Short-stop blade brake original radial arm saw

[David Scheckman]

I’m hoping someone may have some experience with the blade brake on a 12”, type 1, original saw radial arm saw. This is a stand alone DC injection blade brake. It’s labeled TW Woods, Model REM 2-2. It’s worked well for a long time. However now the saw will not turn off. Not just no braking, it does not turn off without throwing the breaker. I replaced the switch, which is a simple two pole toggle switch and that had no effect. It turns out the switch only controls the on/off signal to the blade brake unit, which then controls the motor. In the short term I’ve bypassed the blade brake operation so I can use the saw by wiring the switch to directly control the power to the motor. I can’t find any info on the web and don’t have a wiring diagram. I would think the brake wiring would include a fuse of some sort but can’t see one on the circuit board. I’d love to be able to continue to have a blade brake operating. All help or advice is appreciated.
Thanks,
David

[Bill Dufour]

Is this a three phase motor?
Bill D.

[David Scheckman]

It’s single phase, 220 volts, 2hp motor.

[Ken Fitzgerald]

David, what brand is the saw?

[David Scheckman]

The saw is an Original Saw Company 12” type 1 model.
David

[Vince Shriver]

You might get do well contacting Original Saw for some input: (800) 733-4063 or (641) 843-3868.

[Darcy Warner]

https://www.ambitechbrakes.com/

I have had several that needed repairs and they are more than willing to help.

I believe most wiring diagrams are available on line.

[Darcy Warner]

David, what brand is the saw?

The brand of saw has nothing to do with the aftermarket/accessory short stop brake. Its function is to stop the blade quickly be means of injection braking.

[Ken Fitzgerald]

I wasn't aware it was an add on accessory. Sorry!

Electronic braking is something with which I am familiar. We used reverse current braking on the 2000+ lb. rotating frames on CT scanners.

[David Scheckman]

In case anyone is following and interested, I figured out the problem. From what I learned as I replaced the switch and then bypassed the brake, I reasoned there must be a relay in the motor brake box and that it had failed or was stuck. Opened it up again this morning and sure enough there’s a relay on the board. Tapped on it a few times, wired the switch back to its original position and sure enough all is back working fine. Satisfying. Will be easy to replace the relay if it gets stuck again.

[Ken Fitzgerald]

David, something to keep in mind. The contacts on relays will sometimes pit like the contacts on points in the old car ignition systems. Often you can burnish the contact on a relay. They used to make burning tools but I have used very fine emery cloth. With power removed! Just put it, tool or cloth between the contacts, close the contacts and work the tool or cloth back an forth gently.