The another motor, more like the normal flat can type, I have
still to investigate.
There were three motors in the CD drive which I dismantled. Two of them were
marked
"MDN3BT3CSAS".
A data sheet of this family of motors by Panasonic is at
http://202.157.137.134/pia/pdf/powermotor/MDN3.pdf
It was quite easy to put it in. The hardest bit was fitting the original
Hornby gear onto the output shaft of the new motor.
The new shaft is 2mm diameter and the Hornby one is a bit bigger. I filled
the hole in the gear with solder, drilled it out to just under 2mm, put in a
small taper with a round file, and forced it onto the shaft in the vice.
Seems OK !
The hole in the back of the old motor casing needed
drilling out to allow the gear on the motor shaft to go through.
As luck would have it, two of the tapped holes in the back of the new motor
lined up with slots in the old casing, so the motor could be fixed using the
screws which had held it in the CD rom drive. The head of one of these can be
seen in the second picture.
Here are a couple of pictures of the motor installed in place
of the ringfield motor in a Hornby 125 motor bogie.
The motor runs without getting hot, and stalled with twelve volts across it
only draws about 400mA.
The motor runs more smoothly than the ringfield and can drive a four car train
easily. With five cars it gets wheelspin. This could probably be sorted by
adding more weight.