Sigh- still fighting the powermatic 66 alignment

[Jonathan Freinkel]

Frustrating is about as accurate of a term as I can think.

Before I removed the top I was less than .007 off. After I removed it I found that the middle belt was not tight and so I ordered new belts and bought and installed new bearings.

After reassembly, I notice that the center belt is still not as tight as the others. I've tried to swap them around and it's the same outcome. If I run it for more than 30 seconds the belts get hot! I checked the pulley alignment and its good. Surely that's not normal? Could the arbor be bent? My HF dial indicator and magnetic basr is all over the place but I don't trust it as a quality tool to justify a new arbor

Lastly if I only put in 2 bolts I can get it close but the third is off enough that I would have to grind the hole larger. I would be OK with this except I know it was very close before.

All help is appreciated!!

[Myk Rian]

There is nothing wrong with those indicators. It's telling you something. Listen to it.

[Thomas Hotchkin]

After reassembly, I notice that the center belt is still not as tight as the others. I've tried to swap them around and it's the same outcome. If I run it for more than 30 seconds the belts lignment anget hot!
All help is appreciated!!

It is hard to get a set of v belts that match in size. Use to be that you got someone at your V belt suppler, check all the stock for three that matched. I have found that Goodyear's line of VX v belts to be great at match sizes, even with ones made in different country.

[Jonathan Freinkel]

I tried to measure them with a digital caliper and they are all subjectively the same. It's all from one batch but the fact that swapping their location and having them having a constant difference has me scratching my head :/

[Don Sundberg]

Pulley worn different in the center? I'm not sure I can come of with a reason it would wear the center one short of being used as a sole belt at one time in its life. See how deep one of the belts sits in each of the grooves.

[Steve Rozmiarek]

It is hard to get a set of v belts that match in size. Use to be that you got someone at your V belt suppler, check all the stock for three that matched. I have found that Goodyear's line of VX v belts to be great at match sizes, even with ones made in different country.

Yep, you really ought to buy a matched set. They come packaged together. Also, fractional horsepower belt, ie on your saw, shouldn't run tight. Think of the weight of a motor hanging off the back of a contractor saw tensioning properly. Try way less tension.

[Jerry Bruette]

I don't think your arbor is bent, if it was the inner or outer belt would be the one with the slack. Pulley alignment shouldn't affect the middle belt tension either. As other posters have indicated you probably have one belt that is longer than the others, and it's probably not too much to worry about.

As to your indicator, I also have a HF dial indicator and have no problem trusting what it's telling me. As long as you're using it right and it hasn't been damaged it should be telling you what you need to know about your alignment.

If you go to a belt manufacturers web sight, like Gates, they will have information on how to properly tension your belts. It has alot to do with the series of belt and the center distance between your pulleys.

[Jonathan Freinkel]

Well.. Looks like the problem was the pulley!
I put it on a lathe and noticed that the groove was deeper in 1 section than another.

I managed to get them all to match now. .


What I am kicking myself about is I put it all back together and even squared it up! Then I went to lift the blade and it was about 1/4" over.
I pulled the top, Moved everything over and then reassembled and re-squared.

After putting the rails back on I noticed the splitter adjustment nut is off by about 1/8". Now I am trying to decide if I should grind it down or pull the entire thing apart again :/

I really appreciate everyone's help! I wouldnt have thought of some of these things on my own!