Grundig CD-1 with CDM drive...problem

[Skorpio]

I have found the problem....the rubberbelt from the motor to the transmission wheel is to large.....but how do I find the right size?

It is a Philips CDM drive....but version?

 

[kaulagalvis]

GRUNDIG CD1 CDM12.1/0 this version you can to buy a new.