spur gear stock for custom gears

[petertha]

I'm finally turning towards my 'design project' again... meaning the thorny issue of making matching valve timing gears to a defined (commercial) internal ring gear. I stumbled on this spur gear blank stock. If I understand it correctly, should solve a lot of issues. Hopefully the catalog link will transfer ok, but also attaching screen grab.

https://sdp-si.com/eStore/Catalog/Group/591#

They say 'carbon steel' & nothing about hardening. I'm wondering if I could carefully chuck up a length, center bore & part off to my own dimensions. Seems like a lot less work than modifying one-off gears that I see available. Any experience with this?

 

[stevehuckss396]

I used it to make a pair of pulleys for a timing belt. Works great. The gear stock is a bit pricy so If I only need one gear of a specific tooth count I typically modify a stock gear if possible.

 

[Brian Rupnow]

Most gears are not hardened. You should have no problem buying the stock and boring the blank to whatever you need it to be. The only trick part is holding it in a chuck to bore and having the bore come out concentric to the pitch diameter of the gear. Probably better to bore a blind hole in a round piece of aluminum to the exact o.d of the gear stock, then sawcut a split to a center hole so that the jaws of the chuck will close up the sawcut and grip the gear in a manner which holds it concentric for boring.---Brian

 

[stevehuckss396]

Or make a simple holder for the correct od of the gear. I have a half dozen of them here somewhere. Worth the half hour they take to make.

 

[Chiptosser]

If you have collets that run true, just chuck it up in them.

The other thing that I do, is take soft copper sheet and wrap the O. D. Then use a three jaw ( adjustable) or the four jaw.