Newbie needs help in RC system design

[Deeber]

Hi all,

I'm in over my head, but hoping someone can shed some light on how I can set up a RC system to achieve what I need.

Basically, I need 4 motors (each with its own speed controller) to operate together and individually. For ease of discussion, I'll name them A, B, C and D.

I don't care how many channels or components I need, I'll buy whatever it takes to make this work. I'm sure I can do it with a combination of mixers, but just don't know how.

OK, here's what I need it to do:

1. Stick 1 (up/down) on the transmitter = increase/decrease speed of all 4 motors, together.
2. Stick 1 (left/right) = Increase speed of motors A & C while decreasing speed of motors B & D
3. Stick 2 (Up) = Increase motor A and decrease motor C
4. Stick 2 (Down) = Decrease motor A and increase motor C
5. Stick 2 (Left) = Increase motor B and decrease motor D
6. Stick 2 (Right) = Decrease motor B and increase motor D

Any thoughts?

Thanks guys.

Darren

[jeffs555]

Darren.
Haven't tried it, but you should be able to do it with 3 off the shelf V-tail mixers like the GWS, but there are some caveats that I will discuss at the end.

A V-tail mixer has 2 inputs(elevator and rudder) and 2 outputs(left and right ruddervator). Here is how you would connect them:

Plug the A and C esc's into the outputs on one mixer(AC mixer).
Plug the B and D esc's into the outputs on another mixer(BD mixer).
Plug the elevator inputs from the AC and BD mixers into the 3rd mixer(main mixer).
Plug the elevator input on the main mixer into the Stick 1(U/D) output of the receiver.
Plug the rudder input on the main mixer into the Stick 1(L/R) output of the receiver.
Plug the rudder input on the AC mixer into the Stick 2(U/D) output of the receiver.
Plug the rudder input on the BD mixer into the Stick 2(L/R) output of the receiver.

Which stick is mapped to which receiver output varies between manufacturers, so you will have to read your radios specs or experiment to find the right receiver outputs.

Now for the caveats!!!
Like I said, this should work, but I have not tried it.

Next, to arm the ESC's, you generally need to set them to zero throttle input. This requires a mixer that will mix in 100% of the elevator input(ie throttle in this application). Most cheap mixers don't specify the mixing percentages. Postings on this board imply that the GWS will correctly arm the the ESC's, but I don't have any direct experience. There are mixers available with programmable percentages. They are more expensive, but would allow you to fine tune the mixing.


Jeff

PS What are you building?

[andrewm1973]

Darren,

I am going to sound like a broken down record always saying the same thing, however you could get a microcontroller to do this kind of thing for you with very little programming.

[sharpshooter223]

sounds like you are making a four blade helicopter?

[mmormota]

sounds like you are making a four blade helicopter?

If that's the case, the mixers have to be in the heli, because it needs gyros on all axis. It can be done using 3 gyros and 3 V-mixes.