On 6/22/2014 4:10 PM, Gunner Asch wrote:
On Sun, 22 Jun 2014 14:26:42 -0400, Tom Gardner Mars@Tacks wrote:

On 6/22/2014 2:18 PM, Lloyd E. Sponenburgh wrote:
Tom Gardner Mars@Tacks fired this volley in news:r-
:

The holes don't have to be burr-free but I would like to
minimize the burrs without any secondary operations.

Tom, you can't eliminate the "breakout" burrs. Use the fastest feed you
can to get a clean chip, and you will almost completely eliminate the
burrs at the top of the hole.

Son, de-burring is part of the process. Unless you put a 'waste sheet'
under the material, and drill into it past the shoulder of the bit,
you're going to get burrs. And then only if it's clamped so tight to the
work that there's not a chance of pushing a burr between the sheets.

LLoyd



A sacrificial piece of hardwood be sufficient? How about a drill
bushing under the tube?

Bushing still wont help. That last burr is the result the metal being
torn away from the mass by the downward pressure.

The only way you are going to be burr free is to use a deburring tool.
Which is really not a big deal in Aluminum.

http://www.vargus.com/Shaviv/

http://www.noga.com/

http://www.mscdirect.com/browse/tn/A...navid=12100123

etc etc

I have Vargus, and Noga of variouis kinds, from hole to sheet
deburring....and they all work great once you get the hang of em.


Gunner

"Libertarianism IS fascism... Fascism is corporate government – a Libertarian’s wet dream"
Tala Brandeis
Owner at Tala Brandeis Associates"



No time for another operation and a smal burr is OK, I just want it minimum.