Ball board.

[ohio ramrod]

As a machinist/tool and die maker and one who has made over 100 ball boards I find it interesting that you posted: " using a 1/2 dril bit with a 490 ball and ten thousands patch the balls would fall out. " I assume you had a hole well over .500. A true 500 hole would give you ten thousands compression ( .490 Plus .010 plus .010 ). I find that if the drill bits are properly sharpened they will actuall drill a hole approximately .005 to .010 undersized in wood due to the wood fibers actually compressing away from the bits and then swelling back into the hole.This happens less with fostner bits than twist bits. Spade wood bits are known to chatter and cut well oversised. So I assume you used a spade type drill to have the balls fall out. I drill my ball boards to caliber then use a tapered reamer to open them up to desired fit for the patch and ball that will be used.This makes the boards easy to load,unload, and keeps the balls secure. And after all we don't want to lose our balls!

 

[Ketchakah]

I never thought of that.... Yes i did use a spade bit. thats a really good thought. ill have to try a regular type twist drill.
Thanks. :thumbsup:

 

[RJL]

I've always used a 1/2" spade bit to make my blocks. never had a problem losing balls in fact their quite snug with a .015 patch .490 ball. i drill one side halfway through then flip it over and finish the hole with the pilot from the other side.i make my blocks about 1/4" thick so the ball is easier to center in the bore. imho.

 

[bwhoffman]

these are for .50, I use a brad boint bit.
I also use a tapered reamer nowadays and that works well.