(Top posted because you wouldn't have wanted to scroll down for my two line
response anyhow...)

Any people wonder why I asked here about this process. Excellent, and well
"aimed" response that is much appreciated!

Regards,
Joe Agro, Jr.
(800) 871-5022
(908) 542-0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R


wrote in message
oups.com...
Hello Joe;

I'm glad to help! I'm a veteran mechanical engineer, machinist, and
fabricator, as well as a woodworker, so I'm quite familiar with the
types of machines that you offer.

One of the bigger manufacturers of MDF is Sierra Pine
(www.sierrapine.com). Check out their website for technical info on the
various grades of MDF.

In my shop, I mostly use MDF for templates, fixtures and light duty
tooling. Sierra Pine's "standard" MDF, which weighs 48 lbs/cu.ft., is
my favorite. It drills and machines beautifully. The various Lite
grades, at around 30-35 lbs/cu.ft. are much more difficult to work
with. The low-emission Lite grade is the worst for drilling. There
seems to be so little resin holding the core together, that as soon as
you pierce the skin, it's like drilling a stack of newspaper. But the
low-emission lite grades are popular with furniture factories because
of the lighter product weight and reduced employee health hazards. So,
that's probably what many of your customers are using.

I would guess that the solution to production drilling it is mostly in
the fixturing. The key would be to tightly clamp the MDF between two
flat-faced drill guide bushings, to prevent the surface skins on either
side from flaring, which then allows the inner layers to rip. A brad
point or even a reverse-ground drill bit would probably be the best,
with a fast spiral and very sharp outer flutes. If the MDF is properly
clamped and supported, you can probably run a very fast feed profile.
The trick will be in clearing the swarf out of the drill bit and the
bushings.

Bruce Johnson
Johnson's Extremely Strange Musical Instrument Co.
Burbank, CA