Eliminating torque Twist - opposing trans outputs?

[simon170]

Ok, so I'm planning a build at the moment and I want ZERO torque twist (it drives me crazy! lol)

I seem to remember reading somewhere that if you had a transmission/transfercase with opposing direction outputs, it would cancel out an torque reaction from the motor. I should imagine that you would have to flip over one of the axels to keep things going in the right direction.

I have looked around, but cant seem to find any information on said idea or if there even if such a trans exists.

Does anyone know anything about this? Any info welcome

Thanks

[dieselfuel]

eliminating torque twist in 2 easy steps...

1. buy MOA
2. enjoy

sorry, i bring nothing to the table.

[simon170]

LOL, thanks for looking...

MOA is not an option for me I'm affraid.

[poorboyrc77]

Originally Posted by simon170

Ok, so I'm planning a build at the moment and I want ZERO torque twist (it drives me crazy! lol)

I seem to remember reading somewhere that if you had a transmission/transfercase with opposing direction outputs, it would cancel out an torque reaction from the motor. I should imagine that you would have to flip over one of the axels to keep things going in the right direction.

I have looked around, but cant seem to find any information on said idea or if there even if such a trans exists.

Does anyone know anything about this? Any info welcome

Thanks

You're planning a build but you don't tell us what you're planning to build.That makes things kind of hard to answer.

[simon170]

Originally Posted by poorboyrc77

You're planning a build but you don't tell us what you're planning to build.That makes things kind of hard to answer.

I'm planning on building a capable scaler, with a Reign K2-5 chassis and Axial running gear, long shocks, looking for loads of articulation etc.

Didnt mention it as thought peeps would just be talking trannys...

[oldhippie]

I don't think your theory is sound:?

[simon170]

Oldhippie: Its something I read a while back, I'm just checking to see if its a well known practice or something that was just a theory. The idea seems to ok in theory, just dont know if someone has done it, or if there is such a tranny.

[littleskull99]

Twinset on this board and Eggressor I believe have both come up with counter rotating transfer cases. Il see if I can find them......

Belt Buckle Crawler (no pics tho its an old thread)

http://www.rccrawler.com/forum/showt...light=transfer (newer one)

[Manning]

Torque twist is worst going up or down steep hills.

When going up or down steep hills, the majority of the weight and therefore traction is on the downhill tires, and very little weight and traction is on the uphill tires.

Since nearly no weight and traction is available on one of the axles, there's little or nothing for the counter rotating axle to counteract.

Bottom line, you'll still have torque twist. Just preload the driver's side rear shock (for going up hills) and passenger side front shock (for going down hills) and be done with it.

[simon170]

Littleskull: thanks very much for posting those links mate, was beginning to think I had dreamed it! lol makes for very interesting reading. Is Eggressor still selling these?

I also found this: http://www.rc4wdstore.com/2/product_...roducts_id=545 would this do the trick if the right shaft was used for the input drive?

I read that the Axial axel might be troublesome for this, as there are no mounting points for the top link once flipped over.

[littleskull99]

Originally Posted by simon170

Littleskull: thanks very much for posting those links mate, was beginning to think I had dreamed it! lol makes for very interesting reading. Is Eggressor still selling these?

I also found this: http://www.rc4wdstore.com/2/product_...roducts_id=545 would this do the trick if the right shaft was used for the input drive?

I read that the Axial axel might be troublesome for this, as there are no mounting points for the top link once flipped over.

That will work as it is 1:1 ratio. The input can attach to either shaft. Which means you can run it counter rotating driveshafts or same direction. You will have to experiment flipping front and rear axles to see which gives best results, One way round may add to the troubles. Youl only be able to flip the front axle if the steering will be chassis mounted beacuse it needs servo posts cutting off etc.
Most torque twist can be dialled out with link geometry and shock setup.

Matt

[simon170]

Do you think its more hassle than its worth?

[SACCO]

Yes

i even tried the whole 2 tranny idear with one axle flipped. Didnt help much, and was too heavy in the belly with 2 motors in there

[Offroader5]

Originally Posted by littleskull99

That will work as it is 1:1 ratio. The input can attach to either shaft. Which means you can run it counter rotating driveshafts or same direction. You will have to experiment flipping front and rear axles to see which gives best results, One way round may add to the troubles. Youl only be able to flip the front axle if the steering will be chassis mounted beacuse it needs servo posts cutting off etc.
Most torque twist can be dialled out with link geometry and shock setup.

Matt

This cannot be used to counter-rotate one shafts vs. the other. You would need a two gear tcase so that one gear rotated opposite of the other. The RC4WD tcase is a 3 gear design meaning the two outer gears will always rotate the same direction.

