Dual MM + One Motor= ?
 

I was thinking of doing this seeing that I already have two MM's on hand and would like to keep them instead of selling them and getting a MMM. I would like to run dual MM's in parallel into one high amp draw motor while running seperate lipos for each MM ESC. Is this even possible Im guessing it is if both lpo are exactly the same voltage and amp rating output. But what Im worried about is the ESC's fighting each other...

I threw this out ther a while back, as long as the escs are set the same they will be fine, because they are both being timed off the single emf pulse.

To be safe, you should parallel the LiPos prior to the MMs, and make sure all of the wires from MM --> Motor are the same length.

An interesting idea, but do you really need 200 amps at 4s?

Going to have quite a bit of battery weight. What are going to put this in? What motor?

Probably his Humungous outrunner, hes probably gonna run 8s with the beast

Doubling up mms will not double the voltage capability, just the amp capability. So it would be a 200amp 4s esc, maybe 5s.

Yes that is what Im looking for linc. I dont want to buy a MMM at the momment but want to pair up two MM's in parrallel to see how well it does. And yes if all goes to plan I will either be running dual 4's or dual 3's. Seperate pack for each MM.

Well if u sell both mms, u will have enuff to get the Triple M

Just take into account that the higher the current, the more inefficiency you'll have. Everywhere you have resistance in the circuit, you lose power in the form of P = I^2 * R.

in short u mean resistance(whic leads to) heat
He told me he was gonna run a micro ducted fan to cool his setup off... Wouldnt the doubled current potential far outweigh the extra wattage used as heat?

I will be running a 53/30 stator outrunner and dont feel safe running 8s on a MM "Wonder Why":lol: so thats were this idea came from. Heres a sketch of what I would like to complete...

http://i301.photobucket.com/albums/n...U/MMdual-1.jpg

It will probably be ok in terms of the heat dissipation, but it's really a poor idea compared with going with a higher voltage and less current.

Look at it this way as an example...you have a 2000W load...

2000W on 4S = 135A, so 67.5A per MM designed for about 100A continuous (IIRC)

2000W on 6S = 90A on a single MMM designed for about 200A continuous (IIRC)

I know which one makes more sense to me. IMO, sell the MM's and buy a MMM.

That's not 8S, it's either 4S2P or 3S2P.

Well, that has the mm paralleled, which will double the amp capability. Your motor will only see 4s though, not 8s.

Oops I wired it wrong... Ill try and fix it quick.

I dont know if this would work...

http://i301.photobucket.com/albums/n...U/MMdual-4.jpg

That would fry the mm fets... each esc would see 8s.

We all do respect, but that is very stupid idea... not good. First, FET's can't be series connected like that, and second the PWM of each controller would be fighting off on another... I think this would cause all sorts of problems, like maybe smoke show?

So... I don't get what you're trying to do here? It still looks like, when all is said and done/wired, both MMs will be seeing 8s, which means they're going to go poof.

For battery wiring, you could either just put one pack on each controller. Might be better to parallel the packs together and then y out 2 plugs for the escs. So basically put all of the positives together and then all of the negatives together.

Still think that one esc would be better. I am not sure how well the two escs will work together. Plus if you fry one during the run, the other will most likely let go due to he entire load being placed on it. Just sounds like a bad idea.

Sorry, that stupid idea will end up with fried ESC 100% and maybe motor too.

First of all it its not analog signal that goes to Motor but short impulses you cant just merge them you need somehow syncronizate them. Idealy it may work if all compnents and everything 100% indentical. Even same fets from same batch are bit different so no chance! To make 2 ESC work you need one Fet driver in other word brainboard to make work fets in sync. GriffinRu allready made it, he doubled MM powerboards and drived thems with one brainboard.

Forget it!

And if you still think that it work out dont forget to take camera and film how holy smoke escape form ESC's :diablo:

Yeah, if you're set on this, I'd pony up the cash and have griffinru turn your two MM esc's into a stage 2.

I meant to write 6s in the battery for my last diagram so that both esc's see 6s not 8s.

6s on a MM. Unless you have enough money for some "expensive" fireworks, I would not recommend this. Nevertheless, we need to get GriffinRU in here to give us a "How-To" on wiring, and MM over-voltage. :rules:

The max u can go on the MM is 5s td, im pushing it with my 5s now... Remember your fight with overvoltage protection the other day(5s)? with 6s the esc will go "EFF YOU!!!!"

It may even make a racist joke against you. :love:

So a mexican, a jew and a cracker walk into a bar...

Hey i resent that, im black...

Midgets
 

Sorry, so a mexican, a jew, and a cracker walk into a bar that is predoninatly black...

It is hard to make a racist joke that covers all of the races evenly. I try to be a PC as possible when coming up with a racist joke, but sometimes it is not easy.

My apologies to anyone that I have not offened properly, I will try better next time.

lol, I never thought I'd hear someone being offended for NOT being included in a racial joke. :lol:

BTW: Don't do two ESCs on one motor. Just asking for trouble IMO. The only way to reliably do it is the use the brains signal from one master ESC, either via direct paralleling of the FET PCBs, or by some non-existent linking cable.

Link to the non-existant cable: link cable to parallel 2 mamba max esc power boards

:rofl:

Nice Lincpimp! :lol:

lol, I should have known not to click that link considering the source. :no:

I'm sure he could have come up with much worse. He probably had to restrain himself to post that even.

You could split the power across the motor like so: http://www.powercroco.de/schemamodus12N_DD.html
http://www.powercroco.de/schemamodus12NLRK_DD.html

Each three coils would have one ESC, AKA half of the motor per ESC.

lol, nice JRH, but I highly doubt he's gonna re-wind his motor. Sounds neat though.

Sorta true, but for some reason I just wanted a pic of a banana. When I searched banana on google I found the crazy nana pic and had to post it here.

I try to keep things clean here, I know the rules!

So no go on the idea? Just thought I'd throw it out their. Guess Im going to have to get a MMM after all...

You can try it if you don't mind taking the chance in blowing two MM ESCs. Better yet, why not sell each for like $75-80 and get the MMM outright without spending a dime out of pocket?