Cutting internal gears

[Johann]

Is there a method to cut internal gears without a shaper ? I have a lathe & milling machine with dividing head to work on ?

 

[///]

I have seen people use lathes and milling machines as shapers, not ideal obviously, but doable.
Maybe a press and a broach made to the right form?

[ame]http://www.youtube.com/watch?v=qSnWINtDAfs[/ame]

 

[Jasonb]

I've done it like in the video, really depends on how accurate a profile you need, for a slow steam engine its fine, may not be ideal for 20,000rpm.

 

[Mechanicboy]

Or you can make a gearwheel in silversteel and use it as a broaching tool to make internal gear with the hydraulic press.

 

[chrsbrbnk]

I think I would try it with an index table and a cutter in a milling machine spindle , lock the spindle with the brake , maybe turn the power off, a cutter in the quill thats the shape of a single tooth in a borring bar. then its just several repeated strokes of the quill feeding in with the mill table like .005 to .01 a cut , use like sulpherized oil as a cutting fluid back it up to zero each time and index and repeat alot
We used to make square corners and those light bulb sockets on the back of old car dashes dies that way. then they invented EDM's

 

[Swifty]

I've done a lot of square corner broaching in milling machines, always a lot of hard work. Take a slightly too large cut and you come to a sudden stop. Perhaps if you are doing it in a milling machine with a rotary table you can rough it out with a milling cutter first.

Paul.

 

[Johann]

Thanks guys. Seems the lathe method can work. I was thinking of making an attachment clamping on the chuck to serve as a dividing mechanism, didn't even think of using the gear on the main shaft as a dividing mechanism ! Show that the complicated path is not always the best path - thanks for excellent advice. There is a saying that says 'Common sense is something thats not so common' Ha ha