Kraton Why Do All Arrma RC's End Up Pulling to One Side?

[cageywhite]

I'm really stumped on this one. I have owned 6 Arrma RC's - Krayton 6s, Krayton 4s V2, Big Rock (2), and Granite (2). Over time, say at 20-30 packs, EVERY SINGLE RC developed a situation where they would pull to one side or the other while the car is under acceleration. It's consistently to one side (e.g. always left or right), sometimes the pull is gradual and sometimes its abrupt (like an immediate hitch or pitch to one side). Tinkering with the steering trip does not help at all. I've checked them all to make sure there bearings are clean and all the wheels turn freely. Also, on my Big Rocks, Granites, and Kraton 6s, I have upgraded the steering servo, servo saver, and steering racks (on the 3s rigs thats the part the steering servo attaches to) and they all still do the same darn thing.

Any idea what could be causing this? I was thinking about getting a new front diff for each RC, but before I do I thought I would ask. Besides, replacing the front diff every 20 packs would be lame at best, especially because I am pretty easy on my trucks (no jumps).

Any idea at all what this could be?

 

[Robbbbbb66]

I'm really stumped on this one. I have owned 6 Arrma RC's - Krayton 6s, Krayton 4s V2, Big Rock (2), and Granite (2). Over time, say at 20-30 packs, EVERY SINGLE RC developed a situation where they would pull to one side or the other while the car is under acceleration. It's consistently to one side (e.g. always left or right), sometimes the pull is gradual and sometimes its abrupt (like an immediate hitch or pitch to one side). Tinkering with the steering trip does not help at all. I've checked them all to make sure there bearings are clean and all the wheels turn freely. Also, on my Big Rocks, Granites, and Kraton 6s, I have upgraded the steering servo, servo saver, and steering racks (on the 3s rigs thats the part the steering servo attaches to) and they all still do the same darn thing.

Any idea what could be causing this? I was thinking about getting a new front diff for each RC, but before I do I thought I would ask. Besides, replacing the front diff every 20 packs would be lame at best, especially because I am pretty easy on my trucks (no jumps).

Any idea at all what this could be?

What kind of terrain/surface do you run on ?

 

[DLK83]

It's torque steer... after 20-30 packs, all the steering and suspension joints have worn and have more play/slop than they did when new.. the car will pull to whichever side has the most combined play, it tends to suck the back side of that tire in (pointing the right to the right or the left to the left) because the steering linkage is on the back side of the tire... so, your choices for a fix are deal with it, or replace everything every 30 packs..

 

[Camaroboy383]

Power, to path of least resistance.. diff fluid plays a huge roll in this.. all it takes is for one tire to increase speed over the other just a little.. also making one tire larger as well..

Torque twist can contribute as well..

 

[Moirae]

I'm surprised it took you 30 packs lol. My rigs start pulling after like 1 - 3 packs and I end up having to adjust those pivot ball things as they get loose over time. Doesn't happen as often with the on road rigs though.

 

[King blitz]

I'm really stumped on this one. I have owned 6 Arrma RC's - Krayton 6s, Krayton 4s V2, Big Rock (2), and Granite (2). Over time, say at 20-30 packs, EVERY SINGLE RC developed a situation where they would pull to one side or the other while the car is under acceleration. It's consistently to one side (e.g. always left or right), sometimes the pull is gradual and sometimes its abrupt (like an immediate hitch or pitch to one side). Tinkering with the steering trip does not help at all. I've checked them all to make sure there bearings are clean and all the wheels turn freely. Also, on my Big Rocks, Granites, and Kraton 6s, I have upgraded the steering servo, servo saver, and steering racks (on the 3s rigs thats the part the steering servo attaches to) and they all still do the same darn thing.

Any idea what could be causing this? I was thinking about getting a new front diff for each RC, but before I do I thought I would ask. Besides, replacing the front diff every 20 packs would be lame at best, especially because I am pretty easy on my trucks (no jumps).

