Couple of questions

**ady** · 1st July 2012, 19:23

I have converted k9 to 4wd, will a sabertooth dual 10a run 4 drills on 2 12v sla 7 amp, I have run 2 fine.

Also I am adding a second speed controller for k9's head movement, it's a 12v that I have lying around, will I need to cut a wire for the bec, as the sabertooth power the reciever, if so what colour wire is the bec?

Thanks for any help

**Anttazz** · 1st July 2012, 19:32

To the first point, I think 10A is maybe a bit of a push for 2 drills, although I suppose it depends, what sort of weight is K9? I don't think i'd fancy risking blowing the ESC up.

Second question, what type of controller is it? There may be a way to deactivate the BEC on the controller which would make it easier to reactivate if you wanted to use it elsewhere. I've never had any issue with having 2 BECs connected up but if you really need it off I think you only need the signal wire going into the receiver (so red and black can be cut) but i'd double check that.

Hope that helps.

**Ellis** · 1st July 2012, 19:38

I can't help on the BEC front but I'd be wary of running 2 drills on 10 amps. A drill may pull upwards of 10a at stall. For combat I'd be wary of even a single drill with a 10a ESC. Then again, this is likely to be far more relaxed than combat.

People run the 25a Sabertooth model for 2 drills quite often.

**ady** · 1st July 2012, 19:40

Thanks for reply, I have run 2 no probs, k9 has 100mm blue wheels, now I'm trying my luck with 4 motors lol, I know I'm pushing my luck lol, but he isn't put under any strain or stalls

Since reading up on my controller it is no good as it can't run on 12v, could I use a battle switch? Basically I want To make a 12v wiper motor turn on and off for his head movement, I want to press stick on transmitter forward so his head moves then when I release stick it stops

**Anttazz** · 1st July 2012, 19:50

Depends on what weight he is too. Anything close to a FW and I don't think i'd waste the Â£35-50 of magic smoke thats going to come out. On top of that, you probably don't want to be doing maintenance on a non combat machine after every event you attend, which you will have to do if you cook a Sabertooth. So if I were you, i'd over spec it. Presumably it'll run for more than 3mins at a time too, unlike our FWs so the heat can build up more than it would in our FWs that run Sabertooth's.

You could do that with the head, but you couldn't reverse it, you could use a servo and 2 switches though and that would do the job for cheaper than a battleswitch would and you could move the head in both directions. I saw a link to that method recently somewhere, although I didn't click on it. I could take a photo of the drive system from Rover if the link can't be found though as it uses the exact same thing.

**ady** · 1st July 2012, 20:03

Yeah I was thinking I will have to go with a 25a sabertooth lol, will go with battle switch as I don't need to reverse motor, as it's on a cam, so one direction is ok, those dual 10a I used to use 2 in my fw cluster bot, running 2 12v drills and they worked fine but I think it's pushing it a bit with 4wd,

I got a fan I could mount on speed controller so tempted to try lol, would it be heat that killed it?

**Max** · 1st July 2012, 21:23

You could add 10 amp fuses and test it, if they blow then it's only 50p worth of fuses gone rather than the whole sabertooth

**Anttazz** · 1st July 2012, 22:23

Ahh ok, battleswitch should be ok then as I presume the head isn't too heavy so won't draw more than the battleswitch is rated for (10A I think).

Its current that would kill it, but the current is what generates the heat so kind of yeah and a fan probably couldn't cool it enough, but i'm just presuming there. For the type of robot it is I personally would put an controller in there that would stay cool if I ran it for 12hrs at a time without the need for any additional heat sinks or fans as it would cut down a whole host of problems that you'll encounter.

Assuming that you'd be buying a battleswitch you could always spend a bit more and buy something like a Scorpion XXL or BotBitz 25 or 85A (or a host of others) and use the Sabertooth on the head and new controller on the 4WD system?