Say I wanted to drive two fairly high power motors maybe 12v 5a. I want them to drive tank style, one left one right. No need for reverse, just various forward speeds to weave a path. What do I need? I’m guessing some speed controllers and a receiver. Ideally I’d like it work from a single joystick forward and left/right to divert power rather that one joystick per motor. Any pointers? Any good shops for the bits?

I thought about this a few years ago for an R/C rock crawler application and started tinkering around with a small servo that switched on or off two microswitches that were able to handle that kind of current current. It wouldn’t so much as divert power but more switch it on or off though, but simple and reliable.

I’m sure there’s other solutions!

I think you’ll need some kind of programmable transmitter to handle the tank style steering.

Try googling..

“2 brushless motors mixed to one channel” or

“v tail mixing radio control”

this might let you do the one stick for forward and left or right. Modern radios can be programmed to do all sorts, but may be a bit tricky if you are not familiar..

Sort of like this…

http://www.rcuniverse.com/forum/brushed-brushless-motors-speed-controls-gear-drives-123/7569639-2-escs-2-lipos-2-different-channels-1-reciever.html

http://www.hobbyking.com do all of this sort of stuff..

Brushless motors, brushless speed controllers, lipo batteries

These do various sets that could be programmed to do what you want. Not that you have said really what the application is..

https://www.spektrumrc.com/

Enjoy
Chris

Yep – I think I could do this with my DX6i and the mixes, though it’s not immediately obvious to me how. That’s a very basic programmable TX though, there are others with far more flexibility.

However I suspect the OP probably doesn’t want to pay £100 for a TX, in which case there is another way – use a mixer between the receiver and the speed controllers to do the mixing. My first thought was this would be an interesting project with a microcontroller which wouldn’t take too long (I’ve got other projects doing similar things) and I might offer to have a go, but then I realised somebody must have already done it:
http://www.mtroniks.net/prod/RC-Accessories/Tankmixer.htm

Various pre built mixers..

http://www.action-electronics.co.uk/mixers.php

Actually, good call on Hobbyking – it mentions V-tail mixers on the page I linked, and TBH one of those should pretty much do what you want:
http://www.hobbyking.com/hobbyking/store/__31887__TURNIGY_V_Tail_Mixer_Ultra_small_UK_Warehouse_.html

Do you need much range? If not I suspect there is an even cheaper way. Two brushless motors, two speed controls and a low range transmitter modified to do the mixing. You can get the cheap spektrum transmitters that come with basic models off eBay very cheaply and I think they do mixing. Simple demo at the end of this video:

http://flitetest.com/articles/diy-pocket-transmitter

Good luck!

Nope – unless they’ve significantly changed the functionality which I doubt. I’ve got one of those and no mixing – I’m not sure where you think the mixing controls would be (my DX6i has an LCD display and extra buttons for all that).

That mtroniks thing inquire cool, no idea they existed. Used to be sponsored by them when I was a kid, good to see they are still going.

You can get 2-channel speed controllers with on board mixing, such as this one. Available here.

Possibly a touch elaborate for your purposes, and brushed motors only.

Thanks all some reading up to do. A few good search terms. That tanks mixer looks good as does the scorpion XL (although out of stock there). I don’t mind spending a few quid if it makes life easier, although also happy to do some Adruino interfacing if needed but it seems that it won’t be. Brushed motors is probably going to be fine. I haven’t specced them yet but they are likely to be pretty basic.