Running 2 speed controls in one car?

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THEYTOOKMYTHUMB
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Running 2 speed controls in one car?

Post by THEYTOOKMYTHUMB »

Let me start by saying that I have no intention of doing this, but just asking. It's about a 25 minute drive each way for work so my mind just kinda wanders(well it does while at work too). I was just wondering if "in theory" you could run two escs off one receiver by splicing the wires together. Would the voltage drop from the receiver to the esc be too great for them to properly receive instruction? If so, what about using a receiver battery with a higher voltage? I know they have servos that can handle higher voltage so there should be no issue there. How high of voltage the receiver handles would certainly be called into question. I might be missing a very obvious flaw here. Again, I am not trying it, just curious if it is possible.
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Re: Running 2 speed controls in one car?

Post by soniccj5 »

That would make a good setup for a ClodBuster so you could run two batteries.

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Re: Running 2 speed controls in one car?

Post by purpletimbo »

I have seen it done, but simpler to go twin motor esc route from emaxx etc

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Re: Running 2 speed controls in one car?

Post by a01butal »

I recently sold a Clod on eBay with dual Rooster speed controls. I didn't build the Clod as it was acquired in a large lot of cars and parts that was purchased out of a storage unit that had defaulted on its rent. The reason it was done is still a mystery but the mods to the Clod allowed the use of 7 "D" cells to extend the run time. It was a nice looking mod but I had many questions as to why it was done.
http://cgi.ebay.com/Tamiya-Clodbuster-w-Motors-Servo-and-Dual-Novak-ESCs_W0QQitemZ230383937089QQcmdZViewItemQQptZRadio_Control_Vehicles?hash=item35a3f3e641
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This is all very interesting!

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Re: Running 2 speed controls in one car?

Post by THEYTOOKMYTHUMB »

a01butal wrote:I recently sold a Clod on eBay with dual Rooster speed controls. I didn't build the Clod as it was acquired in a large lot of cars and parts that was purchased out of a storage unit that had defaulted on its rent. The reason it was done is still a mystery but the mods to the Clod allowed the use of 7 "D" cells to extend the run time. It was a nice looking mod but I had many questions as to why it was done.
http://cgi.ebay.com/Tamiya-Clodbuster-w-Motors-Servo-and-Dual-Novak-ESCs_W0QQitemZ230383937089QQcmdZViewItemQQptZRadio_Control_Vehicles?hash=item35a3f3e641
That's pretty cool. Do you remember how the receiver plugs were wired? I could only think that they did it to get more amps to each motor?? It originally came up as an idea to put 2 Mamba Max 5700s in a Savage I just got. It was a thought that came and went very quickly. It would destroy the tranny. :lol:
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Re: Running 2 speed controls in one car?

Post by jwscab »

there is no reason you can't run two speed controls. Plane guys do it all the time with running twin(or multiple) brushless motor on scale models.

There is one thing you have to do, and that is, be sure that only one ESC powers the receiver. The esc has built in BEC, so it powers itself, and then back feeds the receiver and servo, through the red wire. The problem is, each esc has it's own bec, and if joined in parallel, will slowly(or sometimes quickly) burn each other out by providing slightly different voltages, which generates currents, which has no place to dissipate except inside the bec circuitry as heat.

so use one esc as the 'master' esc, and keep the red wire in the receiver harness. all the other escs, clip the red wire, so that it will only power itself. Run all the battery positives together, and all the negatives together so the inputs are all paralleled. Then run the individual oututs to each motor(brushed, or brushless).

I think you can probably use about 4 esc's before the signal termination becomes too low and kills the signal. Not sure on that, but I know two will work, lots of guys do that with steering servos(trucks), and flaps/ailerons(planes)

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Re: Running 2 speed controls in one car?

Post by THEYTOOKMYTHUMB »

Thanks for the info jw. 8) It will be good info to have if I get bored one weekend and decide to do something crazy.
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Re: Running 2 speed controls in one car?

Post by vwjuice »

Couldn't you just use a "Y" harness? That's what you do for dual steering servos.

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Re: Running 2 speed controls in one car?

Post by jwscab »

yes, if you clip one of the red wires so that both esc's don't try to power the receiver and steering servo.

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Re: Running 2 speed controls in one car?

Post by SteveK »

As has been mentioned, some guys used to do this in Clod Busters, but once ESCs got better at handling multiple motors and higher voltage, and battery capacities grew, you really didn't need to do this. You get as much voltage per motor if you are running a single battery and ESC and have the motors wired in parallel, so you will just get double the run time with a second battery. However, then you have to deal with the weight of a second battery and ESC, the cost, the complexity, etc.

That's is a good point about the BEC: I've seen this done in magazines several times, but I don't think they ever mentioned cutting one of the power wires.

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Re: Running 2 speed controls in one car?

Post by mark »

I ran two traxxas brushless esc's in my Clod, I just used a Y harness, the truck was crazy fast.

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