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Dewalt belt sander DW433 does not spin. HELP! Answered

I just bought a used dewalt dw433 and it arrived DOA.  It is the one with the sanding frame and don't want to have to send it back because I got it for a great price (now I know why). 

The motor runs (that is to say the armature spins), but the belt and the drive pulley does not.   The motor gets electricity so the brushes and armature should be fine. But could this be a drive belt or a "field" problem? I am very mechanically inclined but have never dealt with this type of diagnosis/repair.  I am sure I could fix it myself if I just found out what needs replacing. Please help!


YOu say "The motor runs (that is to say the armature spins)". Do you mean it runs when you pull the switch? OR the armature turns when you spin it? If the motor runs when you pull the trigger then it isn't an electrical problem.

There is probably a toothed belt that has broken or slipped off the pulleys. That should be easy to fix.

Here is a parts diagram and list. You need part 49.

P.S. You need part 49 unless one of the pulleys is broken or unlocked on the shaft.


7 years ago

My guess is that the internal belt, the one that turns the drive pulley, has broken. I've never disassembled that particular model belt sander but mostly, they all have similar internal design.
There are a lot of parts and if you aren't careful, it could be difficult to re-assemble. I recommend you locate a schematic to use for reference and that you lay the parts out in the order you remove them so you need only reverse the process. If you have a digital camera, take some pictures as you go so you can see how the parts fit together later.

It's kinda ironic. A belt sander doesn't work because of a broken belt.

I replaced on a Craftsman sander once. IT went on very easy some of the older designs are a real bear to work on.