By any means, I am not saying this will be easy! This is rough breakdown of what I'd attempt:

- Use the "brains" from the small ESC. If I was really good, I'd redesign all the circuitry for the receiver input, programming, and CPU control - but I'm not that good, so I'd cheat. :)

- Create a V/A amp (voltage and current amplifier) that will amplify the signal voltage to the battery voltage and amplify the current to 200A or more.

- Since the needed battery voltage (>50v) is quite a bit higher than the small ESC could handle, I'd initially bring the high battery voltage into the V/A amp and then also regulate it down to 8v to send to the battery input of the small ESC.

- Feed the three motor wire outputs of the small ESC to a voltage amplifier so the voltage is as high as the high voltage from the batteries.

- Then, use as many MOSFETs in parallel as needed to achive the current you want (>200A). Due to the way MOSFETs work, they can be easily paralleled. The devices would not be surface mounted, but typical TO-220 cases properly mounted to a heatsink. As you can imagine, the resulting

- Add some protection circuitry to the battery input and motor output of the small ESC so that if a problem occurs with the seperate V/A amp board, the ESC will still be usable.

- Use 6 gauge wire for the power, and 8 gauge for the final motor outputs.

I just wish I had a BL ESC to spare so I could experiment, something like the Mamba is pretty cheap at $80, but too expensive to just experiment with. Since it's not going to drive a low impedance load (V/A amp will take care of that), it won't even need a heatsink.

There are a few disadvantages to this:
- The V/A board will end up being rather large.
- The batteries that can supply this kind of current and voltage would be something like 4 or 5 car small batteries in series, which would be heavy!
- It would have to be a fairly large truck 1:6 or 1:4 scale to fit all the components and use driveline parts that won't shred with the torque!

my guess is the guy made it from scratch. How big was that boat!! :eek: i bet my fat arse could ride it! :005:

Well I suck at electronics, but this sounds interesting enough to get me to look into it some more. I was thinking of using an ESC like this (actually two) to power dual 3080s for making an electric go kart. My eyes have been opened. lol... now only if my wallet could back it up.


JB

What do you need to know about brushless motors to get the fastest one? will the wattage tell it all? or do you need to look at ALL the specs e.g kv, kt, wattage etc….

1/5TH SCALE diffs on a 1/8th to 1/7th size chassis basically all custom, make it big enough for 12s3p lipos..... 4 wheel tire smoke... cool but would you want to run a $6000+ rc that is destined to break itself all the time.

ummm..... yea, i do. Ok, well I dont have the money, but that would be really fun. Stick it in the 1/8 scale buggy class and OWN!!! lol... and why would it break all the time? It only would if you are a sucky driver or designed it poorly. Make it out of all steel. It could certainly push around that weight and probably wouldnt break either. Man that would be cool


JB

BrianG, so by the diagram you showed, the esc would be a brain and the amp would do all the HV work. Sounds like a slotcar controler i got, pretty good idea.

Darren why play with a motor that you can't get a esc for when a 1950 can be scary with 6-8 lipo's

Hmm... brushless pocked bike anyone?? :D

Man, that would be way, way, way too much fun :)

Too bad I don't have the time to do it.. hmmm that may work out for a hell of a final project for my engineering course.. :)

Don't the esc need a feed back from the motor to work. You would need to do something like a sensored for it to work out.

It might get a little pulse from the amp. if it goes in it should go back even a little

Yeah, I kinda forgot about that. :dft001: There may be a current-sampling coil or something on the motor wires that picks up the PWM AC signal. The switching frequency and current of the ESC outputs is high, so only a few turns around each lead would be needed. The only other way to pick up a current-sample I can think of is to use a VERY small value resistor and measure the voltage drop. But that would be less efficient, especially at the high currents these ESC can pass. Either way, I suppose re-locating the sampling coils to the outputs of the V/A amp, or calculating a new sampling resistor value to put at the outputs of the V/A amp would work. Then, feeding this data back to the "brain". Unfortunately, I don't have an ESC I can pull apart to see.

MOSFETs are voltage driven, so there would be VERY VERY little feedback from the V/A amp if you counted on them to provide feedback.

Oh yeah!
 

Well guys, my supermaxx is due to be finished before xmas. I've thought about doing the 3080 maxx for a while now, and decided that if I can find a 10S lipo 3080 compatible ESC, then the project will be started after I have finished my Supermaxx.

The truck will run all stock except for pinion/spurs (obviously) and I will 'try' to run a G2 chassis. The motor mount is my only real problem. Mike would you be up for making one? If so, i'll get a 'Sponsored by RC-Monster' shell for it, just for the thanks. The truck will ride as low as possible, using 4 UE SuperShocks. Not sure about tyres, maybe 40 series road rage's. Shell will be a proline crowd pleaser. I may run a wing if I see any hint of the truck lifting.

As far as lipo goes, done anyone know what I should use?

Now; I know that promod used dual 2240's and 8S lipo to reach 80mph. I'm 'hoping' that this truck will break into 3 figure speeds. Would this be reachable, I think so.

I know im going to get 'it wont turn' type comments, and i dont want it to. It's purely a straight line truck and will probably be sold not long after i've reached the hundred. Once the truck has been done, I'm gonna contact one of the rc mags and see if they can do an article on it. I will get video footage of the truck without a doubt.

This is gonna be like a jet fighter engine in a bicycle :)

i would really love to see this happen. you're just going to open the diff and it will look like you just cracked an egg open. lol it will be liquified

Last I heard Promod was only running a single motor. I don't know why you would need a dual 2240 setup. The limit is more in the cells than motor. I wish you luck though on project.

Thanks mate!

I believe you once had in your sig 'I have a dream of my maxx going 100mph'?

If that was you, ill send you the 100mph pic before anyone else :) .

What is the company that makes bearings, the orange shelided ones? boca? Might have to buy a bunch from them.