Ball-end cutter able to undercut

[chris_booth]

I'm having no luck finding a ball-end cut with a shank narrower than the ball-end and which can cut over 180 degrees.

They're sometimes used in making games boards for games that use marbles - such es e.g. chinese checkers - because thanks to the undercut you can machine a channel that the balls can't fall out of. See the attached image of a chinese checkers board. It might not be obvious, but the balls are stored in the channels and they can only be put back in or come out of the channel at one end.


38616.jpg

Anyone know where an appropriate cutter for making this type of channel can be bought?

[ron_moorehead]

Rockler has one.

http://www.rockler.com/product.cfm?page=5913

[chris_booth]

Thanks for that Ron...that's exactly the bit I'm after.

[srwtlc]

Here's some more...

http://eagleamerica.com/search.asp?s...cd2=1234051742

And a train track one that may work...

http://eagleamerica.com/train-track-bits/p/139-1775/