Full Version: Looking for timing pulley script?

Any one know of a MOI3D script for generating timing pulleys using standard timing belt parameters for common timing belts, eg, GT2, HTD, etc.?

I occasionally have a need to 3D print a timing pulley but my efforts to recreate the GT2 profile using MOI3D has been average at best. Using MOI3D, I've managed to design a reasonably accurate belt profile but I'm painfully learning that the mating pulley profile needs 'tweaked' a bit for a quality fit.

I've also located a couple of OpenSCAD programs that generate STL files for parametric timing pulley designs, but I've yet to find a simple method to convert the STL files to STEP. So making changes / customizing the OpenSCAD exports is problematic. Seems I recall that Fusion360 can import STL files and export STEP files with some effort? I tried the same conversion using FreeCAD but the conversions never worked.

Thanks for any suggestions.

Scott

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Hi Scott,

Gearotic may be able to generate those profiles.

But an easier method would be to modify a STEP file from McMaster-Carr like this one:

https://www.mcmaster.com/3684N11/

Regarding STL to STEP conversion: that's not a file format conversion; it's going from geometry made up of flat triangles to geometry represented by smooth curves. Doing it right is pretty complicated and is likely to create accuracy issues.

- Peer

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Gearotic can generate many timing pully profiles in DXF or STL format but it's $120 USD.
I have Gearotic and if you need a few pullys generating I'm happy to do them for you.

Martin.

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https://woodgears.ca/gear/

Wayne

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Freecad has also gearmaking option.....which is the only reason I use it.

https://www.youtube.com/watch?v=bDLlQiTl5XI

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Thanks to everyone for your suggestions.

Not sure why I overlooked the McMaster STEP file option given I routinely download their STEP files. I should be able to use their pulley tooth profile(s) to meet my needs and if not I can try to export the DXF and/or PDF's from OpenSCAD and then use MOI3d to capture the tooth profile. I did re-discover today that the Thingiverse OpenSCAD pulley generator script includes a 'tolerance' variable for fine tuning the actual 3D prints. My 3D prints to date are useable but not an optimum fit due to the typical 3D print tolerances for small dimensional shapes. So this 'tweaking' variable should really help dial in the best dimensions without a lot of tedious drawing iterations.

Thanks again. This forum definitely adds value to the wonderful MOI3d program!

Cheers

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