This mounting system attaches the twin flash heads of the Canon MT-24EX macro flash to your lens' tripod collar using 1/2" Loc-Line tubing to form the arms.

This allows a connection that is rigid enough that it'll stay exactly where you put it, but is also easy to adjust to put your flash exactly where you need it.

One of the main goals of this design is to limit the degrees of freedom of the system. I got fed up with third-party flash arms which would twist and loosen on their mount just when you didn't want them to, and allowed the flash heads to spin on their ballhead mounts too. This design uses anti-twist mounts on both the lens and the flash ends of the connection, so that the only thing that can move is the arms themselves and the adjustment built-in to the MT-24EX. Perfect!

I've designed an anti-twist mount to suit the Sigma TS-21 lens collar. That Sigma collar is found on the following Sigma lenses:

• APO 70-200 / 2.8 EX DG OS HSM
• APO 70-200 / 2.8 EX DG MACRO HSM
• APO 70-200 / 2.8 II EX DG MACRO HSM
• APO 50-150 / 2.8 EX DC OS HSM
• APO 100-300 / 4 EX DG HSM
• APO 300 / 2.8 EX DG HSM
• MACRO APO 150 / 2.8 EX DG HSM
• MACRO APO 150 / 2.8 EX DG OS HSM
• MACRO APO 180 / 3.5 EX DG HSM
• MACRO APO 180 / 2.8 EX DG OS HSM

I've also designed a mount which fits an aftermarket replacement for the TS-21, the iShoot SM720, and this is the collar shown in most of the photos above. Because this collar has more than one screwhole on its foot, a much sturdier and more compact anti-twist design is possible.

For a version of this mount with no anti-twist features, designed to be mounted to the bottom of a camera, see this design instead: https://www.thingiverse.com/thing:4652788

The super long extension tube shown in the photos above can be seen here: https://www.thingiverse.com/thing:3761957

You can find my design for MT-24EX diffusers here: https://www.thingiverse.com/thing:3844481