Monday, September 7, 2015

Mill Table Strap Clamps and T-nuts

Everywhere I go where there is a milling machine, there is always a set of strap clamps and T-slot nuts nearby.  I didn't realize the importance of this until I actually wanted to clamp something that wouldn't fit in the vise.  Basically, without strap clamps, you're missing out on 90% of clamping potential!
A strap clamp works by securing a clamp with a threaded rod to a T shaped nut in the corresponding shaped slot in the machine table.  The back support for the clamp is usually provided by a staircase shaped wedge and stair shaped cuts in the back of the clamp, but that's unnecessarily complicated to make for my application.  Instead, I decided to just tap a 5/16" hole in the back of the clamp and use carriage bolts to adjust the height range.  The shim is so I don't mess up the table.
strap clamp diagram