Delta Milwaukee 12” disc sander

[tcweb]

I have an old Delta Milwaukee 12” disc sander. The motor is a massive 110v monster. I can’t read the tag, it’s too worn, but I see “EL” stamped on it, and I can make out “repulsion induction motor”.

See pics.

My question: it spins counter clockwise. It has a shaft I. Each end, so I could reverse the motor. I have only seen these 12” spin clockwise. Is it acceptable to have one spin counter clockwise? Owner preference?

Also, I think the bearings are a bit too loud. This unit has been sitting unused for 20 years (at least) before I acquired it.

Anyone have any idea what these old heavy motors used for bearings? No oil ports, so does that mean I may have to pull the motor apart and replace the bearings?

I took a short video so you can hear…

What should I do to clean up the motor? Should I take it apart and blow out the grime? Or just use it? Any maintenance tips?


View attachment IMG_3045.MOV

 

[cathead]

Nice motor! I have one with slip rings and bushings and an oil reservoir, almost unstoppable on a 12 inch wire brush.
I would disassemble it somewhat to get to the ball bearings and work in some grease and blow out the cobwebs and run
it a bit before investing in new bearings. After sitting for so long, the grease likely has dried up some.

 

[tcweb]

Looking at the pic I posted. I can see that this is a Delta motor. Could this be the original motor for this delta disc sander? I thought they were all 3 Phase motors…


Funny how the picture show more detail than I can see standing over the motor…

If only the rest of the data plate was visible…

 

[f350ca]

To your first question on rotation direction, I have the one I built reversible. Probably run it equal amounts in both directions. Depending on the work its more convenient to sand on the right or left side of the disk, especially if working into a corner.
Its been a while since I researched them but to reverse a repulsive induction you rotate the brush assembly. Some have the brushes fixed, like the one I tried to reverse. Interestingly I believe it came out of an OLD gas pump, not a place you'd want sparks from the brushes.
The lines on you brush assembly and what looks like one on the housing would lead me to believe yours is reversible.
Have a large one, guessing 4 -5 HP on a shaper, as yours no tags, but its reversible.
Been so long I can't remember whether they had bushings or bearings,
Somewhat rare motors, high starting torque and low inrush current.

Greg

 

[francist]

Depending on how your computer screen is you may or may not see all the printing. Here’s what I make out:

Delta
BALL - BEARING
1 HP
REPULSION INDUCTION
MOTOR

EL

 

[tcweb]

It's a solid motor. I managed to loosen the rear bell housing, but cannot pull it off - the bearings must be a press fit on the shaft, and I have nothing to pull on. I don't want to risk prying against the bell housing and breaking it. My goal is just to pull it apart, clean it up, and re-grease the bearings. If it runs reasonably quiet, I'll be good.

So...suggestions on pulling off the bell housing? use a puller? I'd have to rig something for it to grab on, as I only have about 1/16" clearance from the bell housing to the motor case.

Thanks in advance,

Tom

 

[cathead]

If a person uses a reasonable amount of care, one can usually pry with two screwdrivers using the same amount of
pressure on both screwdrivers. Sometimes a little persuasion with a lead hammer is helpful as well. There is significant
importance to equal prying and knowing how much pressure to apply as unequal pressures will cock the bearing causing
consternation as well as inability to get it apart. Take your time, applying some light oil to the shafts may be beneficial
as well.

 

[tcweb]

I used a dead blow hammer to get the housing to rotate. Some penetrant helped.

After tapping it back and forth, it separated.
But won’t come apart completely. I will try the two pry bar approach and see.

I’d love to see what a motor repair shop would do. Maybe a slide hammer Screwed in to the 3 holes that hold the shaft cover?

Tom

 

[tcweb]

Got the back housing off. Bearing was gunked up. Brushed off the crap, worked in some penetrant, and then some light oil and it now spins free.

Sounds much better…

View attachment IMG_3052.MOV

 

[tcweb]

One more question for anyone who may have this disc sander. The casting is not parallel to the disc. I could shim the motor to bring them into parallel i suppose, but…maybe this is normal?