Direct to diff outrunner conversion*update*

[zeropointbug]

These Scorpian motors look great, I would like to see the 40mm cans... in my hands.

I am just thinking about how much more space I would have on my Revo if the motor was gone from the engine mount, no tranny, and the outrunner motor was mounted down kinda under the tranny. wow. Get some bullet proof diffs and you are set! Nothing to wear out in the tranny... at least anytime soon.

[sikeston34m]

Originally Posted by zeropointbug

These Scorpian motors look great, I would like to see the 40mm cans... in my hands.

I am just thinking about how much more space I would have on my Revo if the motor was gone from the engine mount, no tranny, and the outrunner motor was mounted down kinda under the tranny. wow. Get some bullet proof diffs and you are set! Nothing to wear out in the tranny... at least anytime soon.

Yes ZPB, that's exactly what I'm thinking of. The motor will set about 60% "submerged" in the chassis. Just enough to make the drive shafts as straight as possible.

RCM has the 4.3:1 diff gears. This will drop the gear ratio to almost equal to an E maxx locked in second gear. If more gear reduction is needed, we can do that with the tire height.

The end result will be alot of lost weight. There will be alot of room opened up on the already tight E-Revo chassis. Alot of wear items eliminated means this thing is going to perform longer and hold up better.

[zeropointbug]

The only thing that I am wondering about is the 'spool up' of an outrunner in this configuration... will it have enough 'zap' to make for a pleasant throttle response, you know?

[MetalMan]

I think the acceleration will be dependent on how the ESC is programmed. If it's not fast enough, you could always decrease punch control on the MM, or do the equivalent on the Quark. If that's not enough, then a little adjustment to the exponential on your radio or to the throttle curve on the MM should fix any slow spool-up issues. I can tell you that the outrunner in my 2.2 rock crawler (the size of a 540 brushed motor) gets up to speed VERY fast, even when geared for 12mph and running a Mamba 25 on 3s Lipo.

This whole idea of outrunner-in-the-middle has intrigued me to try the same sort of setup in my MT2. The dual slipper clutch (torque control) idea is excellent, if it could be pulled off efficiently (not too heavy or takes up too much space). Thankfully outrunners are built such that custom shafts could be made, more specificially to fit into a custom slipper clutch setup.

Speaking of slipper clutch setup, we gotta get some sort of 3D model of one made using Revo components. The slipper clutch items would most likely need their own chassis-mounting hardware, so as not to put too much strain on the motor's bearings. I'll be thinking about it and maybe drawing one up.

[lincpimp]

From experience with my setup, the more aggressive starting power settings work much better. Using small throttle input cuased my setup to cog. If more throttle(around 1/10-1/8 total throttle) was given the motor started up with no problem and would easily spin the tires from a standstill. I am thinking a isolated mount for the motor may be a simpler choice than the slipper.

[lincpimp]

Dug this thread up from the graveyard...

Thought more about the potential slipper clutch idea I had. I gave up on it due to weight length and overall complexity.

But I am back with this direct to diff outrunner idea as we now have a good solid programmable 6s esc (MMM) better lipos with higher c ratings, and the cost of motors is slowly going down. So this is getting more viable.

But we still do not have any shock protection, or do we???

New idea, make the outrunner mount absorb some shock. Well not too new, I said it on page 1 3+ years ago...

But I have figured out a way to do it. Imagine the pressure plate on a manual transmission clutch. It has springs setup radially around the drive hub to absorb some shock by allowing the pressure plate to move slightly in the same direction as rotation. The springs are strong and stiff, but will give under heavy loads and provide some shock absorbsion. Or for you motorcycle guys, the cush drive on the rear wheels of a chain drive bike.

Same idea, just between the outrunner and the mounting bracet to the chassis. Imagine 2 disks, with springs setup in recesses that can act on each other. One disk mounts to the chassis bracket, and the other to the outrunner. The driveshaft from the outrunner would have to go thru the center, and both disks would have to be held together solidly to support the weight of the outrunner. But when shock was transmitted thru the tires,diffs, back to the motor this would allow the motor to "twist" a few degrees and absorb some of the shock.

