Here is a nice little project that passed testing phase with success on quite a few shoots this year. It's a focus ring holder that can hold five WCU-4, HI-5 or Cmotion CPRO rings. It now also has a optionnal NP-FM500H battery side holder (a LBP-3500 version is coming as soon as I get my hands on a battery for a day). It can be attached by a couple of 1/4" treads location or by the v-lock system in the back. (I use it with a standard v-lock clamp like this one : http://t.ly/c-mj)
new version with new writings : ARRI / Cmotion / Preston 😉
Notes : you will need, for the main unit : 2x 1/4-20"x8mm treaded inserts 5x M3x4mm treaded inserts for the side battery holder : 1x M3x4mm treaded inserts 3x M3x6mm Flat Countersunk Head Bolt Screws for the v-mount : 3x M3x6mm Socket Cap Head Screw Bolt
Warning : For best mecanical resistance, you need to print the main unit on it's side so that the 3D printed layers are vertical once the unit is in use.