Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Builds, Repairs, Show Your Machines! => Technical Tips, Builds, and Help => Topic started by: Jim on July 23, 2026, 10:24:46 pm

Title: Re: Hobbing a Brass or Aluminium Drive Pulley to Stop Belt Slippage
Post by: skeptic49 on July 25, 2026, 05:55:01 am

I enjoyed your video. I only wish i had the equipment and skills to use a lathe, etc.

Title: Re: Hobbing a Brass or Aluminium Drive Pulley to Stop Belt Slippage
Post by: Stoker on July 24, 2026, 06:55:32 pm

Hey Jim .... seen your hobbing plenty of times and think it is really great, though I rarely experience any serious belt slip, but then I don't run very load heavy accessories much. Really need to build myself a Baker Fan some one of these days ... but I digress.

What I would like to ask you is what sort of pulley groove do you prefer to do your hobbing on. I realize it can be done on most any form of groove, but am wondering what you find works best a slightly flared U-shaped groove or a V-shaped groove? If you prefer a V-shaped groove, what angle do you find most effective, 90, 120 or some other degree of divergence???

Title: Hobbing a Brass or Aluminium Drive Pulley to Stop Belt Slippage
Post by: Jim on July 23, 2026, 10:24:46 pm

I've posted up photos before of hobbed pulley drives. It's a process that works very well and gives a professional result (very similar to what Wilesco does on their drive pulleys). I've done well over a hundred brass and aluminium drive pulleys now.

Here's a vid I did a few years ago of the process -

https://www.youtube.com/watch?v=adQg7KxkGf8