A few questions

[jamietoeg]

I plan to build my own featherweight lifter robot soon but after a fair amount of research i had a few questions that i couldn't find the answer to. I hope somebody here can help me out.

1. I plan to use these speed controllers http://www.ebay.co.uk/itm/High-Volta...MAAOxyhS9Tfqfw instead of the botbits ones because they are cheaper but i don't know if they would work or what anyone else thinks of them or if anyones tried to use them in the past.

2. When you wire up your motor controllers i assume you put one esc to channel 3 and one to channel 4. However i don't understand how or why you could mix the channels to make both go forward when you push the stick forward and both go backward when you push the stick back using some kind of channel mixing. Is there a tutorial anywhere for this for a dx6i.

3. if you take motors out of drills is it also possible to use the drill batteries on your robot. i think i read somewhere that the best battery choice for featherweights in NiCd which are the kind you use in drills. if not, where and what do you recommend buying.

4. Can you use a control board like the cc3d of NAZE 32 to control your robot as well. i wonder why people haven't done this in the past as it looks like a much simpler solution.


Best Regards
Jamie

[R9000]

Hey Jamie,

1. Never used those I'm afraid, I think most people tend to stay away from the off-brand controllers rated for disproportionately high currents on ebay. You could give them a try though, if you're willing to take a gamble, but beware they might fry under high loads. ^^

2. The reason you want to mix channels is to allow you to go forward, reverse, and turn, all on one stick. You can set this up on your DX6i with the mixing option (if you go into the menu). I can't remember how I did mine right now, but I plan to make a video guide when I figure it out again, for us roboteers specifically. Although I'm not sure if my way is the optimal or best way by any stretch.

3. Cheap cordless drill batteries are usually poop, and most people these days are using LiPos to power their machines. I think the drill batteries have fairly low power efficiency and current output, so I wouldn't bother. Though it is handy just keeping them around for when your drill runs out of charge, you can just pop another in and put your old one in the charger. Not much else I know of that you can do with them though. :/

4. Short answer? Yes, probably. But if you mean using it as an ESC as well as a receiver, I wouldn't think it would hold up with the currents that drill motors tend to draw. But I'm no expert on those things, so I'll defer to someone else on that.

Hope that helped, but I'd say most others on this forum know more than me (I still haven't finished my bot, but it's very close), so check out their advice too.

[Pinski1]

Hey,

1. Those speed controllers are garbage. I'd recommend TZ85As. They're bloody bulletproof.
2 & 3. As R9000/Rory said.
4. A Naze/CC3D is completely useless for combat robotics, why would you want a multicopter flight controller in a ground based vehicle?

[daveimi]

1. Sorry the guy above hasn't really read you're post properly. There are a few of us on here that have used cheaper controllers with success, it's mostly just a case of being careful what you buy. The amps quoted for the linked controllers will be for peak amperage, not continuous. They're also very expensive for what they are, if your after some cheap controllers to have a go with I can link stuff that's a lot cheaper to run a pair of drills.

2. You could write pages on mixing. It's basically if you had each motor on a separate stick, you'd push both forward for forward, back for back, and one forward one back to spin the robot one way or t'other. By using mixing, you can put fwd/bk and turing onto one stick so when you push left, the transmitter realises you want left and spins the motors opposite directions. Mix fuctions are available on transmitters or dual speed controllers, so be careful what you buy. Ask if you need more info.

3. Yes you can use drill batteries, but they take forever to charge and weight a ton. Learn about Lipo's (again can explain if needed) and get one of those. They're only a tenner.

4. cc3d and naze32 are flight controllers for quad copters with gyros n stuff built in. They work in 3D and their functionality doesn't really give you the option to reverse motors for tank style steering. They're designed to keep a 250 race quad level. Getting the controller for a robot is just a lot simpler.

Anything else just yell.