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Pushing the envelope - a BIG gear horizontally on the Taig mill

Posted: Sun Apr 13, 2014 7:04 pm
by Stephen Fornelius
I'm doing a sprocket for a #25 chain for a clock I'm designing.  The issue is that the specifications of the chain establish the diameter of the sprocket.  For example, an 84 tooth gear is about 3 inches, and 84 tooth sprocket is 6 7/8". 

With the advice of Art, and products from Wildhorse Enterprises to extend the y-axis, I was able to cut a gear 6 7/8" diameter on a Sherline cnc rotary table horizontally.  This is about 1 inch beyond the standard table envelope.

This was impossible to do in a 4th axis because I would have had to jack up the rotary table about 2" and lose rigidity, the rotary table would have been offset too far forward, and I would have needed some significant backup plates to prevent distortion if a fly cutter was used. Plus I need more experience doing something like this of course.


Re: Pushing the envelope - a BIG gear horizontally on the Taig mill

Posted: Mon Apr 14, 2014 12:20 am
by ArtF
Stephen:

Glad to hear it worked out..Large gears are always difficult for us Home hobby guys...

Art

Re: Pushing the envelope - a BIG gear horizontally on the Taig mill

Posted: Mon Apr 14, 2014 5:20 am
by JustinO
"Stay within the lines."

Stretching and extending the limits is great fun -- I've had parts on my Sherline lathe that weighed more than the lathe.