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Forward or reverse rotation Traxxas 21t?

ik632

RCC Addict
Joined
Dec 22, 2011
Messages
1,439
Location
Raleign
I'm going to pick up a 21t Titan Traxxas motor for back up for a trip we're taking and wanted to know which rotation to get. I think there's a little bit of advanced timing, so not the best idea to just swap the wires and run in backwards.

I have searched and most people say they are running the motor, but no indication of which rotation direction it is. Thanks. "thumbsup"
 
Stock Wraith needs a clockwise rotating motor(=reverse). Most people swap the diff around so they can fit a "normal"rotating -Counter Clockwise, that is- , motor. There are quite some extensive threads on that.
 
Just look at your truck now and spin the spur gear by hand.. when your spinning it the way that makes the tires spin forward, observe the direction your motor is spinning.. if the motor spins CW than get a reverse rotation motor. if its CCW get a normal motor.

95% of motors sold are Counter Clockwise Rotation, this is considered normal. Reverse rotation is clockwise. My wraith was already setup for CCW rotation so I just used a regular Traxxas 21t. I feel its better to swap your diffs and be able to run all the "Normal" motors, than to always have to search for Reverse rotation motors.
 
Just look at your truck now and spin the spur gear by hand.. when your spinning it the way that makes the tires spin forward, observe the direction your motor is spinning.. if the motor spins CW than get a reverse rotation motor. if its CCW get a normal motor.

95% of motors sold are Counter Clockwise Rotation, this is considered normal. Reverse rotation is clockwise. My wraith was already setup for CCW rotation so I just used a regular Traxxas 21t. I feel its better to swap your diffs and be able to run all the "Normal" motors, than to always have to search for Reverse rotation motors.

Yes, I built kit per instructions and I run the Traxxas 21T counterclockwise rotation. "thumbsup"
 
So could this explain why my titan 12t motor doesn't run anymore? Stopped all of a sudden when it rolled on it's back. When I got the wraith, forwards was backwards on my radio and vise versa, I swapped the wires and was on my way. I take it wasn't right thing to do?
 
The 12t is a higher strung faster motor than the 21t. My guess is you may have used the usable life out of it. Or, you could have popped off one of the leads. They can pull of the solder tabs pretty easy. Take a peak through the end and see if the brushes are still good.
 
I will check the leads for sure. I was pretty shocked to find it to stop running all of a sudden, I would imagine there is a wind down effect when the motor burns out.
 
Running a 21t titan in my lil boy's rig, standard rotation. Honestly don't remember if I swapped motor wires or not. Couldn't care less if it dies early, got a spare in a bag waiting. The thing is powerful enough for him on 2s.
 
I was running a 3s since that is all I have actually. Was a blast in the dirt but left me wanting more on the straights.
 
So, when I look at the back of the motor (from the rear of the truck) and the truck is rolling forward, the motor is turning clockwise.

When I look at the pinion/spur (from the front of the truck) it is turning CCW.

Does this sound like the prior owner flipped the diffs?

If that's the case, then I just need a regular motor and I'm good to go.
 
Did some more research and will answer my own question in case someone else stumbles across this.

Standard Motor Rotation = CCW when looking at pinion
Reverse Motor Rotation = CW when looking at pinion

So, in my particular truck (which I got used) if I roll the truck forward and look at the fan in the motor turning I can see it's turning from driver side towards passenger side, or CCW when looking at pinion. So, my suspicion is that the prior owner flipped the diffs to run it with standard motors.
 
The motor issue will also only come into play if using a "timed" motor. Many crawler motors come set at 0 degree timing. So you will not hurt anything or have any performance issues just swapping motor leads, etc.

But if it is a Timed motor with some advance timing set in it. And you reverse the esc or swap the motor leads, the motor will be running with retarded timing (when going in forward). Harder on the motor if not just crawling (harder on it then too). but if you do a lot of high speed then the motor will get hot quick. On a timed motor you can swap the leads and it will change direction. But if it was set with say 10 degrees advanced timing, it will now be set with 10 degrees retarded timing. No one runs that. Only advanced (at least in normal rc vehicle use) is used. Many 27 turn motors come with a set timing that you can not change for racing applications. They make them that way so people can not mess with timing to get an advantage. Advanced timing can make the motor more powerfull at the expense of some efficiency.

If running a rig and it has positive timing on the motor and you have the radio set to normal non reversed for esc and the esc hooked up with its positive wire to the positive wire on the motor and it goes backwards. Then swap the diffs. It will now travel in the correct direction and the motor will be set up right and not over work. It is easy in the Wraith and not many vehicles give you the option to do this.
 
Got myself confused, fitted up a Traxxas 3975R Titan which is the reverse rotation motor. With the motor leads normal the Wraith went backwards, so reversed the leads and its running fine. Is it ok to keep running it like this? Or should I flip the diff gears and correct the motor leads ? I thought that buying the reverse motor meant I would not need to alter the motor leads and it would run the correct way.
 
Got myself confused, fitted up a Traxxas 3975R Titan which is the reverse rotation motor. With the motor leads normal the Wraith went backwards, so reversed the leads and its running fine. Is it ok to keep running it like this? Or should I flip the diff gears and correct the motor leads ? I thought that buying the reverse motor meant I would not need to alter the motor leads and it would run the correct way.

You should reverse the wires on the motor back to how it came and flip the differential ring gears to the opposite side in the axles. Or buy a Traxxas 21 turn Titan 550 motor...p/n 3975:

TowerHobbies.com | Traxxas Titan 550 Motor 21T E-Maxx

These motors have some timing advance running opposite direction they are slower and will burn out sooner.
 
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