GearHeads Corner

5mm pitch HTD is easy as it can be done two ways, one is to drill a series of 1/8" holes on the pitch circle diameter and then turn down to the OD to produce the shape, second way is to use a 1/8" ball nose end mill or slot drill and cut it in the vertical just using the 4th axis as an indexer.

I am not sure on the other pitches, I really need to call in the bearing company and grab a few to measure what diameter fits best.

John S.

Here's their "technical" (sales) brochure.

Page 104 touches on the tooth form, but I think it was translated from "accurate" to "inaccurate" by the marketing department.

They spelled tractrix wrong.

The tooth form is patented, which means you should be able to find it defined in the patent document.

I noticed that the "pitch circle" is out where the reinforcing fibers of the belt are.

I'm not sure what "involute form of a catenary" means. Maybe they mean catenary involute, but I'm having trouble seeing how to apply that to a pulley.

--Justin