HP 9825a

[cruff]

I thought the outer diameter of the roller should be larger than that. I have used the procedure talked about in these Museum and Vintage Computing Forum discussions to rebuild rollers.

Clamp the motor securely, power it with somewhere between 5 to 12 VDC, a variable power supply works nicely. I found about 10 V provided enough torque to not stall. Use a new Xacto knife to trim the "magic tape" to somewhat wider than the width of the hub so that it will stay on the hub during use, but is not too wide to rub on the cartridge housing. If you don't do this, the repaired roller will eventually be spun off the metal roller during use. Use 80 or 100 grit sandpaper or a diamond nail file to reduce the diameter to between 10.7 - 10.9 mm (0.425" nominal) and to clean up the edges you trimmed with the knife.