Chris Fitzpatrick
08-29-2015, 6:12 AM
Hello all , Hoping to get some help insight into a problem I have. I have a PM66 that's 10 years old. A few months ago I was using a dado blade and heard a noise as if metal had made contact with metal, it only lasted a second. I checked around and could see nothing but the saw sounded a little louder after that. When I put my day to day blade back on I could see it was tight in the ZCI and my after market splitter was not lined up any more. After checking around i found the set screw on the blade arbor was not as tight as it could be, so I tightened up and readjusted the splitter. Recently I noticed the blade was rubbing against the ZCI again, the set screw seemed fine.By this point it must have moved a total close to 1/8". I called Powermatic and a tech told me that any time a blade moves laterally like that it indicates that my arbor bearings were probably going. So I pulled off the top and tried to get the arbor shaft off but the pulley is really tight on there. I removed the two set screws on the pulley, took of the belts, but it doesn't budge. I don't have a pully puller, is that the only way? I tapped it with a rubber hammer around the edges, tried wedging wood in there etc.
Anyway i called Powermatic back and got a different tech who told me that the kind of movement I described would not indicate bearings. He said that the screw that holds the pivot pin in place must be loose or not on the flat spot. So I took the screw out, seemed tight enough and i could see by shining a flash light in the hole that it was on the flat spot and had marked the pivot pin fairly clearly. By that i mean it didn't look like the pin had moved while the screw was touching. So maybe this is not the issue and the arbor is? But I did notice something that I would appreciate feedback on. I've uploaded a picture of the end of the pivot pin. It has two nuts on it and a washer. It is not tight to the casting, should it be? I loosened the outer nut and saw there was a little more left on the thread, but not enough to tighten it up. Another thing which caught my eye was when I lowered the blade all the way , the gap stayed even all the way until the very last turn when I could see the the whole casting get pulled tighter, but when i start to raise the blade it returns to the original position. Maybe it doesn't matter as the blade would be below the table when it would move?
So I'm at a cross road, any thoughts?
Appreciate it,
Chris
Anyway i called Powermatic back and got a different tech who told me that the kind of movement I described would not indicate bearings. He said that the screw that holds the pivot pin in place must be loose or not on the flat spot. So I took the screw out, seemed tight enough and i could see by shining a flash light in the hole that it was on the flat spot and had marked the pivot pin fairly clearly. By that i mean it didn't look like the pin had moved while the screw was touching. So maybe this is not the issue and the arbor is? But I did notice something that I would appreciate feedback on. I've uploaded a picture of the end of the pivot pin. It has two nuts on it and a washer. It is not tight to the casting, should it be? I loosened the outer nut and saw there was a little more left on the thread, but not enough to tighten it up. Another thing which caught my eye was when I lowered the blade all the way , the gap stayed even all the way until the very last turn when I could see the the whole casting get pulled tighter, but when i start to raise the blade it returns to the original position. Maybe it doesn't matter as the blade would be below the table when it would move?
So I'm at a cross road, any thoughts?
Appreciate it,
Chris