Looking at it more closely Brian, I have a couple of questions on the chassis.

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It looks like the motor is fixed through the plate carrying the output shaft on the gearbox – have I got that right?

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It also looks like the wheels are held by outside frames and if so are they removable?? Having had an internal drive belt fail on me due to my own incompetence I am a bit nervous of not having a way to replace them without a major rebuild!

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It looks very elegant and a good solution.? I have a couple of similar chassis from Locos n Stuff but they suffer from being a bit jerky.? I think it is down to the gearbox which is (I believe) really intended for camera lens focusing.

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Cheers, Robin

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