keithwakeham

Hello everyone. I have a project that I'm working on that is quite peculiar and would like some expert advice.

I'm doing an engineering masters related to torque vectoring in hybrid drive trains and me and my supervisor has been tossing around some scale model testing for validation. We want to take an RC car and setup a single motor in the front running a differential and dual motors in the back running each wheel individually. We may look at individual motors all around. We will then control the car through a micro controller which will us a torque vectoring program to allow the car to go around turns faster and prevent over and under steer. Validation by comparison to another identical car setup in FWD.

I'm looking for a car to do this with. The E10 from HPI looks like my best bet because I can remove the drive shaft and place a single motor in the front. I will have to design and machine the rear transmission parts I suspect though.

Does anyone have any suggestions on any other vehicles. I looked at belt drive but afraid of a lack of belt lengths and complex tension systems. Does anyone know of pre-existing multi-motor cars (on road or offroad).

Thanks and any questions feel free to ask.

shinta

iTrader: (1)

i say build the hole thing your self. dont use something all ready make. reason is you will spend more time trying to mod the car to get make thing fit when you can just build it your self and just fit thing in as you go. im working on something just like that. but its 4 motors not 3 it showing to be a main in the rear but. its coming along.

keithwakeham

I was originally avoiding building it from scratch because it would entail the significant construction of a lot of parts and was hoping for a more existing setup that would work with what we are doing. I haven't seen much though that seems suitable.

joe of loath

iTrader: (1)

The E10 is too unreliable, you'll all get frustrated with the way the platic flexes and mashes various gears. Look at a tamiya TT01, or team associated TC3/4. The associated ones are out of production now, but are easy to find second hand.

Would belt drive work? There are loads more belt drive cars, a tamiya TA05 would be the best if that's what you prefer.

sosidge

I think the E10 may be your best bet as a base - despite it's limitations as a hobby car, it should be sufficently reliable for some simulations.

The only other 1/10th scale on-road car I can think of is the Tamiya TA03F - this car is long since discontinued so would be a used buy only, and spares would be difficult to source for any customisation or repairs. It has the motor in front of the axle so there is more space for a custom rear end.

If you can fit your drive system into a slightly smaller package, Tamiya do an M-03 chassis which is a front motor "mini" 1/10th scale. HPI also do a front-motor mini called the Switch (I would go for the Tamiya every time).

Or, you can take a look at the current generation of shaft-drive 1/10th buggies. The Kyosho Lazer FS is a front motor car, there are also mid-motor cars in the shape of the Associated B44 and others. The larger size of the 1/10th buggy may make it easier to make space for your custom rear end.

joe of loath

iTrader: (1)

I just realised my mistake, ignore my suggestion of all the cars except the TA05. The TA05 has a center mounted motor, with enough space behind it for a couple more. The E10 wouldn't be reliable enough, with mine bits popped off all the time even when running with the kit motor (basically a cheap silvercan).

Or, how about the front end of an M03, and the rear end of an M04 bolted together? you'll have a front mounted motor, and a rear mounted motor, and you can butcher the rear about.

shinta

iTrader: (1)

i can under stand that. in that case i would try looking into just the chassis base and not a roller so you got a base to work off of. go to the local hobby shop and tell them what you going and tell then you need a big chassis to start off of.i would say a evader gear boxs would work for the front and then i would use the cyclone spur gear set up to run each back wheel. and just mod the shaft end to fit a dog bone in to. wouldnt be hard just take the shafts form a evader and cut the bars off and tig weld it to one end of the shaft.

man i wish i was there, or i could play in this shop for about two days i could build you the rear end set up.

Brian McGreevy

iTrader: (10)

It'd be hard to implement on a not-from-scratch car, but I have a good deal of familiarity with a traction vectoring/active differential system implemented on a Formula SAE race car. The end goal was exactly what you are trying to accomplish. If you are interested in what we did, send me a message.

keithwakeham

Thanks for the feedback.

I'm beginning to feel that a from scratch implementation might look to be a better way to go. It would allow removing many of the issues associated with modification but it still adds a level of complexity that we might not be willing to undertake just yet.

I've been toying with the idea of in wheel individual power units for an RC model. Has anyone seen this done before? I know in full scale it presents issues with unsprung weight for the suspension. Is heavy suspensions / wheels an issue for on road RC cars?

Rob Burns

iTrader: (4)

How about a pan car (RC10L, Corally 10X etc) run in reverse? The normally rear mounted motor would be your front motor and there would be more room on the chassis at the rear for fabricating a 2 motor rear drive system.

You would have to make it rear steer but I don't know how that would affect the results you're looking for.

keithwakeham

It's an interesting suggestion but because we are using an existing model to predict required torque and trying to replicate a real car under controlled circumstances would mean rear steering would not be usable. But thanks for the help.

wingracer

iTrader: (24)

That's not a bad idea.

keithwakeham

I'm still trying to find some decent pictures of the M03 and M04 without much luck. As far as I can tell the M03 was a FWD and the M04 was RWD. Are both of these available new?