Remove motor and cut contact

Remove the two clips (A) and take the original motor out. The cut the contact (B) at the edge.

Fold contacts 90 degrees

Solder wires to motor

Solder the wires NEXT to the contacts, not on the contacts, as the motor as to be as close to the front as possible, in order to have space for the flywheel in the back and to reach the gear in the front. There is a small Plus (+) on the motor next to one of the contacts. Fit a red cable here and keep this contact and wire on the right side of the train (seen in the direction of the front of the train). Solder a black cable to the left contact.

Slide worm on motor shaft and fix.

Slide the worm on the shaft on the motor side with the wires. Push until the end of the shaft aligns with the end of the worm.

Fit flywheel

The flywheel slides over the shaft (non-wire side). When you move the shaft, you will feel a bit of play back and forth. Make sure the flywheel almost touches the motor and it can run freely.

Test fit and glue motor

Place the holder with the motor part towards the front. It should be a tight fit with no movement back and forth. Then test fit the motor, making sure the blades of the worm have a little room to move.  The cradle for the motor is a very accurate print, so your worm should have the right distance from the gear. Check how it runs in forward and reverse, when holding the motor in place with your fingers. 

When you are sure it is working well, put a layer of epoxy glue (short drying time is advised, like 90 seconds) in the curved part where the motor will fit. The press the motor in place.

Glue motor assembly in place

The worm is correctly fitted, when you can rock the wheels a little back and forth with your fingers. When they don’t move at all, the worm would be too tight. But everything should have a perfect fit. Use superglue at the right places to fix the motor assembly in place. You know what the right place is, if you see where the gears in the train are. Avoid glue on those!

Solder wires

Cut wires to the needed length and solder them to the contacts or to the decoder if you run digital

Note for digital users: for this coreless motors, you might need to change some CV settings.

Assemble model

Test the model (note that without the housing, there is not much weight on it) and when it’s all working, grease the gear if needed, put the housing back on and enjoy the incredible change you have established. I hope you had some fun on the way.