Tamiya QD Trailmaster truck side rotating knob purpose

[KEV THE REV]

Does anyone know the purpose of the rotating switch knob thing on the side of the frame opposite the on / off switch ?. I'm trying to get the truck working as it's pretty much dead , and wondered if the rotator is suspect . I wondered if it is some kind of speed resistor dial. Cheers. 

[wolfdogstinkus]

I did have a couple of these years ago but don't remember the thing you speak of?

I ripped all the original stuff out and made it brushless.

Not as much fun as the "monster" range but a tough little truck.

[KEV THE REV]

Thanks for the reply.  I saw your modded truck , looked to be rapid . I've attached a couple of pics of the dial switch rotor thing . I've stripped the PCB etc out now to replace with 2.4g radio , ESC etc , but still interested to know what the dial did .Cheers and thanks again 

 

[wolfdogstinkus]

I think I may remember that now, I'll have a hunt around to see what information is out there. 

I thought this would have been better if it was 4wd, it looks a lot like a toy TXT 1.

But I didn't see an easy way to make it 4WD back then. I don't have any of these trucks anymore, just didn't enjoy it as much as the monster range.

[KEV THE REV]

Thanks again . I'm modding it to use 2.4g radio. I've changed out the steering servo and now working on the radio box to fit in the esc etc . I'll just get it running for now and maybe later upgrade the motor . 👍

[wolfdogstinkus]

The stock motor will wake up a bit on 3s, I'm sure. 

You don't need to mess about with pinion mesh either then. I don't remember exactly how the motor mounts in these but if it has the plastic locating pins, leave them in place and drill one more hole to line up with the motor and that should be enough to keep it in place and again without disturbing pinion alignment.

 

Make a cardboard template with all the motor holes, place it over the locating pins and drill a hole to mount the motor.

[KEV THE REV]

Thanks for the info . I'm looking for a battery door for this truck , you wouldn't have one lying around still would you ? Anything useable will be great , cheers. 

[wolfdogstinkus]

Sorry, no. I had 2 trucks years ago but all long gone now.. just go lipo.

[KEV THE REV]

Ok. Thanks again 

[wolfdogstinkus]

Found some really old pics of my trailmaster recently and thought of this thread, I did look for the purpose of that knob but never found out.

I suspect that this is the reason I didn't enjoy this truck as much as I should have.

I see why they call them blue bottle motors, had the same power as a small housefly. Don't remember the brand but it was pretty slow.

Good luck with your one.

 

[Mokei Kagaku]

On 9/26/2023 at 3:01 PM, KEV THE REV said:

Does anyone know the purpose of the rotating switch knob thing on the side of the frame opposite the on / off switch ?. I'm trying to get the truck working as it's pretty much dead , and wondered if the rotator is suspect . I wondered if it is some kind of speed resistor dial. Cheers. 

It's a potentiometer for the steering trim, which is kind of strange considering that the transmitter that came with the Trailmaster has both steering- and throttle trim. 

[Saito2]

1 hour ago, Mokei Kagaku said:

It's a potentiometer for the steering trim,

I was going to guess this but knew nothing about the truck, so kept quiet. I had an "internal" bet going with myself, lol. Thanks for solving the mystery.

[KEV THE REV]

11 hours ago, Mokei Kagaku said:

It's a potentiometer for the steering trim, which is kind of strange considering that the transmitter that came with the Trailmaster has both steering- and throttle trim. 

Thanks for the replies and info. I thought it was some kind of resistor / speed limiter ,  and as you say the controller already has steering trim so I ruled that out . The old PCB and sundry items / servo have now found a new home in the bin .