dual motor drive

[knightstar]

You can increase the available power by useing two 1kw motors either in tandum (two motor drive) along side each other on single sprocket driven chain or mounted in opposition with drive sprocket in the middle. With opposition arrangement, motors would have to be hooked up to controller with one motor in reversed polarity in relation to the other. A fabricated common shaft coupling with center welded sprocket would give twice to power. Controller would have to be rated +1kw at whatever voltage rating desired

 

[vanilla ice]

Oh.

 

[grindz145]

You still need twice the current out of the controller anyway...

 

[recumpence]

Not sure what the point of this thread is. There is no specific project stated, or any questions asked.

This is also a pretty obvious statement. Many of us are already running twin motors. :?

Matt

 

[grindz145]

I think his only point is that you can run one controller into two motors but... yeah...

 

[rkosiorek]

only if the both motors are brushed. brushed motors perform the commutation internally.

brushless motor controllers perform the commutation function for the motor, so unless both motors are locked together so that both have exacly the same electrical postion at the same time it would be impossible to run two brushless motors together. locked together that way the pair of motors would electrically become one.

rick

 

[spinningmagnets]

Not that I'll ever do this, but a question occurred to me. Since the brushed perform the commutation internally, is it possible to run a brushless and a brushed motor from the same controller (no synch issues?).

I am actually a fan of using two motors (on a E-motorcycle) so if yes, its a useful option...

 

[vanilla ice]

You mean a single brushless controller controlling both a brushed and brushless motor?


I had ideas in my head of using like four of those 7000w RC motors for a fast motorcycle.. I like the modularity of it, and it would allow the use of inexpensive off the shelf controllers. Unfortunately from what I've read on ES four 7kW's does not equal the performance of a single 24kW motor. I may still end up trying a more modest dual motor setup like Frankg's trail bike except with kolls.

 

[diver]

on my trike, i have a mars etec brush motor on each rear wheel powered by a single altrax 450 amp 72 volt controller. man i love this thing. way to much fun

 

[etard]

This thread reminds me of those awkward Ben Stiller moments where you bust in on a conversation thinking you know alot about something, but then it turns out they were talking about something completely different or on a much higher level. Don't worry Knightstar, stick around here a bit, there will be plenty more examples of people knowing way more about this stuff than you ( at least that's how I feel sometimes). But maybe next time do a search for "dual motor drive" and see what you come up with. Also there are rc motors capable of producing over 5 kw, 1kw was so last year. :wink:

welcome to ES, usually we are a much friendlier bunch, nobody likes a know-it-all though.

 

[recumpence]

I have no problem with his statement. It is very true. However, it is kind of out of no-where, if you know what I mean. It is just strange to make an out of left field statement with no background of what is being dealt with. It is almost like he is answering a question that wasn't asked.

Anyway, always glad to have a new member.

Matt

 

[rkosiorek]

personally some of my own personal most embarassing moments have occured when half way through a very ingeneous argument, where i have completetly humiliated and insulted my opponent i suddenly realize... that i am completetly, utterly and obviously wrong.

now that really sucks.

rick

 

[grindz145]

It's funny because I'm pretty sure everyone has their own idea of what this thread is talking about...:-D

 

[vanilla ice]

Lemonade out of a lemon..

 

[nsasch]

This topic excited me when I first saw it. I've been meaning to start a thread on dual motor drives, but I had no question and no profound statement or new data. I still don't know what this thread is about, but.... dual motor drives!

So, for a time far in the future where time and money is no object for me, I'd like to build an e-trike, custom built, and register it as a motorcycle. I'd want about 30kW with the relative simplicity and efficiency of RC motors. They'd have to be sensored, as there would be no pedals to get it started, and it would need at least 3 gears (really slow, low, high).

Anyway, I think dual, quad, or more setups would be best.

Unfortunately from what I've read on ES four 7kW's does not equal the performance of a single 24kW motor.

Is that true? I'd like to get a bunch of motors outputting to the same shaft, which would drive a rear (motorcycle) wheel. I've figured with some simple computer control, multiple motors can be run for ideal efficiency. If you want 6kW, 2 7kW motors shouldn't run at 3kW. That's inefficient. The computer system would run only one motor (cycling through them for longevity).

So, redirecting this thread a little to my interests... what do y'all think about using multiple motors for a very high-power setup?

 

[vanilla ice]

It'd be fantabulous to be able to use multiple cheap motors/controllers to get up to power levels where the big singles cost an arm and leg. Unfortunately the limited testing that a few ESer's have done with dual motors shows that the power doesn't necessarily add up as simply as one would hope. Multis work good for dividing the load and heat between two motors, but more data points are needed imo before we have good estimates of how the power numbers will churn out for multi setups.

 

[spinningmagnets]

"...what do y'all think about using multiple motors for a very high-power setup?..."

You mean, like this? (Otmar Ebenhoech Porsche 914)

 

[spinningmagnets]

Here's a recent thread on dual motors, and one pic out of several:

http://endless-sphere.com/forums/viewtopic.php?f=10&t=12364#p195700

 

[etard]

I really can't think of an example where it would be better to have multiple cheap motors and controllers rather than one nice motor and decent controller at the power level you guys are talking about. But then again here I find myself on that damn hobbycity website looking at those cheapo HXT motors and wondering if I can justify spending $800 on an Astro. :|

Actually a dual motor setup might be advantageous in an airplane, sort of like a twin engine plane that can fly on one engine in the instance where only one engines fails. On the ebike you can still get home on one motor, albeit that motor will be puffing the whole way. But then again that kinda negates the whole advantage of a hybrid system such as the ebike. :wink:

 

[rkosiorek]

i can see some advantage to DC-Brushed motors being used in pairs. they can be used in series for low end grunt and switched to parallel for high speed. several large size motorcycle and car designs do this. and they are using really nice motors and controllers to get ultimate performance.

but in the case of the brushed systems only a single controller is used. it is not really a solution for brushless where this type of switching is not possible.

rick