Any idea at all what this could be?

That's so true.i have the same thing happen to me on my BR v3 I only do speed runs never bashed and I run only on ashfault .my stock servo gave out so I replaced it with the red aluminum 25kg digital servo from eBay and I noticed after a few speed passes that I have to constantly keep adjusting my stearing on the transmitter.i can get a few passes straight but like you said I'll set it up for another pass and a few seconds after acceleration it either shifts hard to one side or eventually swirvs to one side..I don't accelerate hard I ease into it so that's not the issue..seems like stearing is a huge issue with these.my buggy's have no issues.i sent the trim and stearing rate and they barely ever move ..but my big rock geez I can't figure it out.

 

[DLK83]

I'm surprised it took you 30 packs lol. My rigs start pulling after like 1 - 3 packs and I end up having to adjust those pivot ball things as they get loose over time. Doesn't happen as often with the on road rigs though.

I was going to say that as well, I'd be happy if mine lasted that long lol...

 

[cageywhite]

What kind of terrain/surface do you run on ?

Paved street, in my cul-de-sac. Or on a flat dirt and paved surface at our neighborhood middle school. Can't get any tamer than that.

Power, to path of least resistance.. diff fluid plays a huge roll in this.. all it takes is for one tire to increase speed over the other just a little.. also making one tire larger as well..

Torque twist can contribute as well..

So would the fix be draining and refilling the diff fluid? And what is "torque twist"?

 

[Velodromed]

I always figured it was my car‘s ass end looking for the best traction points on any given surface. I always think ‘good job car, well played!’

 

[Camaroboy383]

Paved street, in my cul-de-sac. Or on a flat dirt and paved surface at our neighborhood middle school. Can't get any tamer than that.

So would the fix be draining and refilling the diff fluid? And what is "torque twist"?

Yes, A diff fluid change will make a difference... An increased weight can as well.. diff fluid gets beat down fast, dealing with a lot of heat and abuse..

A 500k fluid in a center diff can "feel" like a 300k within 10 packs or so.. especially after a run with some heat in it.. food for thought..

 

[Camaroboy383]

Paved street, in my cul-de-sac. Or on a flat dirt and paved surface at our neighborhood middle school. Can't get any tamer than that.

So would the fix be draining and refilling the diff fluid? And what is "torque twist"?

Forgot to address your question of torque twist..

Torque twist occurs in the chassis.. unloading certain corners, sides, front, and rear...In different conditions / orientation of the rig of course...

Easiest way to describe is if you held a brushless motor in your hand, gave it instant full throttle, it will twist within your grip.. This torque twist will inherently try to twist the rig it's mounted to..

This is a very small fraction of what can be applied to the chassis as torque twist.. now add differing angles of torque twist from different corners of say, traction and there are all kinds of forces applied you would never think..

These cars are violent at best on every component of the drive line..

Sorry to drag you into the depths of this rabbit hole.. easier to go way back to basics, because it's a variable you can control... Change that fluid, thicken it up a hair if your not racing tracks..

 

[carckton driver]

Forgot to address your question of torque twist..

Torque twist occurs in the chassis.. unloading certain corners, sides, front, and rear...In different conditions / orientation of the rig of course...

Easiest way to describe is if you held a brushless motor in your hand, gave it instant full throttle, it will twist within your grip.. This torque twist will inherently try to twist the rig it's mounted to..

This is a very small fraction of what can be applied to the chassis as torque twist.. now add differing angles of torque twist from different corners of say, traction and there are all kinds of forces applied you would never think..

These cars are violent at best on every component of the drive line..

Sorry to drag you into the depths of this rabbit hole.. easier to go way back to basics, because it's a variable you can control... Change that fluid, thicken it up a hair if your not racing tracks..

don't forget about torque steer, which i originally thought you meant. not sure how much of an effect it has on RC cars but thats a lot of power through the driveline.

