I am using a method that I invented I termed:  Self threading square tube insert method. Whats so cool about this is it combines fairly easy cuts of aluminum that pretty much anyone can do with a band saw, hand saw or rusty pocket knife… Well not the last one and I don’t suggest you try it.  But is very cool.  Basically its all in the spacing of the 4 holes that were laser cut that the aluminum sits below.  Its a very tight squeeze which allows the screws to “self thread” inside the square tube’s inside.  Hence the name.  Not super witty but it describes it nicely.   Comments, questions or concerns always welcome.  Next thing to make is the collet holder.

Here is the final results:
http://www.thingiverse.com/thing:1393

Thingiverse Links as always here:
http://www.thingiverse.com/thing:1393

However, My metal cutting table has clamping T’s that little bits of metal would fall down into and become very much of a pain to clean.  So I decided to fab a part in google sketchup for the T slots to help extract the junk.  So a few quick measurements with my digital caliper and I was good to go.

Thingiverse Part Here: http://www.thingiverse.com/thing:1372

Here is the final product: