Ronan87

Took into position of a HL Panzer IV... it's been... difficult lol

After basically having to gut it i still have one issue... the tank refuses to go straight!

Symptom:
The left track starts to turn ONLY after a short delay of the right track starting to turn. Left track also turns slower = the tank can't drive straight.

What i tried:
I switch remote, switch receiver, switch RX-18 and tried different crystals and a new battery.

To be noted:
I noticed the left gearbox shaft has about 2mm of play. I put a shim and it didn't change anything...


What can be wrong? Issue with the wire/plug? Motor? gearbox itself?

It is the standard plastic gearbox (waiting on a new/better metal one), so is that 'normal' that it doesn't work properly?

I could really use some help, my better half CAN'T wait to try her new tank...

BIGMIG

WoW.........Did you try adjusting the trim lever for motion control ??............sounds like you tried everything except a different transmitter...? Could be that also.....it's possible.


BIGMIG

P.S. a simple test also would be to switch the motor leads to see if the problem moves to the other side.

Had a second thought on this (if you switch the motor leads and now the oposite motor is having this problem...i think it would have to be the boards or transmitter.) But one does not see very many problems with transmitters posted here.

If you switch the motor leads and the same side still does the same thing then it may well be in the motor or the gear box is very tight.
Sometimes the plate on the side of the gearbox where the motor is mounted gets bent in toward the top and puts to much pressure on the pinion against the gear and could cause this.You want good contact,but no pressure on the gear.

For what it's worth.....

BIGMIG

Ronan87

I just tried:

Different transmiter.
Different receiver.
Switched the motor leads.

Issue stay's on the left side (it didn't jump to the other side).

:/

BIGMIG

Well it pretty much has to be the motor or gearbox...or the plate on the side of the gearbox where the motor mounts could be bent inwards and causing the pinion to become pressing to hard against the gear....i have seen this happen........beyond that i don't have a clue [:-]

BIGMIG

Ronan87

What i don't understand... is why the left motor has 1-2 second delay before starting to move... they should both start at the same time right?...

BIGMIG

They should..........

With all things involved in the movement of the tank being equal in theory......

One track being a lot tighter than the other....stiff road wheel or wheels on one side......stiff idler....also a problem...????

Ronan87

Hmnn i ruled out electric issue (could still be motor of course) since i swapped all the electronics.

Pah co chu puk

I noticed the left gearbox shaft has about 2mm of play.

What i don't understand... is why the left motor has 1-2 second delay before starting to move...

I think these two issues are related.


Check the set screw that holds the final gear on to the output shaft. When the set screw on my Panther losens up one track will seem to start later than the other one even though the motors are running the same. The shaft will spin inside the gear with the set screw giving just enough power to move the tank. It will run in circles then too.

If there is no set screw then it is a friction fit and may be worn and lose.

FreakyDude

Ronan  The motors are not matched sets on those plastic gear sets, If you change the plug ins on the RX18 it will tell you for sure if it is a motor problem ( A bad motor will be slow regardless of RX18 plug location )

Ronan87

I will try to switch the motors tomorrow. If switch the left one to the right and the issue moves to the right gearbox... then it's the motor! (And i'll contact Freaky ).

thecommander

Does this delay exist with the tracks disconected/removed? The idlers or road wheels may be fouled or adding resistance. You may also want to try removing the motors from the TUs. See if the delay is still present at the motors w/o the load of the TU gears or the track system. Rotate the TUs by hand with and w/o the motors with the drive sprockets only in place. Elvaluate how much drag is present on the left as compared to the right. Do they both sound the same under power? Put a cardboard tube (like a paper towel roll) to the TU and your ear one at a time and listen for howling/grinding. The pinion gear lash may be set too tight.

I wish you were closer I send you some to try out. Let me know how you make out.....Bob

1sgt

Don't drink so much beer then. LOL just kidding. I agree with some of the other posts. It could be the gear box frame or gear shaft is bent a little, or the road wheels causing to much friction. See if all the road wheels turn feely and look at the gear box frame.
Be careful on testing though, I had a bent gear axle on my Panther G and it caused the board to fry. House smelled of burnt electronics for a week.

Jim

Ronan87

Took the tracks off, and i noticed both gearbox starts almost at the same time, BUT, the left one starts slightly after and doesn't turn as quickly.

Ronan87

New steel gearbox in. Works perfectly!

thecommander

Both gearboxes should sound the same. Try breaking them in by running them slowly (lower voltage) with some Permatex valve lapping compound from an auto parts store ONLY ON THE FACES OF THE GEARS. NOT near the shafts or bushings. Apply sparingly and run them slowly for a hour or so outside of the tank. Clean them, lube them and evaluate assess the improvement. Repeat if necessary. Lube the shafts and bushings with machine oil and the gears with a thicker grease. I use white lithium. No WD 40. Then cover the TUs to keep oil in and the dirt out.