1. Geometry is set by using the appropriate involute cutter

2. I can't remember what cutting speed I used last time I machined SRBF, but the key to machining plastic is low speed and high feedrates. Too high a speed and the plastic melts. At a guess a 16DP cutter is going to be about 2.5" diameter, I'd run it at 100-200rpm, no coolant.

3. Cut to full depth in one pass

4. SRBF can chip where the cutter leaves the work, so it may be beneficial to use a sacrificial spacer of the same material on the exit of the cut

Regards,

Andrew

The advice given to me was always to cut the tooth to full depth in one pass. Multiple passes risks errors in indexing the blank.

As Neil says, to reduce the risk of chipping or delamination, use a sacrificial blank (aluminium?) behind the workpiece.

If you are cutting gears in a laminated material, use the material so that the laminations of the gear teeth are not in shear.

i.e use sheet for the blank, rather than rod. This may seem obvious, but many years ago, a motor manufacturer did not, and a lot of Idler Gears lost their teeth, because of this.

Howard