Ok.........., I have purchased a drill press, set up the fence to drill rings, used a 1/4" bit to center the hole, and using a 1/2" forstner bit, drilled the hole.
After drilling, I pick up the ring ( rubberized cork )and look at it, and the hole is obviously not centered in the ring.

why......???

bent drill bits......???
mistake in set up...???
need cork clamp....???
need pilot drill bits....???
rings dont have centered 1/4" hole....???
shouldn't worry about it since the rings will be glued and shaped on a mandrel...???

forstner bit (Sears) does an excellent job with a nice clean hole and no chipping or rear blowout @ 3600 R's, using a backup piece of 1x4.
I have scoured all of the archive's on drilling cork rings, would like your opinions and observations.

thank you, pb

What do you use to hold the rings? Did you check to be sure the 1/4" hole was centered? How far off center are they with the 1/2" hole? If they're only off a little, it may not make any difference in the long run although it will feel pretty strange with you shape it on a lathe, you will have to make it concentric first. I've used the Flex Coat pilot drill bits on cork grip after they've been shaped and they work pretty slick, but a Forstner bit should be fine as long as it's centered.

I held the rings up against the fence endstop and fence backstop with my fingers....and this is not the way to do it, safety wise. I ordered a back issue of Rodmaker that has the directions for building a cork ring clamp....

How do you go about checking the 1/4" ring to see if it is centered.......I didn't measure with my calipers if that is what you mean. But, as I mentioned, I used a 1/4" bit and adfjusted the fence so that the bit was centered in the ring.

The holes are just a little off center......but enough to see that it is off center.

After posting this, I went back to the drill press owners manual and saw that I have not squared the table to the head.....as yet......will have to bring a square from home to check this.

thanks for the reply Gerry, pb

Save yourself a lot of time/trouble and spring for Flexcoat pilot bits [flexcoat.com] Pick them up from just about any vendor on the left. They're fool proof!! Easy to just hold the ring with fingers on the drill press and go for it!

Mike



Edited 1 time(s). Last edit at 06/01/2005 03:15PM by Mike Barkley.