So whatcha think bout dat?

[DrKnow65]

Linc, what about a torsion bar type driveshaft? Just like a standard dogbone, but
made to flex under load. Spring steel dogbones for all six shafts could limit gear busting shock.

[Semi Pro]

Originally Posted by lincpimp

Dug this thread up from the graveyard...

Thought more about the potential slipper clutch idea I had. I gave up on it due to weight length and overall complexity.

But I am back with this direct to diff outrunner idea as we now have a good solid programmable 6s esc (MMM) better lipos with higher c ratings, and the cost of motors is slowly going down. So this is getting more viable.

But we still do not have any shock protection, or do we???

New idea, make the outrunner mount absorb some shock. Well not too new, I said it on page 1 3+ years ago...

But I have figured out a way to do it. Imagine the pressure plate on a manual transmission clutch. It has springs setup radially around the drive hub to absorb some shock by allowing the pressure plate to move slightly in the same direction as rotation. The springs are strong and stiff, but will give under heavy loads and provide some shock absorbsion. Or for you motorcycle guys, the cush drive on the rear wheels of a chain drive bike.

Same idea, just between the outrunner and the mounting bracet to the chassis. Imagine 2 disks, with springs setup in recesses that can act on each other. One disk mounts to the chassis bracket, and the other to the outrunner. The driveshaft from the outrunner would have to go thru the center, and both disks would have to be held together solidly to support the weight of the outrunner. But when shock was transmitted thru the tires,diffs, back to the motor this would allow the motor to "twist" a few degrees and absorb some of the shock.

So whatcha think bout dat?

use a centrax clutch, or just mount the motor on rubber bushings, or make a 2 peice motor mount designed like an old servo saver to take off the shock loading

just some ideas for you linc

[lincpimp]

Originally Posted by Semi Pro

use a centrax clutch, or just mount the motor on rubber bushings, or make a 2 peice motor mount designed like an old servo saver to take off the shock loading

just some ideas for you linc

Just what I am thinking. I have the design mostly worked out. Pretty sure this will be in an emaxx, as I have a 3905 roller with lst diffs just hanging out.

Would a motor like this be viable for something like this?

http://hobbyking.com/hobbyking/store...idproduct=5140

Was thinking of trying out something like this on a buggy for fun. Installing a outrunner and running it wouldn't be that difficult.. would it?

[lincpimp]

That thing is massive. Not really what you want to do a buggy. I would go with a 53 series axi, similar to what sike used in his direct to diff revo. Or one of the scorpion motors.

Originally Posted by lincpimp

That thing is massive. Not really what you want to do a buggy. I would go with a 53 series axi, similar to what sike used in his direct to diff revo. Or one of the scorpion motors.

I was wondering if it was viable for anything really. Wasn't planning to use that in a buggy hehe. :P

Also, are the outrunners with the rotor sticking out both ends called something different?

[simplechamp]

I know this probably isn't that plausible, but just throwing ideas around, for an in-runner what if you could somehow mount the rotor to the shaft with a shock absorbing design similar to a rubberband/o-ring prop-saver on electric planes? It would have to be much tougher than a rubberband or o-ring, but you get the idea.

[lincpimp]

Originally Posted by simplechamp

I know this probably isn't that plausible, but just throwing ideas around, for an in-runner what if you could somehow mount the rotor to the shaft with a shock absorbing design similar to a rubberband/o-ring prop-saver on electric planes? It would have to be much tougher than a rubberband or o-ring, but you get the idea.

I hadplanned to do someething like this to the area where the motor mounts to the motor bracket. Thus the driveline shock would be isolated right at the motor.

[C-5Quad]

if you have access to cnc just down size this and add a collar to contain the rubber under high torq...or something similar. I use to maintain 90hp brushless water pumps and they used a similar vibration damper.

INCH
Couplings
Flexible Geargrip

http://www.vibrationmounts.com/Store...=Products9.htm