repairing old Tomy Trackmaster Thomas trains

We have brought (mostly secondhand) Blue trackmaster track and trains. these are all about 10/15 years old. they have a battery, motor, and a clever clutch mechanism to try to make them kid proof.
The grandchildren (3 and 6) love them and we have built up quite a collection.
I have repaired a few of them, usually electrical problems that are an easy fix.
One weak point is the drive is thru a very small plastic gear thats an interference fit to the drive wheel shaft. This gear splits. tried gluing it together but it doesnt last very long.
Cant find any replacement gears the same size, I think its too small to 3D print and I havent managed to get the wheels off the shaft, without breaking them, to replace the gear.
Bit frustrating want to repair them but just cant see how to do it, i guess that true of lots of plastic toys..
Mike

If mechano or lego don't help then DAVALL STOCK GEARS, at hatfield may be worth a call, they do a vast range of gear wheels in many substances including plastics. Good luck Noel

Mike , Any of the following Hobbies products of interest ? 1) Gearwheel set @ £15.99 2) Axle Gearwheel set @ £17.99. 3) Multi Ratio Gearbox @ £7.99 .

Trevor.

Also , any of the MFA 951 motor and gearbox combinations available for Cornwall Model Boats @ £9 ?

Trevor.

Hi Mike, no idea exactly what diameter and no. of teeth we are talking about here, but an idea - make or have made brass or mild steel gears, split them into halves, clean the shaft, flux, and solder / sweat the gear together in place on the shaft. Use just the tiniest pieces of solder, just enough to wick some in, so it doesn't run into the teeth. If the gear to shaft bond is not good a drop of 609 loctite cylindrical retaining compound would likely bond it.

Depending on quantity scope of the project and your budget, it is very possible to have an injection mould insert set made to produce new gears in acetal resin, with 3 pin gates for hottest knit/weld lines in the plastic and thus minimal chance of splitting again.

Also , replacement r/c servo gears available from larger r/c model shops and also Ripmax .

Trevor.

+1 for servo gears - may even be cheaper to buy cheap servo’s than gear sets.

pgk

Hi Mike,

What about replacing the broken gear with an O ring and friction driving the next gear?

Regards,

Alan C.