Ideas on Gear Cutting.

[mws]

So here's another one of my long posts to draw on some of the experience others may have. I want to make some gear cutters and ultimately, some gears. The “button” method of profiling a gear cutter seems the most practical. Albeit only an approximation of the addendum profile. I have found some tables for determining it's diameter. But very little information about how to apply the button to the cutter blank to determine deddendum depth or root width for a given pitch. Any ideas?



Aside from generating an involute profile with a hob, or some cutter synchronized to the rotating blank (like a Fellows Gear Shaper), this button method seems the most practical. But I'm open to any other suggestions. Good gear cutting sets seem very expensive given I don't know what size gears I may decide to make and I have given up buying Chinese cutting tools. At least, tooling that can't easily be resharpened.



Mark

 

[Reeltor]

Mark,

I am inexperienced in making gears, can you explain what this "Button" method is? I agree, Involute cutter sets are expensive and are better left to "buy as needed". I think MrPete222 aka Tubal Cain has some videos where he cuts gears using a fly cutter and a HSS bit that he ground to match the gear profile.

 

[Doubleeboy]

might want to Check out the gear cutting video by Jose Rodriguez, very easy to make your own hob. Little Machine Shop sells the video. All the work can be done on table top machines if that is all one has. Highly recommended!!!

 

[Billh50]

I know there are a few articles out there for the button method. I have a couple from older Model Engineer. Mikes workshop has some info.
http://mikesworkshop.weebly.com/designing-gear-cutters.html

 

[mws]

Thanks I'll check those out. I also found this which I thought was a nice write-up. The more I see about using hobs to generate the profile the more I like it.
http://david.rysdam.org/machining/gears.html

 

[Hawkeye]

Chapter 12 of Workshop Practice Series #17, Gears and Gear Cutting, gives a good introduction to disk-type gear cutters. Interesting reading, if nothing else.

 

[mws]

Hawkeye,
Thanks for the tip on Workshop Practice #17. It seems, thanks to SCRIBD, I'm accumulating an excellent library on Machining. The chapter on making cutters shows clearly the geometric relationships of the circular button to the involute profile. While it doesn't give a formulaic solution for all pitch and pressure angles, I think I can develop that now. I prefer equations to tables, but YMMV. But knowing that the button radius equals the tangential radius of the involute curve from pitch circle to base circle answered all my questions. Thanks again.

Mark

 

[Bill Gruby]

Mark:
Much info here. Book #17 is extremely easy to follow. I use it all the time.

http://mikesworkshop.weebly.com/designing-gear-cutters.html

"Billy G"