On Tue, 09 Sep 2014 12:27:28 -0700, Bob La Londe wrote:

I routinely need to drill a bunch of holes in aluminum bar stock. My
drill press does an adequate job, but when it punches through it leaves
an expected ridge which I clean up using a reamer in my air drill. The
issue is in order to make sure every hole drills pretty straight I have
to flip the plate over after each hole and back ream the ridge. One
idea I have had is to bolt a couple pieces of flat to the table so I can
atleast drill all the holes that are in the same row before I have to do
a cleanup on the back. Any other suggestions?

Make a channel as wide as the bar, with a slot a bit wider than the
holes. The bar will rest on the shoulders of the channel, and the burr
will (if everything's the right size) stay inside the bounds of the slot.

Drill, drill, drill, deburr, deburr, deburr.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com