Small Thomas World converted several MINIS to run on N gauge track, with the engines themselves being motorised. Not quite what you're looking for, but I have yet to see any other attempts. Here's an example with Thomas, Annie and Clarabel:
They made two motorised variants of him: this one has the power bogie in Thomas, while the other has it in Annie (which could be helpful in cases where it can't fit in an engine). Once the bogie could be converted to battery power, an A23 (12V) battery would likely last longer than individual button cells.
If using the original wheels, the loose rear axle would have to be replaced with a rigid one (with a gear or pulley on it) and the wheels modded to fit traction tyres; or replaced with a custom wheelset with grooves for tyres.
They made two motorised variants of him: this one has the power bogie in Thomas, while the other has it in Annie (which could be helpful in cases where it can't fit in an engine). Once the bogie could be converted to battery power, an A23 (12V) battery would likely last longer than individual button cells.
If using the original wheels, the loose rear axle would have to be replaced with a rigid one (with a gear or pulley on it) and the wheels modded to fit traction tyres; or replaced with a custom wheelset with grooves for tyres.
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