track movement

Forum for discussion relating to the British MK IV Tank
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Martin Taylor
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track movement

Post by Martin Taylor »

After much struggling (and invaluable help from a close friend and chain drive expert??) I have at last managed to fit the tracks, encouraged by Mark's assurance that it was possible to do so without having to dismantle the front idler assembly and re-profiling the adjustment trays. Obviously there is no further adjustment to lower the track tension so it was not an entire surprise that even with the tank jacked up to minimise friction on the tracks, the motors will not turn beyond taking up the minimal slack in the initial drive chains. Has anyone else hit this problem and/or has helpful suggestions?? :?
Thanks in advance!
Martin

Daniel Scholefield
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Re: track movement

Post by Daniel Scholefield »

I couldn't even join the chain links until I got the adjustment trays altered to allow the front sprocket to go fully back, totalling my first tensioner tool in the process and I do not think I am alone in that!
Since it seems that you managed to join the chains without doing that it must that you have too much tension/friction in the chain for the motor to overcome. The chains will slacken off with use but if they don't move now then that won't be able to happen.
Only solution I know of is to reprofile the trays, then it all becomes so much easier to fit and run. Speaking from personal experience it is worth the hassle of disassembling the front axle one time to do the fix.
Mark IV No. 35 aka. L9 Lightning III
Hetzer No 28

Steve Stuart
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Re: track movement

Post by Steve Stuart »

M ha'p'orth is to agree that a bit of re-profiling now will mean that you will be taking tension out of the system and solving a lot of problems.
The chain links will wear and bed in, but that is in the future, but until then there is not quite enough slack with out taking that little bit of material away, and there is quite a lot of friction in the system until things wear in a little. I found a fait amount of 'swarf' being generated as the tracks turned owing to their rubbing in various places. I have taken the tracks off once in the installation process and then once again since.
The tracks will be taken off in the spring when I can face the job, it will be interesting to see what wear has taken place and if any additional rubbing strips need to be installed. The delay is to ensure that enough running will have taken place to get a fair idea of how it has bedded in.
Have fun!
Steve

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Chris Hall
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Re: track movement

Post by Chris Hall »

What Daniel and Steve said.

While I don't wish to gainsay Mark's advice, I really think the best way is to file out some metal from the front trays. It's an easy job with a file and a bit of measuring, and doesn't detract from the final look.

At the moment, it sounds like you're in danger of burning out your motors.

Good luck !

Chris
Mark IV (Liesel, Abteilung 14, France 1918)
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Armortek
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Re: track movement

Post by Armortek »

Hi Martin

What the guys are saying about filing the trays and allowing more movement of the idler, to give less tension is true. However, that is not your problem. These motors and gearboxes have plenty of torque to overcome massively excess tension. If your tracks don't move its because the speed controller is detecting an overcurrent and turning them off. Something, somewhere in your build is jammed. You need to take the tracks off and clear the obstruction before trying again. By all means modify the trays while you do this, it will make re-assembly easier, but too much will cause the idler itself to jam.

Mark
Armortek

Martin Taylor
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Re: track movement

Post by Martin Taylor »

Thanks gentlemen! Mark was (not surprisingly) correct in advising that I could get the tracks on and he has already kindly offered to re-profile the adjustment trays for me if the tension is too great.. I was really clutching at straws in asking whether there was a simpler solution that avoided the need to dismantle and rebuild.It is clear from the consistent messages via the Forum that there is really only one way to go! :)
Thanks again guys.
Martin

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