 

[Camaroboy383]

don't forget about torque steer, which i originally thought you meant. not sure how much of an effect it has on RC cars but thats a lot of power through the driveline.

Yes.. 100% relevant in the described above.. ..

 

[carckton driver]

Yes.. 100% relevant in the described above.. ..

not sure if your saying torque steer is the same as what you described or if your saying torque steer also plays a part but they are 2 different things with very similar origins.

 

[Camaroboy383]

not sure if your saying torque steer is the same as what you described or if your saying torque steer also plays a part but they are 2 different things with very similar origins.

No, Relevant to forces applied to the chassis along with torque twist as I had mentioned..

But again, the variable he will be able to control will be the diff fluid to help address the pull..

 

[carckton driver]

No, Relevant to forces applied to the chassis along with torque twist as I had mentioned..

But again, the variable he will be able to control will be the diff fluid to help address the pull..

either way i would it expect to always steer the car in the same direction unless the a motor spins the opposite way from the other. do all motors spins the same direction?

 

[Camaroboy383]

either way i would it expect to always steer the car in the same direction unless the a motor spins the opposite way from the other. do all motors spins the same direction?

Direction of the motor rotation depends on a couple factors..

Presentation of the motor to the spur..
And the gear sets..

 

[carckton driver]

Direction of the motor rotation depends on a couple factors..

Presentation of the motor to the spur..
And the gear sets..

the only thing i can see that would effect the rotation of a motor wouldnt be electrical wiring, definately polarity and maybe the direction of the windings or whatever. if you have a motor out of a car and it spins clockwise then put it in a car it will still spin clockwise. gearing and motor orientation doesn't change the direction the motor turns. question is if all motors spin the same direction, gearing and orientation isnt a factor.

 

[Camaroboy383]

the only thing i can see that would effect the rotation of a motor wouldnt be electrical wiring, definately polarity and maybe the direction of the windings or whatever. if you have a motor out of a car and it spins clockwise then put it in a car it will still spin clockwise. gearing and motor orientation doesn't change the direction the motor turns. question is if all motors spin the same direction, gearing and orientation isnt a factor.

That one clearly was misconstrued apparently...

All motors do not spin the same direction.. clockwise, or counter clockwise..

Again

presentation to the spur can dictate rotation.. (one side of the mount or the other)

Gear set's, how many gears before it gets to the output shaft will determine rotation..

Final drive gear set's.. so your differential ring and pinion.. present the ring gear to the right side of the pinion dictates a certain rotational direction of the motor... Present the ring to the pinion on the left side and quite the opposite direction of rotation..

All factors taken in by the engineering team for a final set rotation of the motor, wether it be clockwise, or counter clockwise..

Motor rotation is done electrically through the esc, or by switching two of the three wires around..


So no offense, but is this a test? Don't take that the wrong way.... cause I'm pretty sure you know electric motors can spin both directions.. They do go forward and backwards after all......

 

[carckton driver]

That one clearly was misconstrued apparently...

All motors do not spin the same direction.. clockwise, or counter clockwise..

Again

presentation to the spur can dictate rotation.. (one side of the mount or the other)

Gear set's, how many gears before it gets to the output shaft will determine rotation..

Final drive gear set's.. so your differential ring and pinion.. present the ring gear to the right side of the pinion dictates a certain rotational direction of the motor... Present the ring to the pinion on the left side and quite the opposite direction of rotation..

All factors taken in by the engineering team for a final set rotation of the motor, wether it be clockwise, or counter clockwise..

Motor rotation is done electrically through the esc, or by switching two of the three wires around..


So no offense, but is this a test? Don't take that the wrong way.... cause I'm pretty sure you know electric motors can spin both directions.. They do go forward and backwards after all......

i knew motors CAN spin in either direction just honestly didnt know if they all did or if there was an industry standard or something. BTW im only talking about "forward" direction with the same electrical input.
i don't care how many gears you put after any given motor it will always spin the same direction with the same electrical input.