Attempted repair of Delta 31-695 after blue smoke.

 

This model.  Purchased new years ago.

If I recall correctly it tripped the breaker.   I think/hope the blue smoke was from the capacitor.   The motor would still turn but not come up to speed. 

The multimeter did not charge the cap and the winding look like they just left the factory.  No I did not take the meter to them.

This is an induction motor without starter windings, switch or capacitor.   

Does have a run capacitor its actually a Mallory with the same number.

Cornell-Dubilier PSU27015A

Mfr. Part #: PSU27015A
Allied Stock #: 70186362

Description

Capacitor, 270 to 324 uF, 110/125 VAC, 50 to 60 Hz, -40 C, +65 C, 10% (Max.)

Need to grab the cap and check but this is the one I found in my search history.  From Delta its $30.  The electronics parts houses charger $17 and up.

The motor is housed inside the sander body and was difficult to remove.   The motor mount pivots on a rod which is driven into holes allowing it to span the body.  One end of the rod has splines which dig into the hole to prevent it from turning.  It should be driven out from the non spline side.  Two C/Cir clips trap the motor mount in the correct position.  The are deep within and I have no idea how I am going to get them back in.

While I had it open I changed the motor bearings.  Uses 6302 ZE replaced them with 6203 RS's which I had on hand.  Used the bearing splitter to remove both bearings.  Used to brake press's 3rd cylinder to press the back cover off the rear bearing as the finish from the factory was dismal.  Did not take much.  Polished the armature bearing journals in the lathe with 600 then 800 grit wet/dry dry.  After the polish they were easy to install but still a tight fit.  The sort where you wiggle the bearing to get it to move up to a point.  Then it slides on.  One end needed a little persuasion with a pipe on the inner race but not much.  Reassembled the motor with little difficulty.

Still need to check the bearings on the roller that carry the sanding belt.  If they are good it is time to start putting it back together.

Sunday May 9 

Installed the motor.  For future reference I did not drive the rod in quite to where it is centered.  Its close but not quite.  If I have to drive it out again it needs to be driven from the side where the rod is below the surface of the case.  Putting the cir clips on was not hard using the huge needle nose pliers.  First was easy.  Positioned the 2nd one in the groove with the pliers and finished pushing it on with a T handle allen wrench.

Pulled the bearings on the driven end of the belt.  They are dry and tired.  In the left image I was attempting to pull the holder off the bearing but the bearing came off with it.  Used the arbor press to remove the bearing from the holder. On the right I got the bearing splitter behind the 17mm snap ring which positions the bearing and ruined it.  Should be able to get that locally. These bearings are the same as in the motor 6203 RS.  Will order 10 of them this time.   Have yet to remove the bearings on the other end of the belt.  Initial research indicates they are not so common.  Might have to get them in Dalhart TX at the bearing shop.

Hope the motor works when I get a new cap for it.   Will be a few weeks as I want to gather all the ELS stuff first so I can make one order to Mourser or Digikey.  Its about $15 cheaper.  

Update:

New cap did not help.  Runs the same with or without it.  Need to investigate further.  Looking grim.