Unisaw Pulleys & Motor

[Ron Hampe]

There is also a possibility that something got bent when I upset this saw moving it from the basement to the new shop. Fortunately I had taken the table off and it went down relatively easy but landed on the tilt handwheel breaking the casting. Nothing appears bent and both the raise/lower and tilt handwheels spin smoothly and freely. I plan to check both with my dial indicator as soon as I figure out which box its packed in.

I have not found any cracks in the castings, nor have I attempted to run it, but there are 2 things that concern me. One is that the 3hp motor seems tighter that it should be, spinning freely for only a few revolutions by hand. The other is that the belts have either stretched or that the pulleys are worn or that I have missed something that is either bent or cracked. I ordered new belts, but before installing them want to check the pulleys for wear. Circumference is easy, but do I need to check the sides of the pulley grooves for wear and if so, how? Also how tight should the new belts be?

I bought this grand edition saw and several other tools from an older gentleman 5 years ago and I believe he had them for app. 10 years.

Thanks

[Tom Bender]

Pulley grooves rarely wear much, especially on a hobby shop saw. They typically run for decades on fans 24/7 so you should not worry about it.

Unfortunately table saws are made with the smallest pulleys that can survive so tension needs to be higher than would be needed for bigger pulleys.

Cast iron pulleys are much better than aluminum.

Toothed V belts are better than solid ones for small pulleys.

[Matt Day]

I assume this is all part of your thread from December where the saw fell over.

Pulley do wear, and you’ll see the flat spots in between the belts of the pulley gets smaller and become sharp.

Did you take apart the motor like you mentioned doing in the other thread?

Belts get “set” in them from lack of use. Doubt that would happen in a few months though.

Belts should be tight enough that the motor pulley doesn’t slip on startup, Other than that adjust the tightness to where the vibration is the least.

[Ken Combs]

I can't feel your motor from here, but can tell you that really free and easy coasting bearings are likely worn. They should have a little resistance to turning as the tolerances are tight, and when in good condition are filled with grease that will drag a little, especially when cool/cold.

If you feel no roughness or 'catching' when turning it probably fine.

[Frank Pratt]

And the friction from the start switch can cause a fair bit of drag & noise when turning it by hand. There's a big difference in the feel of spinning a 3 phase & single phase motor.