AirbotServices is proud to announce the world's lightest 2-axis brushless gimbal that carries a fullHD camera.
Here are some build pictures and comments:
Assembly of the cf masts.
First they are cut and sanded to shape, to fit together at a right angle (see above method described by Forrest):
It is tricky to get everything perfectly (or as perfectly as possible) aligned and/or at right angles:
Vuduglu was used (no screws, no brackets) to save weight. this is a toughened methyl methacrylate structural adhesive (like CA but reinforced with fibers, I guess). It is good for this application because it hardens and stays rigid. I would not replace the 3M 2216 glue by this one in a multicopter frame building application though, because you need to keep some vibration resistance and flexibility that you fnid in the 3M 2216 glue nut not as much in this one.
Another advantage of this glue, it start to harden in 10 minutes (while the 3M starts to harden in 90 minutes) and cures in 24h (while the 3M cures in a week).
Then the question is how to fix the two roll/pitch motors on these carbon fiber masts ? Answer : glue and 3D printing.
There are two 3D printed parts , one for the stator, one for the rotor. The stator piece is either glued on if you never need to use the motor for anything else later, or could be even screwed on if you need to get your motor back for antoher application later on.
The stator 3D printed mount is only used on the pitch motor. Indeed the stator of the roll motor will be screwed to the frame hilding the whole brushless gimbal ( a drone's frame for example or a handheld pole).
This piece was custom designed for the particular 1806 motors that are used and fixes itself by three little clips:
The second 3D printed part is what I call the motor cap. It covers the rotor bell of the motor. It holds without glue, nor screws ! Just a precise match, like a glove:
Then fitted on the motors:
Gluing the pitch motor must be done in such a way that the glue point must be precisely on top of the pitch mast, when the roll mast is in a vertical position. I used pens , tape to square everything as needed (yes pens remain useful in the internet age):
Glued pitch motor result after curing time:
You notice on that picture the 3D printed part on the stator of the pitch motor. The two little white marks represent the CG point where the motor center must be glued on.
Next , the full HD camera mount plate for the Mobius camera is glued on the rotor of the pitch motor:
This motor mount was built by Forrest Frantz using a balsa/carbon fiber sandwich. It makes it ultra light and ultra rigid.
Although screw holes were drilled, I did not use them as it is simply glued on the 3D printed cover, capping the motor's bell.
Now the trickiest part of all consists in fixing the roll motor. This is difficult to achieve because you need to be perfectly at right angles and find the right tangent on the round roll mast. You also need to find the center of gravity on the roll mast. So extensive use of squares are required, using gravity for perfect verticals:
The old masonry rope trick is used to find the roll CG.
And the final result:
Without the camera:
With the camera:
The weight here includes the motors, the servo cables, the velcro strips to hold the camera on ist mount plate. So it is a real all-in weight