Trx-4 chassis kits diff lock cable too long?

[Fiveflat]

Son and I are building our chassis kits and the diff lock cable is too long.
Photos in the instruction manual shows the servo horns in the correct position but I would have to turn the servo horn straight out at a 90 degree angle to line up with cable.

Any input on this?

 

[meatmonkey]

Not sure what your saying. Plug all your electronics in and power them up. The servo may not come out of the box precentered, but will do so once powered up with the radio on.

Dont try to remove the dinky little servo savers from the micro servos if you can at all help it. Those traxxas micro servos are easy to break, like just torque checking the bolt holding the saver on, or cycling them by hand, or unevenly prying the saver off to reposition it, can break them

 

[xagoras]

Son and I are building our chassis kits and the diff lock cable is too long.
Photos in the instruction manual shows the servo horns in the correct position but I would have to turn the servo horn straight out at a 90 degree angle to line up with cable.

Any input on this?

Are you sure you installed them correctly? They come centered from the factory and have markings on them (a little sticker) that says which is for the front and which for the rear.


Also have you secured the cable with the screw to stop it from moving around?

 

[Fiveflat]

It's hard to see in the photo but the cable doesn't retract nearly as much as the manual shows it retracted and the ball joint is pretty long compared to where the servo horn is. I couldn't move the horn either.
I was just twice shy I guess about pushing the horn over to line up with the cable after I had a fouled shift servo from something similar. I went ahead and pushed it on and it seems to work just fine. I hope I'm not straining that servo is all.

\

 

[HumboldtEF]

You can adjust the cable length a bit. The threaded brass end can be threaded in farther to shorten it.

I did a bit of investigating when the TRX4 first came out and found that these servos are happiest when the throw is equal in both directions. Its roughly 35-45° in both directions.

lots of discussion here as well as my ideas on proper adjustment.
http://www.rccrawler.com/forum/traxxas-trx-4/587415-options-replace-micro-servos-3.html#post5736593

 

[xagoras]

It's hard to see in the photo but the cable doesn't retract nearly as much as the manual shows it retracted and the ball joint is pretty long compared to where the servo horn is. I couldn't move the horn either.
I was just twice shy I guess about pushing the horn over to line up with the cable after I had a fouled shift servo from something similar. I went ahead and pushed it on and it seems to work just fine. I hope I'm not straining that servo is all.

\

The plastic end of the cable is supposed to be screwed down and locked in place.

 

[Fiveflat]

The plastic end of the cable is supposed to be screwed down and locked in place.

I understand that. It is, it's just hard to see in this photo how far off the ball joint is from the servo horn ball.


HumboltEF:
I was a little nervous about threading it too far on for fear of stripping or cracking the threaded connector.


The throw is right on the money as far as 35-45 degrees of throw from center. I just had to put a little more pressure than I thought was comfortable on the servo horn to get it to line up. Both kits were identical.

After test driving it a little I can say that it seems to be working happily so I'll run with it and see how it goes.

 

[itr1275]

These kits are basic and "shouldn't" have any issues, but they are not perfect. If you think the servo is wrong from the factory call the factory. Traxxas is good about their warranty and support.

From the picture it looks like it's at 8 O'clock and it should be more like 7 O'clock. Double check all the servos match the proper location (I made that mistake). Then make sure you have the right cable (front/rear). Call Traxxas

888-TRAXXAS*
Support@Traxxas.com
*International customers may call 972.549.3000​

 

[xagoras]

Not sure if you worked it out, but from the picture it seems that if you screw the plastic cable in place and push the diff cable all the way in, then it should be right in place to mount it on the servo horn.