Pilot Drilling

[johnjr]

When drilling large pens, does anyone use a pilot bit of any sort before running the big one through, or does everyone just go for it in one pass?

Thanks for the help!

 

[arjudy]

Usually a pilot hole will help the large bit remain true while drilling. It is especially helpful if the blank in question is on the small size. Also drilling on the lathe is much better than using a drill press if you have the equipment to do it.

 

[David M]

i use pilot hole befor the correct size on alot of pens . it help on acrylics not to be oversized from overheating / melting if going to fast.

 

[ribanett]

John,

I always use at least three drills when boring to 1/2" or so. If I think the blank might blow-out I use four. For most of my larger pens, the customer has pick the blank from my stock and I do not want to destroy it while drilling. I do all my drilling on the lathe.

 

[johnjr]

Thanks for the help! I just managed to blow apart an acrylic by running a 12.5mm drill bit into it without a pilot.....should have known better.......:frown:

 

[Lenny]

Just as important (IMO) is to allow extra length on your blank and stop short of "breaking through".... trim it back to the hole.

 

[bitshird]

I always start any hole in any material with a 60 degree center drill , usually either a # 3 or # 4, on acrylics remember there are different types, but drill in stages, small drill up to the final size, and watch out that you don't exit the end unless your in a collet chuck. cut long, mark the finish depth on your drill with a piece of tape.

 

[Sylvanite]

I often use a center bit to make a starter hole, but then I drill in one pass with the final drill bit size. I haven't had problems with overheating or blowout, even in acrylic.

Regards,
Eric

 

[cbatzi01]

I, too, use a centering bit, and drill in stages, usually, the pilot, a 1/4", 3/8", and then the final. on the big ones (churchill caps, etc), I might throw another bit.

Good luck!
Chris

 

[DurocShark]

I will start with a centering bit like this one, but I rarely step up on blanks. Careful slow drilling works as well and takes less time than careful slow drilling 3 or 4 times.

 

[Daniel]

I use a pilot hole, I often use a center bit as well. if I then drill in increments it is a decision I come to from a since that has developed from experience with various materials and how they drill. acrylic is different than wood. various woods are even different. be careful about drilling wood in to small increments as it is easy to end up with an out of round hole.