Sérgio Domingos's Posts (3)

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DIY 3 Axis 360° Rotaion Brushless Gimbal


I just spotted on RCTimer's new items page a new brushless motor for gimbals - GBM5208-SR.

What's good about it is that instead of normal shaft it has a tube shaft with a 12.7mm hole, they include a Slip Ring of the same size with it, this makes it easy to rotate 360° in all axis, for most people 360° rotation on the yaw should be enough. Also, due to the big shaft/tube size, i suppose the motor should be stronger, with a shaft like this and those big bearings applying direct weight to the motor should be no problem.

I already build a 3 axis gimbal for my Canon EOS M with the 4114 motors, now it's time to start prototyping Version 2.

My plans are to make it rotate in all 3 axis using the slip rings, they have 12 wires, which is enough for my project.

Here are some details:

Pitch Axis:

IMU - 4 wires
IR Remote Switch - 3 wires
Video Out - 2 wires

- Sharing GND and 5V it will be reduced to 6 wires only.

Roll Axis:

Pitch Motor - 3 wires
IMU + IR + VID - 6 wires

- So i use 6 wires for the IMU, IR and VID, i still have 6 wires left for the pitch motor, the slip ring is rated at 2A per wire, with the 6 wires i'll connect them in pairs to the motor, which i believe should give enough power to the motor.

Yaw Axis:

- This axis will hold the Controller Board and an Sbus Decoder. I don't want to add more weight so i'll use power from Aircraft main Lipo.
- With the Sbus decoder i will only need to pass 4 wires to the aircraft, which are GND, 12V POWER, VIDEO, SBUS SIGNAL. 2 wires for Sbus and Video, which leaves 10 wires, 5 wires for GND and another 5 for 12V should be ok i think.
- Yaw Motor and Roll Motor don't need the slip ring, since their leads are in the same axis, so i just can connect them directly to the Controller Board.

I can't wait to start this project, what do you guys think? Cheers!

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Hexacopter Project


Hi guys, i want to share my Hexacopter Project.

I designed all the frame parts and cut them out of 2mm carbon fiber in a cnc machine, this is still a prototype, I need to fix a lot of mistakes in a second revision of the frame.










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ArduCopter Quad Carbon Frame DIY Build

Hi there,

my first post here :) Just want to share this build log of my first DIY quadcopter frame in carbon fiber.


- APM with GPS and Magnetometer
- 25cm Arms
- 54cm from Motor to Motor
- 18Amp HobbyWing ESC
- 750kv Motors
- 10x4.5 Props
- Turnigy nanotech 2200mha 25-50c


- HobbyKing camera with mount
- Fatshark 5.8Ghz 100mw video transmiter


- 640gr only the frame, motors and escs
- 980gr Total with the Video transmitter (not in the pictures)

Is this a good weight for this frame size and config?

About the build

I used CF 1.5mm sheet and CF tubes with 13mm diameter, to mount the motors i drilled the holes directly in the CF tube and used some plastic prop adapters to reduce vibrations. I also used some thin double side foam between the arms and top plate this way the arms will not be in direct contact with the CF plate, don't know if it helps or not. To hold the APM board the the frame i used the same double sided foam, i used 2 pieces on top of each other to give it a bit more height.

I intend to use this frame at first for some FPV, i used 8mm CF square tubes to make a camera mount, it looks pretty cool :)

I could save some grams in the wiring, but in this first step i decided to keep the wires in its original length for later changes, right now its a mess of wires between the 2 main center plates.  

Some things i noticed after the build and 2 short test flights:

I thought that it was a good idea to drill the holes in the CF tubes and mount motors directly on it, actually the tubes can handle the screws even very tighten, they didn't crack, but its hard to get perfect hole alignment without proper tools. I used an aluminum profile 15x15mm, inside diameter was 13mm exactly the outer diameter of the CF tubes, i easily drilled the holes in the aluminum profile to serve as guide and inserted the CF tubes inside. It worked pretty well, but the inclination was not so good, it's hardly noticed but motors have some minimum inclination.

I'm afraid this inclination error will affect the stability, anyone has something to say about this? I'm thinking in changing the arms to aluminum square profiles or get some mounts like Heli tail booms, it would be easy to adjust inclination.

I didn't tune PID's yet, so first flights were a bit unstable, also i wonder if having the plates stacks too high can affect the stability as well.

Also the arms look nice when short close to the motors, but will be a problem if it crashes, and i'm sure it will :(

Here are some pics of the build, Cheers!




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