Is it possible to fabricate a differential for esk8, thus allowing for less motors but still getting 4WD?

I would like to throw out there is a cool spur gear differential that does not use expensive bevel gears.

220px-Spur_gear_differential_(Manual_of_Driving_and_Maintenance)
vs
220px-Differential_(Manual_of_Driving_and_Maintenance)

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I agree, but typically my Ducati is less reliable than either of my Honda or Kawasaki motorcycles. Likewise my RAM 1500 is more reliable than my Focus ST.

Performance Vs Practical not generally a 1:1 for Sport vs Commuter so I get you. The topic of the thread is “is it possible” not “why shouldn’t you” so you are 100% on point.

The point of argument that I jumped in on was not the main topic of the thread but simply “Why bother” as asked by @b264 which is a valid question in the grand scheme of things.

I agree with the sentiment here but I’m not sure if I would consider a Diff as a performance part in this scenario.

Getting a (pair of) motor(s) big enough to replace two (four) other motors is one problem, then you have additional problems such as braking and even the motor controller for a motor big enough to replace two 6374’s would need to be beefy enough to push the current. On top of that, if you wanted traction control not having independent controllers on each wheel (motor) would effectively remove this as an option.

So to the point of the thread can it be done - I’m sure it can be done, and I’d be happy to try and tackle this over the next winter if someone else doesn’t before I get my MPCNC setup. I just don’t see the performance benefits, or cost benefits. Then again all of my interest in eSk8 is in the eMTB area which may be coloring my opinion.

My idea is that a diff truck would allow a motor to be mounted via driveshaft to the board instead of the hanger. This lessens weight and would allow the board to feel more nimble.

I’m thinking very out of the box on this at least, to me, it’s not like, hey lets move the motor slightly on the truck and add a bunch of parts.

What I imagined when I see differential is: A central motor housed in the center of the board, inrunner type in the 80-120mm size capable of 20+kW, at 100k+ RPMs, using a go-cart ESC, sending power to a single dual speed transmission to distributing power to both axles via articulated twin drive shaft to each axle, using limited slip differentials. So yeah, very performance oriented.

Twin driveshaft would be counter rotating to stop any kind of torque steering at the truck, maybe even an electronic posi-lock for full diff locking for AWD

I think, if this can be done at the RC car level, no reason why it cannot be scaled up to eboard level.

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I ride single drives all the time, even in the rain and sometimes snow. Obviously they have less traction than dual, but they are relatively straightforward to operate.

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That’s 99% marketing bullet point and 1% real life problem. I ride singles all the time.

a diff is just an over complication for a skateboard where the wheels are ~ 8 inches apart.

my current build is an all wheel drive (4 hub motors) with the left and right side on separate throttles and the only time steering is difficult is if I have full throttle on the left and am trying to turn right… and the wheels are 25" apart on that.

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4 wheel ultra compact gear drive 5045 is what I wanna see. Weight of two 6374s

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Ok now you’re pushin. On even 2wd and 4wd when the wheels lose traction, it yanks the board to one side. Acceleration needs to be biased to rear wheels by about 50% during launch or the front wheel does a burnout and you’re never sure which front wheel grabs first and yanks the board in the other direction. When you’re braking and you’re skidding the back wheels, there is noticeable side to side shudder, which is why on 4wd I bias 75% of braking force to front motors. Heck, even the raptor motors would spin a wheel on a sharp turn.

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This thing is so awesome, Benjo!
Great to see someone did it this way.
Jenso did something like this with an inrunner motor but i bet you know about that :wink:

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so much this this this!

Is there no chance to run 1 motor on 2 esc to have a safty backup?

Not sure but at that point you might as well just spend another $100 and have a second motor haha

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That would truly be kinda stupid :eggplant:

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its not always about the money, its about what is possible.

thought it could be somehow like a second belt for one motor like it is done with the extra long shafts on single motor 2WD, you know what i mean?
If theres trouble with one esc, theres the other one as a backup.
Just for sience, doesnt have to be the best idea in the world. :man_shrugging:

No I’m saying the only point in ever running 1 motor and a differential/same shaft is to not have to use a second ESC lmao.

At that point, I think everybody can agree, use a second motor.

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yes i know dude, but i just simply fucking cucumber in ass asked if it is possible mr knowing it all!

Just in case you’re unaware,

Sorry, I guess I misunderstood why you’d asked.

I believe you can run 2 esc to same motor but it’s slightly complicated programming wise

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Yeah, thanx dude. Now i am happy.
peace bro

Dude, I ride 15" wheelbase singles all the time and yeah occasionally this might happen but it’s 99% marketing point and 1% real life problem, and I’m on the setup where it’d be the biggest problem of all.

I’m not saying that’s not a thing.

I’m saying it doesn’t matter. Saving the cost and complexity and risk of failure from all the extra parts is a much bigger gain for me than fixing this which is almost irrelevant and almost never is a problem.