Sears Model 100 RAS

[Mike Phillips]

I have a Sears Model 100 Radial Arm Saw. As I understand it, the motor is supposed to tilt. This one has been in storage for many years. Even when pushing the release under the handle in this picture, I cannot get the motor to tilt. Is something frozen from lack of use?

The motor has a problem in that it's slow starting, and it runs sporadically. The general advice is to take the motor apart and clean out the sawdust. Does this motor have brushes? Does it have a starting or run capacitor? I can't get into it until I can tilt it.

Thanks.

314676

[John K Jordan]

I have one similar but not the identical model. On mine I loosen the knob below the handle then hold the spring-loaded release button (behind the handle) up with my forefinger then tilt the motor. If that doesn't work on yours then something must be stuck.

I haven't used mine in 10 years so I might give it to the first person who comes to visit or trade it for a good hammer.

JKJ

[Jesse Busenitz]

My dad has one of these saws and it seem like you had to hold the release lever and then rock the head back and forth before it would release..... probably just need to clean something out.

[Mike Phillips]

I've beaten it with a rubber mallet and sprayed it with Kroll Oil, and I cannot get it to tilt. There has to be a catch that is not releasing. It looks like I may be able to disassemble part of the mount that will let me remove the motor. Maybe I need to find a manual first.

[Doug Ladendorf]

Mike, I think John is right that you also need to loosen the knob under the handle. You might even remove it to be sure nothing is impeding. A manual should be available online as a PDF.

Doug

[Allan Speers]

The motor has a problem in that it's slow starting, and it runs sporadically. The general advice is to take the motor apart and clean out the sawdust. Does this motor have brushes? Does it have a starting or run capacitor? I can't get into it until I can tilt it.


Evidently there were two types of motor used on these. Everyone says they were induction, and most probably were, but mine (not a model 100) has brushes. I'm rather confused about this myself.
Check your parts diagram to see if there are brushes & a brush holder. note: some universal motors also use a capacitor, just not a "start" cap.


Regardless, all electrolytic caps go bad over time, and they fail a lot sooner if you DON'T use them, so plan on replacing them no matter what.

[Joe Kaufman]

Turn the knob under the handle to unlock the motor tilt mechanism. Lift the thumb screw and plunger assembly behind the handle (in your picture) to disengage the index pin. My saw has been in the same position for 20 years or so and when I tried it, I needed to use a drift punch and hammer to free the index pin. Use a punch in the slot of the tilt bracket and the underside of the thumb screw. Be careful to not bend or break the screw. You might apply some penetrating oil in the slot before you begin. I remember when I used to use the saw that it required applying a rocking motion to the motor to help free the index pin.

Joe

[Joe Kaufman]

It is an induction motor and there is a start capacitor under the cover - no brushes. There is also an electro-mechanical brake assembly under the cover of the threaded shaft end of the motor - IIRC. You could just leave the brake plate assembly out of the motor to verify that it is not part of the problem.

[Mike Phillips]

Turn the knob under the handle to unlock the motor tilt mechanism. Lift the thumb screw and plunger assembly behind the handle (in your picture) to disengage the index pin. My saw has been in the same position for 20 years or so and when I tried it, I needed to use a drift punch and hammer to free the index pin. Use a punch in the slot of the tilt bracket and the underside of the thumb screw. Be careful to not bend or break the screw. You might apply some penetrating oil in the slot before you begin. I remember when I used to use the saw that it required applying a rocking motion to the motor to help free the index pin.

I suspect this one has the same problem - a stuck index pin. However, I don't understand your instructions for using the punch to free the pin. Could you try again? Based on the manual I found online, the column that holds the spring and index pin mechanism looks sealed on top. The screw moves easily, and the spring is working. The problem is the index pin is not released, as far as I can tell.

There is supposed to be a retaining ring to allow removal of the index components. I'll look again to see what I'm missing. Penetrating oil was applied a couple of days ago.

If this motor has a capacitor, I'll definitely replace it. It has never been replaced. My father bought the saw new.

[Joe Kaufman]

If you can lift the PN that is not the problem, I doubt that the pin is broken in half . Did you try removing the four capscrews and the handle? It would be advisable to put a block under the motor to support the motor before that. I don't think there is enough surface area at the back pivot point that you couldn't break free any corrosion by hand, must be the handle.

I Doug-out my manual..... There is no centrifugal switch, a relay is used for the starting winding p/n 30588 item #8 in my manual. Remove the back cover of the motor and as I remember the brake coil is energized releasing the brake anytime power is applied to the motor, you might watch for that. The brake disc could have a rusted surface also.