Tekno issues

[Ramp addict]

The steering on my daughter Tekno MT410 sucks.

Sitting still the steering is fast and full range.
Backwards the steering is fast and full range.
Forward the steering is slow, range is about 10 degrees, and the servo struggles.
Wiggle the steering wheel back and forth a few times with the truck sitting still and everything frees up.
Sitting on the ground with the wheels off, no changes.

Replaced the sevo, no change.
Rebuilt the bellcrank, no change.
Installed a Castle BEC, no change.
Replaced the C and steering blocks, no change.
Replaced the driveshafts, CVs, and axles, no change.

The drive cups are heavily worn, could the dog bones be binding in the cups?
New drive cups have been ordered.

I'm running out of ideas.

 

[tntpoof]

not sure what servo you got my my brain says its still servo.Servo is weak in air nor resistance in rev same . put in fwd then you have major stress in turning...
take servo out and test it like bill has done on rc groups he put servo in wooden jig with servo tester attached . a weight at floor and had servo pull weight off the ground

 

[WickedFog]

Wonder if the Rx is bad

 

[requiem33]

Post the info on the servo you have.... Make, model... specs if you have them that'll save us having to look it up.

 

[Ramp addict]

2 servos.
Yeah racing 33kg.
Reefs Raw 500.
I also ran it off of a Castle remote BEC at 8v, no change.
I've also replaced all the ball ends on the truck.
The idea of swapping the drive cups left to right I think would be a good test to see if I'm on the right track. After dinner I'll be on it and we'll see where it goes.

 

[requiem33]

2 servos.
Yeah racing 33kg.
Reefs Raw 500.
I also ran it off of a Castle remote BEC at 8v, no change.
I've also replaced all the ball ends on the truck.
The idea of swapping the drive cups left to right I think would be a good test to see if I'm on the right track. After dinner I'll be on it and we'll see where it goes.

The Reefs Raw 500 should be great in that MT410. Have you checked the servo arm? Pull it and check the splines and also just make sure it's attached good and the screw is snug holding the servo arm to the servo. Might check the splines on the servo while the arm is off too.

 

[Ramp addict]

Swapped the drive cups and it did nothing.
It only does it when driving forward, sitting still or going backwards the steering is just fine.??

I installed her receiver in my Sledge for tomorrow. With any luck she'll take a liking to it, that'll solve the problem. It's pimped to the hilt and faster than hell so she shouldn't have any complaints. Well, it is lime green, she may complain about that.

 

[RustyUs]

What transmitter and receiver do you have to control your MT?
Anytime I have weird servo issues, and no binding is found in the linkage/bellcranks, I will swap channel 1 & 2 plugs on the receiver. This will let you control the steering with your transmitter's trigger, and control the throttle with the transmitter's wheel. Just keep the RC off the ground until you verify ESC has a neutral signal.

 

[tntpoof]

I've had similar issues with a sct years ago.it was a failing bec on the esc..but you have a castle bec installed so that kills that idea

 

[WickedFog]

I've had similar issues with a sct years ago.it was a failing bec on the esc..but you have a castle bec installed so that kills that idea

I was thinking that as well. If it isn't a binding issue, could it be the receiver having an issue delivering the voltage to the servo when under throttle load? That's the only thing I could think of.

 

[Ramp addict]

The stock radio system from my Sledge.

I installed her radio system in my Sledge this morning so sho would have something to drive today. Now my Sledge does the same thing.

With it's symptoms it seemed like a mechanical problem or potentially an electrical issue, I would have never thought to blame the radio system.

 

[WickedFog]

The stock radio system from my Sledge.

I installed her radio system in my Sledge this morning so sho would have something to drive today. Now my Sledge does the same thing.

With it's symptoms it seemed like a mechanical problem or potentially an electrical issue, I would have never thought to blame the radio system.

Seems to me the only thing it could be is the receiver might not be delivering the full voltage under throttle load. Unless it's a weird problem with the transmitter.

Buy a Flysky GT3B. They're cheap, and really good radios for the money.

 

[Weezel]

The stock radio system from my Sledge.

I installed her radio system in my Sledge this morning so sho would have something to drive today. Now my Sledge does the same thing.

With it's symptoms it seemed like a mechanical problem or potentially an electrical issue, I would have never thought to blame the radio system.

Have you tried resetting the radio? I've had to do it before to fix odd issues. Is this a TSM receiver?

Seems to me the only thing it could be is the receiver might not be delivering the full voltage under throttle load. Unless it's a weird problem with the transmitter.

It acted the same with using a separate BEC so not sure about how it's a voltage thing? The positive pins and the negative pins are usually connected on a bus-bar setup.

 

[WickedFog]

Have you tried resetting the radio? I've had to do it before to fix odd issues. Is this a TSM receiver?


It acted the same with using a separate BEC so not sure about how it's a voltage thing? The positive pins and the negative pins are usually connected on a bus-bar setup.

I am just thinking something in the Rx is not letting enough amperage to pass through, like maybe something has gone bad on the Rx pcb.

@Ramp addict - has the car been wet?

 

[9x19]

Interesting problem... glad you figured it out.

My FlySky GT5 has been a good radio for me so far.

 

[Ramp addict]

I replaced the receiver today and the truck works perfectly. I read the directions before installing the receiver (TQI) and discovered I was running the BEC voltage too high.

Now that the front end has been rebuilt I've ordered the parts for the back end. The Princesses personal ride will be premo when I'm done.

Thanks for all the suggestions. I'm happy to get the truck back on the road.