the belt keeps coming of my beco wma 10w?

the drum drive wheel is held on by a single allen bolt some times if the machine is over loaded the belt triying to turn the weight can undo the bolt allowing the drive wheel to flex and the belt takes the easy route and slipps off
it worked perfectly after i did this as usual it was the simplest thing good luck if this helps anyone else J

JimnSara
October 2011