Chosen Solution

My Dexter orbital sander runs and the electric motor spins but for some reason when applying pressure on the pad, the pad hardly spins. Eventually with enough pressure the pad will stop altogether while the motor still runs. This is unrelated to the hook and loop pad not holding the sanding paper disk. Any idea how to fix it? PC350RS 125 mm

Update (06/12/2022) Hi, the backing plate does have a visible circular line of chafe however it is not grooved or anything.

. There is a center screw on the shaft I believe but I could not find a way to open it as it only can spin with the part beneath it. The device has no lock button. I belive this maybe a slipping belt issue, either a gone one or covered in dust. However I cannot find a way to get to it, or find a replacement from this seemingly non existant Dexter brand

@yoya sorry had to post this as an answer even so it is not. Needed to do this to add a picture.

The way it looks is that there is a bearing that the flange with the threaded holes is pressed on the outer race. The inner race of the bearing is mounted eccentric on the motor shaft. That means that the way it is right now, only the inner race would spin with any kind of torque. The outer race (and thus the part where the sanding disk mounts to), could actually be held stationary since it is a ball bearing. We are missing a connection to the out race (sanding disk) there should be some sort of clutch belt that engages this. Also, I marked something that looks like its cracked etc. Just check on that for us. You may have to take the bearing of the shaft. Can you try to spin the outer part of the bearing. the part that holds the sanding disk? Put some screws in the opposite threaded holes and use a screw driver to see if you can turn it without turning the motor. If my theory is right you can, which you should not. That would mean that no torque transfers to the sanding disk. Let me know if this makes sense or if this is just a bunch of blah blah blah If it sounds like this I will clarify what I mean