On the transmitter that came with my HL tiger 1 with the trim in the center postion and the stick centered the tracks run in reverse. To set it so the tracks do not run in either direction and with the stick centered I have to position the trim tab to the very top. How can I reset it so when the the tracks do not move in either direction when the trim tab is in the center and stick is in the center?

Good question, no real answer.
Consider: The trim on the xmitr is there to bias the signal throught the pot on that axis of the joy stick, but the question is why? In your case (and in mine the right stick trim is althe way up to stop reverse motion with zeroed stick), so , either the xmitr is sending too strong a signal (to many encoded pulses) for the resistance in zeroed position, or, more likely, the h-bridge in the driver circuit for the motors is out of balance. They use cheap electronics, which could mean leaky transistors (quite common).

I'm thinking, maybe the cheapest tac to start with would be to try another driver board. The transistor bridge is a simple circuit, but for me, without schematics, fixing that would be quite a task.

No help, but maybe food for thought?

splat

your lucky my non s&s tiger trims dont even move theyve glued them down at the factory []
cant you remove the front panel and adjust the trims that way?
anyone open up there transmitter??[X(]

On the non-smoke and sound models,there is no trim adjustment. BIGMIG

they went to the hassle of putting the lever on but no adjustable trim lmao
must be all those lead fumes i suppose

the trim tab for the forward and reverse works on the S&S versions. Would be nice though if when in the stopped position on the main stick the trim tab was also in the center position is all. I was wondering if I was to solder a small trim pot in series to the one lead and center the trim lever then adjust the trim pot till the motors stop this might give full use of the trim lever

Yes, you could. You would, in effect, be moving the trim function to the pot that you added, BUT... You may have created a situation where yout trim tab on the xmitr is back to center, but that is only cosmetic! You are still biasing the joystick pot's output to compensate for mechanical or electrical defect. When you apply that bais, you lose effective range of the joystick throw (you can add so much bias (or 'trim') that you won't get any response from the joystick in that axis).

You would also be unbalancing the that axis of the joystick. I don't think that the trims are in series, I think they are in parallel to add or subtract (add pos or add neg) bias voltage. You would just be contributing to the problems.

Better to determine the reason that the h-bridge on the driver circuit is not zeroed when the joystick on the xmitr is centered.
If it is really that big a deal to you, or if you lose function in that axis, my first suggestion is to try another driver board, or find a hameture radio guy who is willing to trouble-shoot the driver board and xmitr and maybe fix it.

more likely, just live with it.

Splat

I think you are right there is an old saying if it's working .... leave it alone