Internal Gear Cutting

[Hellbringer]

Hi,
I have figured out how to cut a normal gear but the project i am working on requires a internal spur gear. how would you go about cutting a internal spur gear.

thanks
Mike

[RICHARD ZASTROW]

Normally, internal gears are cut on a gear shaper. The cutting tools are made to cut the internal tooth form.

An internal gear can also be produced on a mill with a shaper attachment and a rotary table; a horizontal shaper with a rotary table mounted vertically; a vertical shaper/slotter or? Could also be produced on a wire EDM.

Be sure you know what the correct INTERNAL gear tooth form is. Your tool must match that form as the tool determines the form.

Dick Z

[Andre' B]

In addition to the above.
You can also rig an indexing disk to a lathe spindle and wheel the carriage in and out like a shaper.
Or if you are real patient you could layout the gear teeth, use a drill press and a scroll saw to rough it out then a die filing machine to finish to the line. It will get you something that looks like a gear but would only be usefull for slow speed crude power transmission.

[cracker]

http://www.google.com/url?q=http://w...nU7xy_q6qJ19BA

you can do this on a lathe (it's called a rotary broach made in michigan)

or use a "Polikely" check the videos out on a mill

http://www.tpsintl.com/poliangolar.h...FQkMDQod7Bsxhw

[gopal6601]

Thanks for sharing this great information with us.

[rowbare]

Have you looked at Gearotic?

bob

[wwendorf]

Here is the email of a guy who makes a rotary broach holder that is about 1/3rd the cost of Slater Tools holder. cmgmachining@juno.com

You still need to buy a rotary broach from Slater, but you can save some money on the holder.

I will warn you tho, you will need to have a LOT of force at your disposal to force the broach into your tool. I'm sure a Tormach would do it, but I do know that my old Southbend Magnaturn didn't have anywhere near enough force to do it.

Wade