How are chain sprockets made?

[DennisCNC]

HI,

Are they cut like gears or another method is used?


Thanks

[High Seas]

Dennis - I don't know - and sure someone will - but you've seen the clock gear info here on the 'zone right? They sure look like sprockets too. Seems like a simple enuf approach and very DIY.
Jim

[miljnor]

they are usually cut with a hobbing machine similar to gears.

we mill the profile at my work. but a hobbing machine is faster and arguably faster.

[Geof]

In decreasing order of accuracy: hobbing or horizontal milling (these are similar) using profile cutter cutting across the width of the sprocket, end milling, laser cutting, abrasive water jet cutting, plasma cutting.

A profile cutter or hob gives the best quality because it crosses the sprocket and produces sprocket teeth that have parallel sides. With end milling the cutter can deflect out and produce a very slightly tapered sprocket. Laser, water jet and plasma all produce teeth with tapered sides.

[youngfg]

This link may help, it shows how to draw sprockets.

[NC Cams]

More input but not in any order:

Blanked then stamped (IE bicycle sprockets)
Fine blanked (more precise stamped sprocket)
Cast iron then machined (automotive timing chain)
Powder metal formed then HIP'd (hot isostatic press) (automotive again)
HObbed and ground (perhaps most precise).

THe automotive stuff has the highest quality/cost ratio of anything you'll find because of precise timing requirements (emission legislation) and durability requirements.

[DennisCNC]

Here is the final product that I got, turned then teeth milled with a 1/8 end mill on my old school converted bridgeport. Can't ask for anything better for my project