Tamiya KT track issue

[Awins]

Can anyone explain why my KT can turn tight circles on a hard floor surface, but over soil and grass it just slowly turns direction. This happens while travelling in both forward and reverse directions.
I often have the links break too. The tracks do not appear to be over tight. This KT has been built straight from the box as per the instructions supplied with no modifications having been made to it

Thanks guys

[jackalope]

It sounds to me like either the battery is weak or if that's not the case my next guess would be there's just not enough torque coming out of the gearboxes to turn it once it encounters some resistance such as grass or dirt.

Now mine isn't a Tamiya but I recently upgraded my motors to high torque ones and now mine can do 360 spins in foot deep grass! True I'm also running 4.1 gearboxes and have reinforced hull mounted output shaft bearings so it can handle the torque.

[billpe]

It's just the way the Tamiya DMD works - it won't properly pivot turn by design so the gearboxes don't get stressed out. I believe that the more resistance offered the wider the turning circle will be as the inside track is run proportionally to the outside track, a bit like a diff. Even on the 540's I have on my Russian uber gearbox, it does wide turns.

As for the tracks breaking - what are you running it on? Have you checked that the wheels, sprocket and idler all align? The tracks should have some slop in them. They are the weakest component in the drive train so tension will harm them.

[Awins]

It's just the way the Tamiya DMD works - it won't properly pivot turn by design so the gearboxes don't get stressed out. I believe that the more resistance offered the wider the turning circle will be as the inside track is run proportionally to the outside track, a bit like a diff.

As for the tracks breaking - what are you running it on? Have you checked that the wheels, sprocket and idler all align? The tracks should have some slop in them. They are the weakest component in the drive train so tension will harm them.

The tracks seem to break links while running over grass. The grass is short and I feel that the ground condition wouldn't really be to much for the KT

[billpe]

That's not right - I would say check the drive train for alignment and loosen the tracks.

[tomhugill]

This is very strange, my experience of Tamiya electronics is completely different, on my Tamiya king tiger and Panther etc the Tamiya dmd/MFU combo were one of the only electronics packages that stopped the inside track and allowed tight turns, I put this down to the Esc on the inside track applying an electrical brake same as some rc car and boat ESC have. In fact until I swapped over to impact gearboxes my Panther and Jagdpanther would have a tendency to lock the inside track in all but the shallowest turns.

[tomhugill]

It's just the way the Tamiya DMD works - it won't properly pivot turn by design so the gearboxes don't get stressed out. I believe that the more resistance offered the wider the turning circle will be as the inside track is run proportionally to the outside track, a bit like a diff.

As for the tracks breaking - what are you running it on? Have you checked that the wheels, sprocket and idler all align? The tracks should have some slop in them. They are the weakest component in the drive train so tension will harm them.

The tracks seem to break links while running over grass. The grass is short and I feel that the ground condition wouldn't really be to much for the KT

Are you using schumo gear downs? I've always found the stock plastic king tiger tracks very weak and not really fit for purpose.

[billpe]

This is very strange, my experience of Tamiya electronics is completely different, on my Tamiya king tiger and Panther etc the Tamiya dmd/MFU combo were one of the only electronics packages that stopped the inside track and allowed tight turns, I put this down to the Esc on the inside track applying an electrical brake same as some rc car and boat ESC have. In fact until I swapped over to impact gearboxes my Panther and Jagdpanther would have a tendency to lock the inside track in all but the shallowest turns.

I assumed from Awins description he was going forward and turning rather than skid turning with one track stopped.