Anyone have any suggestions for ultra-high quality drill bits that will drill into soft woods (balsa) without ripping the wood...especially larger sizes? Forstner bits, etc?

I hate sloppy 1/4 inch holes in balsa and want to improve my quality of hole!

Mike

A lot of guys just use brass tubing to 'drill' balsa.

I don't know of any bits that help but I was thinking of hardening the balsa with ca before drilling. If the peice has not been installed you can sandwich between hard wood or plywood although lining up the spot to be drilled can be a problem.

You can use brad points http://www.woodcraft.com/Product/200...Point-Bit.aspx or forsner bits. Always back up your balsa with another piece of wood under it for clean holes.

Aaron D.

Nothing drills balsa like a sharpened piece of brass tubing. Sharpen the inside edge of the tube with a dremel grinder and it'll give you razor clean holes. But be careful. It'll make razor clean holes in fingers too.

For larger sizes I cut it undersize by hand with an X-acto and then use a dremel sanding drum to finish.

Dave

Brass tube is best, but finding center is a PITA, I harden the area with thin CA and use frostner bits, Porter cable makes them and the home depot sells a set for like 20 bucks. Get a set, you'll use them for almost every hole drilled in wood. Start easy, bore smooth and leave almost not splintering on the back side of the wood.

Forscner are awesome. You can even drill a hole just off-set from a previous hole without destroying the wood. They are great but be sure to get good quality and keep them razor sharp...

The best hole in balsa though is done with a brass tube. I use a #11 razor to sharpen the inside of the brass tube.

Yup, just put the brass tube in a drill and spin it at slow speed while sharpening it with the #11 from the inside, the frostner bits are great thou, no more ugly triangle shaped holes you sometimes get from a standard drill bit in soft balsa.

I may have missed it, but the brad points work their best when there is a piece of harder wood behind the balsa. We removed some 10 windows of planattion shutters from our house over the last three years. The wood is either very straight grain pine or Bass wood. I saves all of the 3 and 4 quarter wood and I have some pieces of it that look like swiss cheese from backiing the drilling of the balsa and lite ply. You don't need to harden the wood first either.

I also use a 1/8" brad point for drilling Robart hinge point sockets.

I picked up a set of Blank and Decker brad point drills, 1/16 through 3/8" from one of their"factory outlet" stores a few years back. I use them only for balsa and they really hold upwell and cut anice smooth hole.

Thebrass tubing drills could be upgraded, using Stainless steel tubingand mounting a pilot drill, maybe 3/32" to center it and keep it going straingt. If you limit your self to a 1/2" depth there would be little that couldn't be handled with that drill for our purposes.

Remember, with soft material like balsa, high speed on the drill with a very fine feed rate will give you your best cut. Most problems with trying to drill anything very thin is that the drill grabs a pulls through the bottom side, riping and tearing the surface. Dull drills and slow RPMs agravate this problem.

There are a number of "step Drills" on the market for drilling thin sheet metal. They may make a good drill for balsa as the twist drill pull though is a problem for sheet metal also. The question would be, what is the step depth. If it is only for say 20 ga metal, it wouldn't be much use for 1/8" balsa. Worth looking into though.

Don

Don

Yes, unibits work too, but they have only one open area for cutting, so they tend to tear as they cut.

High speed bits in a rotary tool seems to work for me. Make sure they are sharp or it will tear.

Thats the best info in this whole thread.

Unfortuanatly it's hard to get enough rpm and steady hand to do it right. Ergo the tube method. I've even cut sipes into the tubing to make it clear the dust better.