While you wait for answers, we may have found some information which could help you.
Click here for Replace Side ScrewsWhere can I get a drive belt for a FERM belt sander FBS-1000?
Repair to Craft EP600 Sander?
FERM belt slipping?
PES 600 Parkside Orbital Sander?
Looking for parts?
How to release tensioner and change drive belt on sander Pa?