The drum on my bosch wfmc1001uc won't spin but it does drain.

Draining has nothing to do with spinning.

open the back of your machine and you can see the mechanical parts of your washing machine

try to turn it ON , just keep a distance enough for you to see,

1. check the belt if it is attached and aligned (if loose, tighten it a little bit)
2. check if the motor is running ( if not, check the capacitor-small aluminum tube with wires) if busted replace it.

3. check if there is any hamming sound from the motor, if make a humming sound but does'nt rotate, take it out and bring it to machine shop to replace the bearing or bushing