On Tue, 1 Jan 2008 18:13:25 -0800 (PST), wrote:

Hi Ned I'd love some pics. re AT rollandelliott.com is my email.
You're right the aluminum extrusions are pre drilled so I just need to
tap them and you are also right in recommending the flutted taps. I
just never knew they exsisted!

The fixture in position for tapping. It mounts in the mill's t-slot
with flat head socket caps:
http://www.suscom-maine.net/~nsimmon...mFixture01.JPG

The 5/16 dowels fit in the extrusions t-slot and keep it aligned. The
screw with collar on the right clamps in the extrusion's t-slot.
http://www.suscom-maine.net/~nsimmon...mFixture02.JPG

The fixture in position on the mill table to cross drill for the
fastening sets.
http://www.suscom-maine.net/~nsimmon...mFixture03.JPG

The dowel pin locates the end of the extrusion to locate the cross
drilled hole.
http://www.suscom-maine.net/~nsimmon...mFixture04.JPG

A detail of the clamping screw. It's a socket set screw with a collar
loctited in place. The allen wrench for tightening is visible in the
first pic.
http://www.suscom-maine.net/~nsimmon...mFixture05.JPG


I guess my dilemna now is whether I should some how rig up my drill
press horizontally with a tapping unit or if I should get one of these
fancy handheld drilling units. I've already busted $50 worth of taps
so I'm a bit aprehensive about using a handheld tool that introduces
wobble and busting more. should that be a concern?

See my response to your other post.

--
Ned Simmons