Now that magnet polarity is solved, I gave the lathe a test run to see if noise and vibration that were present with the old spindle/bearings was still there. It is. Very loud motor whine starts at about 1250 - 1400 rpm coupled with way too much vibration. Makes the goose-neck led lamp I sat on the top shake quite a bit. Fades out again by 3200 rpm. The only things I found that might be associated with the vibration are the pulley spacer (out of round) and the belt (small bump - on the outboard side, not the contact side) Suggestions anyone?
Call Grizzly, I had the same problem-They sent me a new head stock.
I turn bowls predominantly, so i haven't even had the belt on the higher speed range pulleys yet. Maybe i oughta flip to the higher speed range and crank the speed up just to see if it vibrates.
We had our club meeting today and I spent some time with 3 other lathes for comparison. a jet with reeves drive a jet 1462 with vfd a powermatic 3520 All three including, the reeves drive unit, were smoother in operation, though all three did have SOME vibration. None made noises quite like mine, though all made some. I noticed that if left in the middle of the rpm range where I get vibration that it settles into a rhythmic thrumming. Again, this is with no load, not even a chuck or faceplate. I inserted a pen mandrel and chucked my drill to it, spun it up quite handily into the 1400 rpm range. Had the belt to the drive pulley off. Had the vibration. Eliminated the possibility of a defective belt
Hi Terry, I would seem like you may have isolated the vibration to the spindle and pulley. So, it may be useful to check the spindle for play. Grab the 1-1/4" end of the spindle and yank it in all directions to feel if there is any play or looseness. Next, I'd suggest checking the pulley on the spindle and check for axial or radial runout. You should be able to see this visually or perhaps putting a dial indicator on it. If that doesn't uncover anything, I suppose that there could be some strange issue with the bearings where the balls or the cage holding the balls is doing something funny. I am guessing that if there is something funny going on with the bearings (after ruling out looseness in step 1), that you might feel is when slowly rotating the spindle by hand. It should turn very smoothly. continued
Part 2 (continued) If that doesn't uncover anything then put a dial indicator on each end of the spindle and check for runout. It is hard to imagine that they turned the spindle in a non-concentric fashion (like a crankshaft) but I suppose that anything is possible. If that doesn't uncover anything, then I'd push for a new headstock.
The spindle assembly may be loose. If someone tightens the pulley set screws(2) before tightening the jam nut the entire assembly will be floating instead of lightly loaded. The spacer fits the spindle quite loosely. The preload from the jam nut is all that keeps it from spinning. With the jam nut on the other side of the pulley tightening the pulley set screws before the jam nut, either from the factory or after a tear down, lets the spacer spin. At first it is pretty quiet but after a little galling it still spins but sounds a lot like a bad bearing as it grabs and hops. The spacer has to be in there and the jam nut has to preload the entire assembly for the headstock to work as designed. This is an undocumented design change and doesn't match the exploded view in the manual on page 44 which shows two snap rings instead of one snap ring and a spacer. My current theories anyway! Hu
Hu gave you some good advice and leads to follow. One day I was turning and heard a knocking sound at some resonance points. It was with a medium sized somewhat unbalanced chunk of wood. After doing some troubleshooting I found the source of the problem and it was kind of embarrassing. The headstock was not locked down. It was at its leftmost position against the pin, but it was moving within the play of the ways. I'm guessing that you have your headstock locked down, but thought that I'd mention it anyway.
I had a couple of instances of rattling from the spindle, then I remembered - I forgot to take the push bar!! DOH.
Mark, Brice, None of the rest of us have ever done these things!(while looking up watching out for lightning!) That is why I like the bigger handle on my homemade knockout bar. Once was enough spinning a big out of balance chunk on my lathe too. Every time I leave my lathe I bump the lock down lever to check it when I come back. Just thinking, I wonder how much it would annoy me if I reversed it so it is at the front of my machine? I think I will at least look at that possibility. I had the classic happen years ago. A friend's wife called me very upset. She had locked her keys in the car. Called her husband at work to bring his keys. He had to get out of a secure area an hour away to come to her aid. As he was on the way in those pre-cellphone days, she noticed a back window open. Her husband would be furious to put it mildly. Obviously only one thing to do, "Quick, roll up the window and lock the door!" Neither of us ever told her husband about the open window. Hu
