Figuring Out The Modulus of a Gear

[EdK]

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

[DaveH]

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

DaveH

[EdK]

(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

[TomG]

Ed,

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

Tom

[EdK]

(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

[Sunset Machine]

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.