Arri Anti-twist Drill guide for mafer/super clamp

A simple drill guide to add 3mm Arri style anti-twist holes to a standard mafer/super clamp.

Instructions:

• Attach the guide to the clamp with m5 screws. (10-32 screws required for Matthews clamps )
• Drill the 4x 3mm holes to about 4-5mm deep using a3mm bit.
• Remove the guide, clear debris from the holes

The other version “Mafer anti-twist drill guide v2”

Tools needed
   Drill
   No. 7 drill bit and 1/4-20 tapper tap
   1/4-20 bottom tap
   3mm drill bit
   Tap handle

Instructions:

• Ideally secure the clamp in a vise or just clamp it to secure surface.
• Align the guide on the clamp
• Drill out the center hole with the no. 7 drill bit. You want to go a bit over 1/4in deep. You can measure first and put a tab of tape to act as a depth marker. 
• Clear the chips and drill out the 4x 3mm holes. These need to be about 4 mm deep.
• Using the tappered 1/4-20 tap first (it's easier to align and keep perpendicular to the surface) Tap the 1/4-20 threads until it bottoms out. 
• Remove the tap and clear the chips.
• Repeat with the bottom tap so the threads will be deeper.
• Clear the chips and you're done.