Need help with cutting gear hob

[cessna]

Hi, I am looking for the formula that determines how far the carriage is moved when cutting the hob rings. I know the module no. and depth of cut also have the od of the gear blank and number of teeth.
I have done this before with imperial sizes but cannot remember how far the carriage needs to move for each ring on the hob. The gear is a M 0.7, 24 tooth with the blank being 18.20 mm. This old brain just don't work the way she use to.
Thanks
Terry

 

[Swifty]

I think that it's the same as the circular pitch, which in your case is 2.199mm. I've made hobs before but I'm not able to access the information at the moment. Someone better agree or disagree with me before you commit yourself.

Here's a good data sheet that I use. http://www.micro-machine-shop.com/module_gear_data.pdf

Paul.

 

[Swifty]

This link verifies my thoughts. http://www.pic-design.com/PDF/PIC Design Training Issue 4 - Gear Racks.pdf

Paul.

 

[BaronJ]

Hi Guys,
This is a useful site. Lots of good data here.

http://www.hpcgears.com/n/left_menu/technical/technical.php

 

[cessna]

Thank you for the replies, saves me a lot of trial and error, thanks again.
Terry