M3 Help Needed!!

Forum for discussion relating to the M3 Lee nd Grant Medium Tank
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Matthew Whiteley
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M3 Help Needed!!

Post by Matthew Whiteley » Thu Dec 31, 2020 2:38 pm

Hi everyone, greetings from Ontario, Canada...

I have successfully bench tested my M3 and it runs with the tracks on both forward and back if the tracks do not touch the ground.

When the tank is sitting upright on the ground it only runs in reverse.

When I run it forward I hear a loud electronic binding noise and the sprockets won't turn.

I have added tracks, removed tracks set the tension and made sure all of my road wheels are spinning loosely.

What can I do to make the tank drive? I haven't even added the weight of the top deck yet and it won't drive forward.

Can anyone give me some advice?

Thanks, any help would be greatly appreciated.

Matthew

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Adrian Harris
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Re: M3 Help Needed!!

Post by Adrian Harris » Thu Dec 31, 2020 2:48 pm

If you can hear the electronics, there's something seriously wrong !!

With it on the ground, are you able to reach in and feel the end of the shaft in the centre of the gearbox ? Is that turning ?

Are you able to take a video and post it here ? You might have to upload it to somewhere like YouTube first.

Do you have it on single stick control or one stick for each track ?

Adrian.
Contact me at sales@armortekaddict.uk for details of my smoker fan control module and other electronic gadgetry

Matthew Whiteley
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Re: M3 Help Needed!!

Post by Matthew Whiteley » Thu Jan 07, 2021 3:27 pm

Hi Adrian,

I am currently using single stick per track. I have gotten a bit more movement out of the tank now but I will make a video and perhaps we can figure out why it doesn't seem to have much torque and what the mystery noise is.

Thanks,

Matt

Christoffer Ahlfors
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Re: M3 Help Needed!!

Post by Christoffer Ahlfors » Thu Jan 07, 2021 8:55 pm

You already tested step one: It runs well when suspended, but not on the ground.
Next step I would suggest is to remove the motors and run the track by hand to check for mechanical binding. Both suspended and on the ground.
Since everything points toward binding issues when on the ground, next step after that would be to disconnect the track and roll the tank on the road wheels to check for binding. If no binding, check the idlers for binding while on the ground without tracks, reinstall the motors and check if the sprockets run without fouling anything.
After these checks, you should have pinpointed the issue. Pls report back and we will suggest how to proceed. :D
A little too much is about right...

Pete Nash
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Re: M3 Help Needed!!

Post by Pete Nash » Tue Jan 12, 2021 3:15 am

Is it possible that the tracks are too tight?

Mark Heaps
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Re: M3 Help Needed!!

Post by Mark Heaps » Tue Jan 12, 2021 11:55 pm

The M3 has the drive sprockets at the front so it only moving in reverse would suggest to me the tracks are too loose.
Have you visually checked the sprockets are not turning or just presuming they are not as the tank is not moving. ?

Mark Heaps
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Re: M3 Help Needed!!

Post by Mark Heaps » Tue Jan 12, 2021 11:58 pm

Also did you set the track tension with the model in the air or on the ground ? It does make a difference.

Matthew Whiteley
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Re: M3 Help Needed!!

Post by Matthew Whiteley » Wed Jan 13, 2021 5:19 pm

Thanks everyone for the very helpful suggestions! I will take another look at the M3 this weekend.

I have made some progress though after fiddling with making the road wheels spin freely. The binding noise occurs less frequently and the M3 moves forward and back. It has a problem turning on one track but I will document all this in a video this weekend.

I should probably get some grease into the final drive cover. I'm embarrassed to say I didn't think to do that when building.

Thanks again for the support. What a great community of builders!

Matt

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Robert E Morey
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Re: M3 Help Needed!!

Post by Robert E Morey » Wed Jan 13, 2021 6:25 pm

Was thinking when you posted your issue - maybe the final drive gear is rubbing against hull side? This could definitely cause problems.
Best regards, Bob

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