Jerry Lawrence
03-11-2017, 9:00 PM
Hi all,
The other day I was ripping some 4 foot X 2" stock of purple heart into strips of varying size, from 1/4 inch down to 1/16 ish, with my Powermatic 66. I noticed that the first 2" or so of the cut was very rough. The blade left chatter marks, for lack of a better way to describe it, like a quarter-circle of snipe basically. I know I'm not describing this very well, but hopefully you get the idea. Anyway, the marks were most prominent in the part of the strip between the fence and the blade...and only on the first couple inches, after that they were perfectly smooth. I tried adjusting the fence, changing blades, checking for square and run-out...but nothing helped. After I had cut awhile, I noticed that the table itself was getting warm, as well as the arbor nut, and assumedly the arbor as well. So I'm figuring the arbor bearings are fried. The saw is at least 25 years old, I have owned it for about 10, and as far as I know still has the original bearings. So...my questions are: 1. would bad bearings cause this "snipe" problem? Like maybe the bearings caused the blade to vibrate, leaving the chatter marks at first, but then once the blade got farther into the wood, it stabalized because of the support the wood provided? And 2. How tough of a job is it to replace said bearings? I found a pair online for $46 delivered, but also a complete bearing/arbor/nut and collar assembly for about $140. Would the complete assembly be the way to go? I'm not above doing a little work to save some money, but I've also attempted plenty jobs where I would have gladly paid an extra $100 to have avoided some very frustrating situations. Anyway, sorry for rambling, and thanks in advance for any and all advice!
The other day I was ripping some 4 foot X 2" stock of purple heart into strips of varying size, from 1/4 inch down to 1/16 ish, with my Powermatic 66. I noticed that the first 2" or so of the cut was very rough. The blade left chatter marks, for lack of a better way to describe it, like a quarter-circle of snipe basically. I know I'm not describing this very well, but hopefully you get the idea. Anyway, the marks were most prominent in the part of the strip between the fence and the blade...and only on the first couple inches, after that they were perfectly smooth. I tried adjusting the fence, changing blades, checking for square and run-out...but nothing helped. After I had cut awhile, I noticed that the table itself was getting warm, as well as the arbor nut, and assumedly the arbor as well. So I'm figuring the arbor bearings are fried. The saw is at least 25 years old, I have owned it for about 10, and as far as I know still has the original bearings. So...my questions are: 1. would bad bearings cause this "snipe" problem? Like maybe the bearings caused the blade to vibrate, leaving the chatter marks at first, but then once the blade got farther into the wood, it stabalized because of the support the wood provided? And 2. How tough of a job is it to replace said bearings? I found a pair online for $46 delivered, but also a complete bearing/arbor/nut and collar assembly for about $140. Would the complete assembly be the way to go? I'm not above doing a little work to save some money, but I've also attempted plenty jobs where I would have gladly paid an extra $100 to have avoided some very frustrating situations. Anyway, sorry for rambling, and thanks in advance for any and all advice!