work -- I think you need to bring the stl into the mesh workbench, do some manipulation on it there first to make it happy, then convert the mesh to a solid, then export the solid as step. Something like that, anyway, it's been a while as it's a last resort kind of thing to even attempt.

author: SiliconWizard
author_rank: Super Contributor
timestamp: June 06, 2023, 10:23:35 pm
content: Looks like a nice adventure.

author: Infraviolet
author_rank: Super Contributor
timestamp: June 06, 2023, 10:36:16 pm
content: One can take a 2d slice from the stl model as a dxf, many CNCs systems, especially for those optimied for 2d shapes like the plate you discuss will take dxf inputs.Look at this:https://github.com/frezik/laser_slicerThe syntax for use ispython laser_slicer.py --input PATH_AND_NAME_OF_FILE_TO_SLICE--end-height= HEIGHT IN MM --start-height= HEIGHT IN MM --layer-height=HEIGHT IN MMI've used this to take dxf slices from mesh modeleld stl files.Regrettably I fear that converting stl to step is effectively impossible, stl is a mesh geometry which represents objects by triangular (or quad) faces, every face is contained in the file. STEP is a file based on procedural operations and descriptions "put a 3mm hole here..." like procedural CAD. Going from step to stl is like taking a screenshot, trivial, you can select how many mesh sides you want to use to represent step's perfect circle and other things like the "resolution" forthe mesh object to be made at... going from stl to step would be like wanting to go from a screenshot image back to the actual text on the screen (and a much uglier problem than optical character recognition).

author: TERRA Operative
author_rank: Super Contributor
timestamp: June 07, 2023, 01:29:25 am
content: One way I think of it is a STEP is like the 3D equivalent to a 2D vector image, an STL is like the rasterised version of that image.

author: SiliconWizard
author_rank: Super Contributor
timestamp: June 07, 2023, 05:23:08 am
content: Speaking of that, I use OpenSCAD on a regular basis and it does not support generating STEP files, which I would find very useful.Does anyone else use it too?

author: TERRA Operative
author_rank: Super Contributor
timestamp: June 07, 2023, 05:39:08 am
content: Can't you link it in with FreeCAD to generate STEP? I seem to remember doing something sort of like that to convert the parts for one of the Prusa 3D printers to STEP.

author: DenCraw
author_rank: Contributor
timestamp: June 07, 2023, 06:40:05 am
content: Oh man! this solve my problem.Thank you very much.the other answers are correct but requires some manipulation.

author: SiliconWizard
author_rank: Super Contributor
timestamp: June 07, 2023, 07:46:49 pm
content: Quote from: TERRA Operative on June 07, 2023, 05:39:08 amOh, you're right. FreeCAD does support OpenSCAD format via .CSG.Just tested - export your design to .CSG from OpenSCAD, open the .CSG file in FreeCAD, select the object, export to .STEP.Just works.

author: TERRA Operative
author_rank: Super Contributor
timestamp: June 08, 2023, 01:25:13 am
content: I think you can maybe even go one step further and do some sort of plugin thing in FreeCAD to allow FreeCAD to natively open OpenSCAD files.I don't remember the details though as it was years ago and the OpenSCAD/FreeCAD workflow isn't compatible with my brain.

author: DenCraw
author_rank: Contributor
timestamp: June 08, 2023, 08:55:05 am
content: I'm stuck again.Thinking I'm happy to have saved the file in STEP AP203, STEP AP214 and IGES, they tell me that the curves of the holes and cone holes for screws are planes and not curves.That I should do the drawing in Solid, not in CAD. and my brain explodes when I see the number of software options.I naively took the tinkercad and thougt that is a piece of cake, and results in a piece of ... other thingy.any ideas or help will be appreciated.I can't post the SETP file because is 55MB (8 MB compressed)

author: TERRA Operative
author_rank: Super Contributor
timestamp: June 08, 2023, 11:20:41 am
content: If your STEP file is 55MB, it's either a really complex design, or it's actually polygons, hence the mention of faces and not curves.Can you scratch out a drawing, even on paper and take a photo and upload it so we can see what it is?If it's simple and you provide dimensions, I might be able to draw it up if it won't take more than a few minutes.

author: Infraviolet
author_rank: Super Contributor
timestamp: June 08, 2023, 02:24:39 pm
content: My advice is go back to your initial CAD file (tinkercad in your case)k export each model as an stl (pikcing among any options tinkercad gives you for resolution, if it says something like "how many sides ought to define a 360 degree circle" pick something like 48 to get a reasonable curve without excessive file size). Then knowing what you know about the stl file's dimensions use that laser slicer script to make one slice through each stl at a height half way up the stl's height. Your situation is 2d so dxf is suitable, I wouldn't be surprised if FreeCAD might be able to make a 3d extruded STEP file (albeit not very editable as it would have come from a dxf consisting of lines rather than from procedural CAD descriptions) if you imported the dxf to it.

author: TERRA Operative
author_rank: Super Contributor
timestamp: June 08, 2023, 05:52:26 pm
content: I have the files from DenCraw, spent just a little time so far rebuilding the files as solid objects, wasn't too hard as they are simple shapes and they are all looking nice and clean now.Just need to know what font is used for the text, and for the logo I just need a vector or outline or even an image could be maybe be used.

author: TERRA Operative
author_rank: Super Contributor
timestamp: June 09, 2023, 01:07:58 am
content: Hooo boy, that 3D design was all over the place....STL rounding errors, holes not aligned, even some holes were made to be blind when they shouldn't.... The file needed a complete redraw.Anyway, once I know the font used, I'll have it finished in a snap and it'll be perfect.If getting it CNC'd you will find a lot of the detail in the text and logo will be lost due to the minimum radius of the cutting bit used (and thinner cutting bits means slower machining speed which means higher production cost), I would suggest a simple font if you wanted engraved text or maybe look into screen printing or inkjet or similar for the text and logo etc.

author: DenCraw
author_rank: Contributor
timestamp: June 09, 2023, 07:37:04 am
content: Hi, good morning here.The font is BEBAS NEUE.Ill attach it to this message.Regarding the miss aligned holes.I am new to the software so i select tinkercad because naivly tought that can cope with my goals.I discover the aligment tools so i have started by a selected point as a reference.the grid was always on 0.01mm which is the minimum for tinkercad.I thought the alignment was perfect.Your job overwelmed me. I thank you so much this hand you bring me .see you

author: TERRA Operative
author_rank: Super Contributor
timestamp: June 09, 2023, 01:11:07 pm
content: Hi,Are you sure that is the correct font? It doesn't seem to match very well...

author: DenCraw
author_rank: Contributor
timestamp: June 09, 2023, 01:47:41 pm
content: Hi.Sorry. I thought you were referring to the logo font.That font is Sans Mono.

author: TERRA Operative
author_rank: Super Contributor
timestamp: June 09, 2023, 02:10:27 pm
content: Still doesn't match. I'm about to give up here if I can't get the right info from you......

author: DenCraw
author_rank: Contributor
timestamp: June 09, 2023, 02:34:20 pm
content: I found one that match better with tinkercad font.same name.

author: DenCraw
author_rank: Contributor
timestamp: June 12, 2023, 07:43:51 am
content: I am deeply grateful. Thank you very much!