Craftsman Miter saw Motor Problem

[oskar]

The motor shown in the attached pictures is from an old miter saw I had and after I broke the fence decided to scrap it but kept the motor. I want to use this motor in another jig but testing I found the blade rotation turns backwards and I can’t figure out why.

The red and grey wires coming out from the motor (the grey wire is about half the gauge smaller than the rest) and are going into a limit switch which was part of the trigger. From the limit switch the black wire along with the white from the motor is the power supply

I have no idea what is the purpose of the gray wire but I think it must be some kind of a safety feature which makes the blade going backwards. Also the little window shown in one of the pictures indicates there is a safety feature somewhere

Any ideas how to re wire it?

 

[JimDawson]

It looks like the blade rotation is correct for miter saw use. The grey wire might be for a soft start system. If that is a soft start, you will have to disable that to get the router control to work correctly.

In order to reverse the blade rotation you would have to change the wiring inside the motor to change the winding relationship to the brushes. But, reversing the blade rotation could cause the the blade securing nut to loosen in operation.

 

[oskar]

I solved the problem with the wrong rotation, my fault!

I used a 7-1/4” blade from a Skill saw (I thought all blades were the same) but when I compare it to a 10” miter saw blade the teeth on both blades are not the same, they point in the opposite direction. So installing the 10” blade now the rotation is good.

It’s interesting what you say Jim about the soft start but how to I disable it? Just remove the grey wire from the limit switch will do it?

 

[David S]

I am not sure how old this motor is, or who made it for Craftsman, but some did have a separate winding for the brake, which was used to slow the motor when the switch was released.

David

 

[oskar]

I bought the saw in late 2003 and I remember it had the brake because the blade will stop quite fast.

 

[JimDawson]

I am not sure how old this motor is, or who made it for Craftsman, but some did have a separate winding for the brake, which was used to slow the motor when the switch was released.

David

I found a wiring diagram for a similar saw, and it looks like that is a brake.

 

[oskar]

That looks good Jim, thanks

In my case I have the red wire where the yellow wire connects to the switch, my black wire is in the same position and my grey wire connects to where the brown wire is above.

Anybody has an idea what will happen if I remove the yellow wire (in my case will be the grey) from the switch?

 

[David S]

If you disconnect that wire then you will disable the brake. All else is fine.

David

 

[oskar]

Good to know David, thanks

Thinking about it, I think it is good to have the brake because now the motor works fine and it stops quite fast. The router speed control works well but below about 2000RPM has no effect. So I will leave the wiring as it is for now.

 

[markba633csi]

In the diagram above, the brown is the brake wire. It corresponds to your grey wire, from normally closed switch contact to motor. It puts a short across the motor to stop it quickly.
mark