Drilling Pen Blanks

[John Miriello]

I know this has likely been addressed before but I would like to get some fresh ideas on the topic.

Using acrylics and corian as the examples, I consistently get blow out when getting near the bottom of the blank. I am trying to temper my technique with adjust the speed of the drill press and the feed rate. Perhaps I should try putting the blank in the lathe chuck and try drilling with a Jacobs chuck in the other.

I would really appreciate any thoughts from the seasoned veterans here to get me through this. I am wasting more than I am turning.

Thanks folks.

[Dario Octaviano]

Slow the drill press a bit, make sure the bit is sharp and clear it regularly especially as you go deeper.

What works for me is cutting the blank longer and STOP before the drill exits the blank, cut the excess after and you should have a through hole.

If the blank length won't permit above, try placing a piece of wood right next to the exit hole. I also drill a smaller hole at the exit/other end first. having that as exit for shavings releaves pressure.

Make sure the vise is holding the piece well so it won't grab it up as it exits.

Hope these helps

[Bob Noles]

Slow and easy is the best advice I was given and I have yet to blow a blank. Sharp bits, small light passes removing the bit often to clear the chips and allow the bit to cool a few seconds between passes. Use very light pressure on the press and take your time.

Pretty much repeating what Dario has explained. I think the largest problem in my opinion is pressure and rush to get it done. Just let the bit do the work and stop trying to help it so much.

[JOHN VITOSKY]

An other thing Ive learned really helps is justa drop or two of water every other pass or so down the hole and I havent had one blow out since doing so. Cools and lubes the bit also.

[Dick Strauss]

John,
Here are a few good charts with drilling speeds. Pay close attention to all tips in the first link.

http://sawdustmaking.com/Free%20Charts/Bit%20Speed.pdf

http://www.woodsmith.com/files/issues/137/bit-speed-chart.pdf

Good luck,
Dick

[John Miriello]

Thanks one and all. Speed seems to be my biggest problem. Funny how the wife says the same thing when we are in the car. Hmmm.

[RichMagnone]

Another tip: if you hear the drill bit squeeking, it is getting too hot. Stop drilling and let things cool off a bit.

[Ken Salisbury]

What works for me is cutting the blank longer and STOP before the drill exits the blank, cut the excess after and you should have a through hole.



I have used this method for years.