Drawing 100 tooth HTD 3M timing pulley

[oldmachine]

I deleted constraints #25 & #26. Okay now...

[ljoets]

Thanks

[RFB]

This is a tutorial that I prepared for a 5 mm pitch HTD sprocket but with some substitution it will generate the tooth profile for a 300 pitch sprocket. All of my engineer came from Gates Rubber with the exception of the belt tooth width and end radius. Gates doesn't publish that information nor will they provide it for and individual. In my case the belt tooth measured .110 or 2.8 mm and that corresponded with the dimension that I found on a competitor's site. You need that dimension for the red circle used in generating an involute curve. The point spacing is (( teeth * 3mm) / 360) and they aoo rotate together 1º with 30 copies. Trim the bottom segment of the curve to Y axis and then mirror the tooth Geometry on Y axis and the rotate the Geometry 3.6º with 99 copies.

Replace 5 mm with 3 mm
Replace 30 with 100
Replace .045 with .030" - see picture
Replace .0818898 with .048

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