Is you process something like the following:
1. Remove shaft from housing,
2. Press off drive gear,
3. Replace shaft with one of desired diameter,
4. Add a bush to support original drive gear,
5. Stick it all back together?
Motor is OK
Bevel Gears - https://www.ebay.com.au/itm/183938849218
Deltang RX - I only use 1 per for servo and 1 for brake lights.
Lipo - 180mAh, selection mainly driven by physical size
Servo - I cut plugs off and solder directly.
Switch - SPST https://www.ebay.com.au/itm/264561276899
Not vehicles but shows how I made working uncouplers using Plantraco Actuators. The Deltang Rx6x had no F pads so I have added FETs to P pads to obtain sufficient current for the coil.
Giles,
I am converting two Canadian Military Pattern "Blitz" Trucks. One in 4mm and one in 7mm. How do you glue the stub axle into the bearing?
Rod Hutchinson.
These are examples of my foray into radio control. HOn30 was explored first because of the trouble I had with poor electrical contact between rails and wheels.
I moved to 7mm because my eyeballs don't work as well as they used to.
HOn30
O16.5 on wooden rails
O16.5 radio control couplings and lights (and motor also)