phuffstatler

My Feedback: (20)

I'm talking 1/16" to 1/4" thicknesses, for the most part. I'd like to the cut to be pretty darned clean, needing minimal dressing. In other words, I don't want to create a 2.5 inch hole with 2 inch holesaw...


I've got a drill press and hand drill here in the shop... Some of the pieces are already mounted, so I would have to use a hand drill there...

Thanks!

phil in austin

CurtD

My Feedback: (1)

I've had very good luck cutting large holes in balsa using Forstner bits. About the largest I've cut is 1.5".They get more expensive as the diameter goes up, of course, but for balsa, lite ply and thinner birch ply, the cheap Forstner bits you can get at Home Depot or Lowe's work just fine.

Forstner bits are best used in a drill press to keep them aligned properly and always use a wood backer board under the wood you're drilling through.

Rodney

I've had good luck just using the proper sized brass or aluminum tubing. I sharpen the inside edges with a stone or file and turn the tube by hand. I hope you realize though, that you gain very little weight reduction doing this and you can weaken the structure excessivly if you misplace a hole or two. Except for athetics, lightining holes are essentially useless for that purpose.

CafeenMan

I do it Rodney's way. Forstner bits are kind of expensive.

Also, you can draw the circle, cut it undersize with a scroll saw and then use a sanding drum on a Dremel. With a little practice it will be so close you won't know it wasn't drilled.

Tony Hallo

I've found that a hole saw when used at the maximum speed on my drill press does a pretty good job, about 3500 rpm, use light feed of course. If possible I drill from both sides.

GW-inactive

My Feedback: (4)

Lowes sells a circle cuttter that mounts in a drill press( i believe). Makes a very clean cut ,I hear, from reputable sources. About $8 cost . I plan on picking one up next trip.

phuffstatler

My Feedback: (20)

Great ideas, gentlemen! Thank you all...

I'm going to look for that circle cutter, and I'm probably going to get some forstner bits as well, since there are other non-aviation projects coming into my schedule...


Thanks again!
phil in austin

rogerswin

My Feedback: (2)

Use a 12-gauge shotgun (up real close)!!

I truly hope you know I'm joking?!

vtol_guy

hmmm....sounds reasonable

pjwright

Of course you could always look on ebay for cheap-o Forstner bits. For example:
http://cgi.*********/ws/eBayISAPI.dl...category=20795
Typically $20 plus $10 shipping.
I haven't seen anything this cheap at Home Depot...
pj