Bad bearings or ?

[dalemcginnis]

For the past month my turnings have not been coming out right, tonight I discovered why. I put my collet on getting ready to turn and for some reason I turned the lathe on with just the collet and saw a huge wobble. Took the collet off and turned the lathe on and the spindle was still wobbling by itself. Took the head apart cleaned the spindle and bushings and put it back together and still wobbles. If I take my tool rest and place it underneath the spindle where it comes out of the bearing so it barely touches and turn by hand the spindle moves to almost a .2mm gap. My lathe is not making any strange noises but anything I put on the spindle wobbles. Doesn't matter if it's in the morse taper or threaded on.
So is that a sign of bad bearings or have I some how bent the spindle? It's a Jet 1014I lathe.

 

[pssherman]

I'd say bad or loose bearings. Is there any play in the axial direction? If there is, try tightening up the bearings. Usually you do this from the pulley side of the spindle. If you feel a 'gritty' motion when turning the spindle by hand, repalce the bearings.

 

[stevers]

Wow, bummer Dale. Check the bearings like he said above. They shouldn't move side to side. Or I should say, the spindle shouldn't move.

 

[leehljp]

I will not say that my suggestion is the problem but I will mention something else. I have a Rikon and while it is a good lathe, the head stock seems to have been manufactured to stricter tolerances for the MT2 fitting rather than the 1" threads.

I purchased a Beall chuck & collet set a year ago to fine tune my turnings only to find that it had more wobble than my standard mandrels. I also started using a newly purchased Grizzly chuck and found that it had quite a bit of runout. After realizing that the MT2 part was dead on, I discovered that the Beall and Grizzly were not seating against the backplate of the head perfectly. I took a carbide chisel and surfaced the backplate of the head. After that, I had decent runout on the Beall and Grizzly, not perfect but acceptable at .004 at the chuck. Good seating is a necessity. (After purchasing all of that, I moved to mandrel-less).

 

[Randy_]

Dale: Since you have the 1014I, it is relatively new and still under warranty. The first thing I would do is get on the phone to JET and talk to one of their technicians.

To be honest, I am not quite getting the exact nature of the problem. Here are a couple of questions for you.

1. Are you talking about a Beall collet chuck or a collet holder that fits in the Morse taper?

2. When you say you disassembled the headstock and cleaned the "bushings" what are you talking about. I don't think there are any bushings in the HS.

3. If you grab the spindle nose and shake it radially or axially, is there any looseness or play? Should be no detectable movement.

4. You say this started a month ago......does that mean the lathe lathe was working properly for some period of time before that?

5. How long have you had the lathe?


As to your last question, it might bad bearings or it could be a bad spindle; but I doubt very much if you bent it. Short of dropping the lathe on a concrete floor or taking a sledge hammer to it, you aren't going to be able to bend the spindle.

 

[randyrls]

Originally posted by leehljp

After realizing that the MT2 part was dead on, I discovered that the Beall and Grizzly were not seating against the backplate of the head perfectly.

Some people don't realize that a chuck must seat against the Registration plate at the back of the spindle nose. The threads only keep the chuck in place. Most metal working chucks do not come with a back plate. The back plate is mounted and turned to fit the chuck and register it exactly for the lathe.

My lathe has an MT3 taper and I use an MT3 to MT2 sleeve with pen mandrels. Once I put a chuck on and got terrible run-out. You guessed it... I forgot to remove the sleeve... [B)]

 

[dalemcginnis]

Thanks all for your help, I called Jet today and they think it's bad bearings and are sending me a new set. Just for the record here are the answers to your questions.

Originally posted by Randy_

Dale: Since you have the 1014I, it is relatively new and still under warranty. The first thing I would do is get on the phone to JET and talk to one of their technicians.

To be honest, I am not quite getting the exact nature of the problem. Here are a couple of questions for you.

1. Are you talking about a Beall collet chuck or a collet holder that fits in the Morse taper?
I was using the PSI collet which I had used before with no wobble, also if I put the spur center that came with the lathe in the morse taper it made a circle around the point of the live center. So the problem exists whether I use the taper or the threads.

2. When you say you disassembled the headstock and cleaned the "bushings" what are you talking about. I don't think there are any bushings in the HS.
Sorry, I meant bearings. I removed the spindle and bearings and cleaned everything and reassembled making sure all fit properly.

3. If you grab the spindle nose and shake it radially or axially, is there any looseness or play? Should be no detectable movement.

No movement. Also no noise when the lathe is running, but I can also see the handle on the back of the spindle wobbling.

4. You say this started a month ago......does that mean the lathe lathe was working properly for some period of time before that?
Yes the lathe was working great. When I first started I thought I had a bent mandrel and replaced it but didn't help. Then yesterday when I put the PSI collet on it looked like I had it on at an angle, but it was flush. That's when I took a good look at the spindle by itself and saw a problem.

5. How long have you had the lathe?

Just over a year. Jet is replacing the bearings.

As to your last question, it might bad bearings or it could be a bad spindle; but I doubt very much if you bent it. Short of dropping the lathe on a concrete floor or taking a sledge hammer to it, you aren't going to be able to bend the spindle.

 

[Randy_]

Dale: I hope the new bearings will resolve your problem for you. It sure is a puzzle that the bearings are bad and there is no noise or spindle play; but I guess anything is possible?? Be sure to follow up and let us know if the new bearings fix your problem.

Probably doesn't apply in this case; but I recall seeing a post or two in the past where there was a wobble in the handwheel and it was due to a loose set screw.

 

[dalemcginnis]

OK, got my new bearings today. Put them on and still has a wobble. If I put the stock center I get just over a 1mm diameter circle. I also have the wobble if I mount anything on the spindle.

Any last ideas before I pack it up and take it to a service center and let them try to figure out whats wrong?

 

[Randy_]

Given everything you have posted, it sounds like the spindle is bad; but spindles are not the type of thing that go bad. Either they are or they aren't. I don't know about others; but I'm out of ideas. The service center sounds like a good idea!!

 

[dalemcginnis]

Well, I took it in today. Bent spindle![}] Don't know how I bent it, but he said it's not the first one he's seen. Anyway he has to order it, so I'm out of commission till it comes in.

And here I've got a bunch of new blanks I poured and am anxious to see what they look like. Oh well, they say "patience is a virtue", I guess I'm going to have to learn a little patience.