Mobius gimbal (2 axis) for 22mm motors and H frame

thingiverse

Preface This gimbal was based upon two other sources, of which unfortunately the source files are not available and both authors did not reply to my inquiries. http://www.thingiverse.com/thing:216558 Here, the holder which turbi uploaded (other than shown in the pictures!), presses on the "power" button of the Mobius. Also, it's very difficult to print as the "roof" part has extremely thin walls. Overall, it looks very nice on his renderings, but was not designed for printing. http://www.thingiverse.com/thing:332566 Here, the holder looks very nice, but is, unfortunately, is also not easy to print. When printing laid horizontally (not vertically as in the original images), some parts are in the air. Also, particularly without cooling fan, the small screw holes in the "tower" will be a mushy mess. Turbi's design was created for 28mm motors, which are available through hobbyking. The lightest ones I could find were ~32g 2206-140KV, which is quite a lot. I wanted to have a gimbal with smaller and even lighter motors 1807-340KV (beware of their stiff cables though, see my photographs for suggested motor mounting position and cable guidance). My overall weight is 154g with cam, controller board and cables, which seems to be extremely good compared to the metal gimbals you can buy off ebay or hobbyking. Changes to original sources With the source STLs, it seems impossible to import the meshes with sketchup or Solidworks: both programs have "repair-on-open", which breakes a lot of faces. So I used OpenSCAD to augment the existing meshes and export a new complete STL. Worked fine. The inner diameters of both motor holders were changed from 28mm to 22mm. In order to balance the gimbal, I extended the Y axis holder arm a few mm. The X shaped vibration dampener holder had too large holes. I reduced their diameter as well. Just measure the diameters you have and adapt if necessary. In the cam holder I strengthened the 2 small flexible nipple arms that slide into the screw holes of the cam. Also, I removed the curves from the mounting position of that holder and replaced it with a flat ugly box. Way easier to print and hopefully more stable. Tools and Materials Small cutter knife M2.5 screws with nuts and washers (for motors) maybe M2 screws with nuts and washers (the screw holes are very small) PLA and ABS in your desired color. Natural / Transparent seems to be the strongest. Four rubber vibration bumpers Notes Use the mirrored cam holder in order to have the screw attachments at the respective bottoms (so they don't get in the way while rotation takes place). In case you have a different frame, you'd need to design your own part of the top holder. Use a 8mm suare pillar to connect it to the top X shaped vibration dampener. Also, see the pictures on how the StoRM32 is attached to the whole frame and how, in particular, the wires are guided. This setup may look strange but provides enough flexibility for all positions the camera can be moved into. Print Settings Printer: Custom Prusa i3 (portal version) Rafts: No Supports: No Resolution: 0.2 Infill: 25% Notes: You must use ABS for everything but the two X shaped vibration dampeners and the adapter for the H frame, since the motors get very hot and PLA just softens up. I printed on a durable print surface by 3D prima and used white ABS / PLA. Remember to heat the bed to 105-110°C for ABS. What to print 1x holder_top (PLA/ABS) 2x support_x (PLA/ABS) in the version you need 1x bras_suspension (ABS) 1x roll_arm (ABS) in the version you need 1x pitch_arm (ABS) in the version you need 1x mobius_mount_mirrored (ABS)