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-   -   Tamiya TRF418 (https://www.rctech.net/forum/electric-road/750348-tamiya-trf418.html)

niznai 09-29-2014 07:31 PM

You're looking in the wrong place. Check the inboard suspension hinge pins. They're bent.

goin2drt 09-29-2014 07:37 PM


Originally Posted by niznai (Post 13564822)
You're looking in the wrong place. Check the inboard suspension hinge pins. They're bent.

Sorry when you say inboard, the long ones connecting arms at bulkhead or short ones holding c-hubs?

I have not checked those yet..

TB03Racer09 09-29-2014 07:42 PM


Originally Posted by goin2drt (Post 13564835)
Sorry when you say inboard, the long ones connecting arms at bulkhead or short ones holding c-hubs?

I have not checked those yet..

The longer ones

goin2drt 09-29-2014 07:45 PM

Thanks. I will try that tomorrow. I had to take a break ��

sosidge 09-30-2014 01:16 AM

Since the steering has no binding when disconnected, I am sure the problem is in the servo itself or the servo horn.

I see you have the Tamiya servo saver on there. One common mistake is to put the wrong servo spline adaptor on there e.g. Sanwa adaptor with a Futaba servo. That causes the inconsistent centring you mention and makes the car basically undrivable.

The other possibility is clumsy assembly of the servo saver. People have a tendency to overtighten the screw that goes into the servo which crushes the plastic and the saver binds. Another common mistake is forcing the springs on (they are difficult but precision is worth spending time on). By forcing the springs, the edges can also damage the plastic part that keeps them lined up, so you end up with free play.

Final possibility is the servo itself. I don't recognise the one you have, but some cheap brands are just... shit, basically. Loads of slop or binding in the geartrain which renders them unfit for purpose. Even a quality servo may have wear and tear or a manufacturing defect, I once had a KO servo that would only work with a KO horn, other manufacturer's horns just weren't a good enough fit. I've also seen plenty of non-Futaba servos with a "Futaba compatible" spline that were a poor fit in Futaba horns.

PDR 09-30-2014 01:29 AM

Just to continue the chain of possible issues:

* receiver malfunction
* Transmitter malfunction

You never really know until you've exhausted the whole end-to-end ;)

sosidge 09-30-2014 01:31 AM


Originally Posted by PDR (Post 13565246)
Just to continue the chain of possible issues:

* receiver malfunction
* Transmitter malfunction

You never really know until you've exhausted the whole end-to-end ;)

A loose pot in the transmitter will give a similar issue. Had it myself once many years ago.

Salkin 09-30-2014 02:50 AM

Struggled myself a little with the Tamiya servo saver, to get the little slop away.

Learned that some put a drop of superglue in the saver to keep it slop free, and the impact from a hard crash would break the glue, allowing the servo saver to operate as intended.

Guess even if the steering in itself are moving without binding, there should not be excessive slop either in the steering links, which could cause the car not center properly.

b20btec 09-30-2014 04:47 AM

You guys bring up many good points. I Went ahead and swapped out my aluminum tamiya horn to an xray servo saver and it pretty much fixed the problem.

Salkin 09-30-2014 06:11 AM


Originally Posted by b20btec (Post 13565394)
You guys bring up many good points. I Went ahead and swapped out my aluminum tamiya horn to an xray servo saver and it pretty much fixed the problem.

Just curious, the aluminium Tamiya servo horn is a solid part. Either it did not fit the spline on the servo (too big) or the ball stud attached to the end of the servo horn was loose.

Csaari77 09-30-2014 06:34 AM

Something else to consider is the amount of use on the servo saver. The plastic wears after use, especially if you are hitting things. I experienced the same problem with the servo not centering. I thought it was the servo, which i replaced with a new Futaba BLS551, but the issue was still there with the new servo. I replaced the servo saver and the issue went away. After I took the old saver off the car I noticed that the plastic had been crushed down by the metal spring collars, which was causing the steering to wander. It was an expensive lesson to learn...

goin2drt 09-30-2014 06:37 AM

Guys.

First and foremost it was working perfectly. I then had a little brush with the boards and now it is not.

I have tried a direct servo horn to eliminate any possibility with the servo saver, it's not that.
I have used two different servos, both brand new, a Savox and a Protek it does the same thing with both, not that.
I have replaced all the C-hubs and uprights, not that.

I will try the inbound hinge pins tonight
I guess it could be the radio or transmitter but that does not seem probable and will be the last thing I try as I don't have a spare just sitting around.

I have ordered a new servo saver, but I am confident that is not the issue as like I said I did just put on a regular horn, with the correct spline, and that did not fix it.

niznai 09-30-2014 08:44 AM

C'mon. It's easy to test. Just power everything up and with the steering dead straight (as much as you can) grab a wheel and pull it hard around. Watch what happens. The car will tell you.

b20btec 09-30-2014 09:53 AM


Originally Posted by Salkin (Post 13565530)
Just curious, the aluminium Tamiya servo horn is a solid part. Either it did not fit the spline on the servo (too big) or the ball stud attached to the end of the servo horn was loose.

Its actually fit perfect, along with the ballstud, and 3mm screw. I believe the problem occurred when I removed it to swap servo. I knew it was going to be a pain to get off, when I got it back onto the new servo that's when the play came about but didn't realize it until I did a swap for a xray saver.

I said earlier in a post I gave up, but I was setting up the car for outdoor track I wanted to install a servo saver. Anyways it came off a lot easier than before, that's when I knew. Putting it on the setup station for throw before and after pretty much confirmed it.

Sanwa ers-971
Xray saver

niznai 09-30-2014 09:56 AM

You guys in the US have the Kimborough servo savers which are a cheap reliable alternative to the expensive Xray option (and the expensive, crappy Tamiya option).


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