MetalworkingFun Forum

How does one figure out the modulus of a spur gear? I'm wondering what the modulus of the change gears of my lathe are.

Thanks,
Ed

Ed,
See if this helps http://www.micro-machine-shop.com/module_gear_data.pdf

DaveH

(09-24-2012, 06:18 PM)DaveH Wrote: [ -> ]Ed,
See if this helps http://www.micro-machine-shop.com/module_gear_data.pdf

DaveH

Thanks Dave. I'll have to read that a few times before I have a chance of figuring out what all of that math means.

Ed

Ed,

I believe it's just the pitch diameter of the gear divided by the number of teeth.

Tom

(09-24-2012, 06:28 PM)TomG Wrote: [ -> ]Ed,

I believe it's just the pitch diameter of the gear divided by the number of teeth.

Tom

Thanks Tom. That I can work with. I'm sure the lathe change gears are metric but didn't know how to figure out the modulus.

Ed

And to confuse us all, DP gears are just the opposite... teeth/PD

An edit to add a possibly more useful tidbit::: (Outside Diameter) / (Number of Teeth + 2) = Module
Similarly, you'd reverse divisor/quotient for DP gears.