[JeremyH]

Originally Posted by simon170

Ok, so I'm planning a build at the moment and I want ZERO torque twist (it drives me crazy! lol)

I seem to remember reading somewhere that if you had a transmission/transfercase with opposing direction outputs, it would cancel out an torque reaction from the motor. I should imagine that you would have to flip over one of the axels to keep things going in the right direction.

What you were reading was most likely referring to a 1:1 vehicle, where the motor is mounted in 1 position and the tranny/t-case in another. The motor is fixed, but the t-case can be changed.

This is not the case with a 1/10th RC. We use transmissions/t-cases that have the motor DIRECTLY mounted to the unit. If you flip the transmission around, then you'll simply move your torque twist from one side to the other because you are changing the direction the motor rotates. Even if you flipped around your motor/tranny/t-case, you do not need to flip an axle...you can change the polarity of your motor by either switching the wires or flip the switch on your Tx.

The best modification to eliminate torque twist on a vehicle running Axial axles is to install a set of overdrive diff gears in the front axle:
http://www3.towerhobbies.com/cgi-bin...I=AXIC3401&P=K

These will turn the tires slightly faster in the front than in the rear. To date, this is the best modification that I have found to eliminate torque twist. It wont, eliminate TT in reverse...

Hope this helps.

[miller]

Originally Posted by JeremyH

What you were reading was most likely referring to a 1:1 vehicle, where the motor is mounted in 1 position and the tranny/t-case in another. The motor is fixed, but the t-case can be changed.

This is not the case with a 1/10th RC. We use transmissions/t-cases that have the motor DIRECTLY mounted to the unit. If you flip the transmission around, then you'll simply move your torque twist from one side to the other because you are changing the direction the motor rotates. Even if you flipped around your motor/tranny/t-case, you do not need to flip an axle...you can change the polarity of your motor by either switching the wires or flip the switch on your Tx.

The best modification to eliminate torque twist on a vehicle running Axial axles is to install a set of overdrive diff gears in the front axle:
http://www3.towerhobbies.com/cgi-bin...I=AXIC3401&P=K

These will turn the tires slightly faster in the front than in the rear. To date, this is the best modification that I have found to eliminate torque twist. It wont, eliminate TT in reverse...

Hope this helps.

The theory is that your rear shaft spins the opposite direction of the front in which case you would need to flip one of the axles in order for them to run in the same direction. The result is that the torque transfer is then canceled out. Great theory...would love to see it on an actual crawler doing something steep.

[JeremyH]

Originally Posted by miller

The theory is that your rear shaft spins the opposite direction of the front in which case you would need to flip one of the axles in order for them to run in the same direction. The result is that the torque transfer is then canceled out. Great theory...would love to see it on an actual crawler doing something steep.

Yes, however, if you flip the tranny around, your front driveshaft will also spin in the opposite direction.....resulting in your truck simply running backward. No need to flip an axle....simply flip the reverse throttle switch on your Transmitter.

[soundcolor]

Torque Twist is not a product of which directio the motor or driveshafts spin.
It is simple a representation of weight transfer. The tires dont know where the pinion is, or which way its rotating, all they know is the amount of torque/power being applied to them.

Having a counter rotating driveshafts wouldn't make a diffrence, because at the end of the shaft is the pinion... upside down or rightside up doesn't matter, the tires are still going to spin in the same direction. The pinion is going to see the same forces, they transfer the same forces to the ring gear, out the axles and on to the tires. The tires are gonig to hook up in the same way when power is applied to them, causing the weight of the vehicle to transfer rearward, the fact that the tires have traction and are moving the same direction means that you will still have the same TT with any kind of shaft drive you have.

[littleskull99]

Originally Posted by Offroader5

This cannot be used to counter-rotate one shafts vs. the other. You would need a two gear tcase so that one gear rotated opposite of the other. The RC4WD tcase is a 3 gear design meaning the two outer gears will always rotate the same direction.

I beg your parden, You are correct. I thought it was a two gear trans.

[JeremyH]

Originally Posted by soundcolor

Having a counter rotating driveshafts wouldn't make a diffrence, because at the end of the shaft is the pinion... upside down or rightside up doesn't matter, the tires are still going to spin in the same direction.

Yes, if you flip the tranny around, then the motor is now facing the opposite direction...meaning the pinion will spin in the "opposite" direction with relation to the chassis. You are correct that it will simply change your TT from one side to the other.

Like I said earlier, the best method of eliminating TT is to install the overdrive gears in the front axle. Those gears have damn near eliminated the TT in my axial...