My 5-year-old porter-cable random orbital sander has been acting up for past few months. (I’m an occasional hobbyist woodworker) It would slow down for a while and then slowly work its way up to speed again. Today after sanding out a 3×8 tabletop it seems to have finally died, slowing down and never revving up again.
Have I finally killed it? A friend said sometimes electric tools can have motor brushes replaced and restore their power. Does this sound like motor brushes and are they even replaceable in a $60 tool like this one?
thanks
gaf
Replies
Gat, Check the ballbearings.
They usually get fouled up with sawdust and dirt. If they are dirty, soak in paint thinner or lacquer thinner then re oil or grease.
If these bearings are the sealed type, cook them over low heat immersed in vaseline and it will suck up the grease. Don't over heat Stein.
Edited 10/25/2003 4:29:44 PM ET by steinmetz
OK: I give.
The ballbearings are part of the motor assembly?
Which means taking the plastic housing off? You ever done this? I've removed all the screws I could find and managed to get the lower housing off but the black part that surrounds the motor won't come off. Tried prying with screwdriver and can force the top apart a bit, but something seems to be holding the bottom halves together still?
Assuming I get the housing off, where or how do find the bearings and remove them?
I had a similiar problem apprx. 10 months ago. Couldn't get motor housing apart. Not really a solution to problem but........for $60 - $80, pitched it and bought another. Unit mentioned lasted about 8 yrs before I 'smoked' it.
Best Regards,
NAW
Gaf,
The bottom of the sander is held together by the plastic skirt - the part between the main sander body and the spinning pad; it is also what the dust bag is attached to.
To remove it, you will first have to remove the entire dust bag assembly. It may be held on with screws, but most likely it is mounted to the unit using a tight fitting rubber gasket.
Start by removing the dust bag. Next you'll need to remove the dust nozzle (the part that the bag attaches to) - this is the part that is most likely on with a friction fit. It will be a very tight fit, but it will come off - a little twisting action while you pull should help.
Once the above mentioned parts are off, remove the two screws holding the skirt on and the sanders outer shell should come apart. Be aware that a number of components (e.g. switches) are being held in place by the two halves of the body being to screwed together. When you're ready to separate the two halves, lay the unit on its side and carefully lift off the top half.
I would recommend that before you start removing parts (i.e. bearings), that you give the exposed unit a thorough cleaning using compressed air and maybe some cotton swabs or a clean rag. Blast out all of the dust, especially around the armature assembly. It is also possible that the carbon brushes on the unit have worn out, and if so must be replaced.
With everything cleaned, reassemble the entire unit, and test it out.
If you have any questions, please feel free to ask!
Dan Kornfeld, Owner/President - Odyssey Wood Design, Inc.
Edited 10/26/2003 2:25:10 PM ET by Jackie Chan
Gaf, Jackie Chan knows much more than I about the particular model
I think I have one here. Porter Ca ble Mod.333 5" random orbit sander.
But mine has just a cannister type dust collecter (not a bag) The type I refered to was a PC 1/4 sheet dome type sander.
To check if the tool is suffering electrically, use a resistence checker across the two blades on the plug.
(With the tool un plugged,of course) When you turn on the switch, you should get a reading that there's continuity.
If no reading, maybe brushes, maybe switch. Stein.
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