[sdiy] Machining aluminum, part deux

[Dave Magnuson]

At 10:23 AM 4/18/02 -0600, Kenneth Martinez wrote:
>Just drilled my first aluminum panel - worked fine with my bargain-store
>drill bit set, once I got a small drill press (only $40).  No more
>hand-drilling for me; and no need to make a small hole first & enlarge,
>etc


I think this might prematurely wear your bits.  I realize that aluminum is
fairly soft, but heat is the number one killer of drill bits.  I'd still
use perhaps an 1/8" or 3/16" pilot hole before going to the full sized
hole... it just has the bit doing a little less work, and stays cooler.

Obviously, drill RPM and feeding speed are also factors in heat build up.
Likewise, don't drill 40 holes in rapid succession... let your bits cool
off ocassionally.

Personally, I center punch, drill a 1/8" pilot hole, and then use a
step-drill or "Uni-bit" to enlarge to full size.  Gentle pressure on the
drill, and allowing it to cool every 5 or 6 holes.  I've had the same $30
Uni-bit for 3 years and it still cuts like new (I also use it on 16ga steel
and light gauge stainless).  An added benefit: after the hole is the
correct size, you can use the next sized step to chamfer the edge of the
hole...  Saves a lot of time.

Dave Magnuson

Resonant Frequency:
resfreq at hoohahrecords.com
http://www.hoohahrecords.com/resfreq/index.html