Troubleshooting a lathe noise - Jet 1642

[Steve Paxman]

My lathe is only about 3 or 4 weeks old. It's a Jet 1642, 1.5hp version. When I turn it on, it makes a distinct grinding or clicking sound from within the headstock, once per revolution. I've read about a lot of people having this problem, but all the issues they identified don't seem to be my problem.

Here's what I have done: Opened up the little door where you move the belt, and I inspected where the magnetic tachometer sensor is, and verified that there is nothing rubbing there. Then I looked where the spindle lock button goes into the spindle, nothing is rubbing there. I checked the set screws on all the pulleys, on both the pulley on the motor and the two pulleys on the drive spindle itself. All set screws were nice and tight. Then, just for fun, I took the belt off of the motor pulley altogether, and spun that one by hand, no noise at all from the motor shaft or pulley. Then, with the belt still off (just dangling from the spindle pulleys), I manually rotated the lathe spindle. I heard no noise there either - very smooth.

All this kinda makes me think the sound is coming from the belt rubbing against the side of the pulley in some section as it rotates around, or something like that. I don't really see any anomalies on the belt as I inspect it - nothing sticking out the side that might rub or anything like that. Good news is, I think, if it's just a belt rubbing on the pulley, it's probably not a big deal, just kinda annoying.

Anything else I should check?

[Dwight Rutherford]

Have you called Jet ?

[Russell Eaton]

If I remember right on that lathe you need to undo the cover at the readout for the rpm's. Make sure the lathe is unplugged and then you can tighten the other set screw. It will be on the left side of the upper shaft, not the motor. That usually solves the problem. It can work loose from time to time.

[Tom Sherman]

Steve you might check the ways on the pulleys to make sure there are no pinch marks there.

[Larry Matchett]

I have a friend who had the same problem. I checked everything on his lathe. All was well. I even tightened all of the set screws. Still made the clicking sound. Then I noticed he had a nova chuck on the lathe. Took the chuck off no more clicking sound. The nova II chuck has a loose insert where you tighten the chuck. Might not be your problem but is worth checking.

If that is not your problem then here are some other things to check.

1. Run your finger on the inside of the belt. Make sure there are no knobs etc on the ribs.
2. Take a brass brush and clean the grooves in the pulleys.

None of the above call JET.

Good Luck

[Richard Jones]

Steve,

Is it possible that the collar that accepts the spindle lock pin (part #74) is rubbing against the headstock? Mine has done this a couple of times.

[neil mackay]

With bearings, be they roller or ball as you have in your head stock. They will grind and or click when damaged or worn out.

How does that happen on a new lathe? The most common cause is occurs during installation of the bearings, and the most common cause is damage to the seals covering the bearing cage or if no seals damage to the bearing cage its self. Either of these two will ruin the bearings with hours of usage.
If you can try and see any dents, hammer marks, or punch marks on the seal or cage. Failing that get a long screw driver and with the lathe turned off rotate the headstock shaft with the blade of the screw diver firmly placed on the outside of headstock near to the where the sounds is coming from and rotate the shaft by hand, oh place the handle end of the screw driver up to your ear, you will hear very clearly the grinding and or clicking, check all the headstock bearings to locate which one is the cause.

[Noah Barfield]

I had this issue when I first got my Jet 1642. After checking everything above, I realized I simply had a loose belt. Have you checked the belt tension?

Noah

[Phil Rose]

I experienced a similar problem with mine a couple years ago. Final solution was in the handwheel. Once removed the sound went away. Reinstalled and all is fine now.

[Ken Fitzgerald]

Since it's 3 or 4 weeks old, contact Jet. Let them walk you through the troubleshooting procedure since it's still under warranty.

[Richard Jones]

Steve,

any resolution to this?

[Steve Paxman]

Not yet. I'm still 90% certain that it's just the belt rubbing somewhere, since with the belt removed, the bearings make no noise at all, and nothing else seems to be rubbing. But it has been several days since I have been about to get out to the garage.

[Chuck Jones]

Steve,

Is it possible that the collar that accepts the spindle lock pin (part #74) is rubbing against the headstock? Mine has done this a couple of times.

That was certainly my clicking source a few years ago. I have also noticed the clicking from the SuperNova II chucks.

[Steve Paxman]

Just thought I'd update everyone here. After looking over the whole headstock and trying my hardest to isolate the problem, I finally resolved that it was a simple matter of belt tensioning. I was making the belt too tight. Now, when I move the belt from low to high speed or back again, instead of just dropping the motor and letting it come out where it may, I make sure there is about 1/4" deflection in the belt. At that point, the sound completely disappears, and it runs smoothly and quietly. I'll certainly still be paying close attention to see if sounds develop again, but for now, unless I suddenly start getting the belt to slip a bunch, I'm calling this problem resolved.

So there you go.

[Dick Strauss]

Steve,
Did you check your pulley alignment? Your belt may be trying to walk off the pulley and then jumping back. Place a short straight edge across the ends of the pulleys. I think the straight edge should ride across the ends of both pulleys at once.

Your belt may have an internal defect as well.

When you give the belt less tension, it causes a less dramatic jump of the belt in either of the above scenarios.

I hope something here helps for the future.

[Stan Smith]

Steve,
Did you check your pulley alignment? Your belt may be trying to walk off the pulley and then jumping back. Place a short straight edge across the ends of the pulleys. I think the straight edge should ride across the ends of both pulleys at once.

Your belt may have an internal defect as well.

When you give the belt less tension, it causes a less dramatic jump of the belt in either of the above scenarios.

I hope something here helps for the future.

Thanks. I have a slight noise in my pulleys so I appreciate your suggestion which I will do today. I also have a noise in my motor (1221vs lathee). Jet support says it could be a fan blade rubbing on the shroud. I looked at the parts page for the motor in the manual and I don't see any fan or shroud though. The noise is intermittent and not constant and it was there the first time I turned the lathe on.