clock tranny, center driveshafts, reduce torque twist

[mulepic]

Hi All,
I searched around but didn't find any info on rotating the tranny to center the driveshafts. Yes it would raise the motor but has anyone tried it? Maybe the benefits out weigh the downside. Any info and/or pictures are much appreciated.

[mulepic]

How about those that are running narrowed skip plates. That would make the driveshafts more centered, do you feel this helps reduce the torque twist? What's the width of your skid plate?

[chops1sc]

I don't see where it would change anything. The torque is still being applied no matter where the shafts are. If you look at the "mirror" mod for the tranny, the position of the shafts are changed but the twist is still there. I may be totally wrong, but that's what I think.

[overkillphil]

I would say that since most things that apply to the 1:1 world apply to our crawlers, low center of gravity rules. Take a look at 1:1 comp "moon buggies". Their driveline setup is almost identical to the AX10. Axle torque can be fixed by arm length and angle setup.

[Boogie]

Originally Posted by chops1sc

I don't see where it would change anything. The torque is still being applied no matter where the shafts are. If you look at the "mirror" mod for the tranny, the position of the shafts are changed but the twist is still there. I may be totally wrong, but that's what I think.

The twist is still there, but with the mirror mod, the weight of the motor is working against the twist rather than promoting it. With a 4link rear and a mirrored tranny, that pretty much takes care of the twist as much as you're going to get on a shafty. There are of course minor tweaks and mods with your shock setup as well, but the 4 link and mirror mod are the two big players in REDUCING torque twist. Unfortunately, with a shafty, torque twist of at least some amount will always be there...but you can at least make it manageable.

[chops1sc]

Originally Posted by tcabner

With a 4link rear and a mirrored tranny, that pretty much takes care of the twist as much as you're going to get on a shafty.

You are right about that. I have done both as well as double triangulation of the lower links and raising the rear upper links on the chassis side. I eliminated most of my twist. The only time mine wants to twist up is if I am trying to hit a very steep slope or starting to climb a tall rock. Once I get it going I just let off the throttle to let the right front settle back down then off I go! On the inclines I just keep it going and steer back and forth to bring the tire back down. I have a video I am editing now that shows a perfect comparison between mine and my friend's AX-10. I will post it once I am done.

[mulepic]

So is the true reason for the torque twist b/c the driveshafts turn in the same direction? If so has anyone tried to create a small gear unit attached a output shaft to reverse one of driveshafts? You'd have to flip over one of the axles as well so that all the wheels go in the same direction.

[overkillphil]

The only problem with that (besides mounting holes) is the pinion would be placed lower and in harms way.

[chops1sc]

Here is a link to my video. the first clip shows how his crawler twists vs. mine with none. You might as well enjoy the whole thing though!

http://www.rccrawler.com/forum/showt...69#post1338669

[EeePee]

The mirror mod was brilliant!

Originally Posted by mulepic

So is the true reason for the torque twist b/c the driveshafts turn in the same direction?

It's a result of the rear axle's pinion gear trying to climb the ring gear (when moving forward). Any resistance against the rear tires makes it more difficult for the pinion gear to turn the ring gear, and thus resistance against the transmission trying to turn the driveshaft. The motor tries to turn everything but can't and therefore the chassis leans over. Something has to give, and it's the left rear suspension in the Axial's case.

Dialing in suspension geometry (and other things like weight placement) will force the suspension action to counteract against those forces.