Lathe problem. Anybody have this happen?

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mdburn_em

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My jet mini is gobbling. I'm pretty sure I could call a Tom turkey with it. :(
I sent an email to Jet but I thought maybe someone here might have had a similar problem and could shine some light on it for me.
The noise is coming from the head.
The belt is not frayed and appears to be tensioned properly.
The shaft that would be removed to change the belt moves slightly. I hate to show my ignorance but I guess I have to. It moves about 3 small marks on my dial caliper. thousandths?
The hand wheel is snugged up tight. Could it be too tight. If I spin it by hand, it goes around a couple times.
Oh, my lathe is not VS.
There is no noise when I spin it by hand and when there is noise, it's not a grinding sound. Sometimes its a continuous gobble and sometimes it's intermittent. Nothing is getting hot either.
Anybody have any ideas?
Thanks
 
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Mark,

My Jet makes a few wierd noises every now and then. But it is the live center at the tailstock end not the powered end. I sometimes have to back the tailstock live center off just a little and then go at it again.

[:I]
 
Mine does similar but to a lesser extent. The bearings are going bad. If I turn the chuck by hand using the wheel I can feel a slight clicking. At speeds this is a vibration/hum. Yours sounds similar and worse.

Mine is still "under warranty" but I'm planning on just changing the bearings myself rather than be without my lathe for however long it takes them to fix it.

GK
 
My problem is kind of strange. I don't have any strange vibrations or clicking either. Maybe those are something I can look forward to?
Do you have to have special equipment to change your own bearings?
 
Originally posted by mdburn_em
<br />.....It moves about 3 small marks on my dial caliper. thousandths.....?
Click to expand...

Yup.....three thousandths. How old is your lathe and does it get a lot of use? Is that movement axial or radial? I don't know what the specs are; but that much radial movement is probably too much.....read bad bearings. Call JET and ask them what the play should be unless someone comes along who knows for sure. Sometimes belts will make noise when they start to get old and dried out even if they aren't frayed and cracked. i think this probably applies more to V-belts than to the Poly-Rib belt that the JET mini uses; but if you have some belt dressing for your automotive belts, it wouldn't hurt to dress up your lathe belt as well. Don't overdo it or too much of the belt dressing might attract sawdust and cause a buildup.
 
Originally posted by Randy_
<br />
Originally posted by mdburn_em
<br />.....It moves about 3 small marks on my dial caliper. thousandths.....?
Click to expand...

Yup.....three thousandths. How old is your lathe and does it get a lot of use? Is that movement axial or radial? I don't know what the specs are; but that much radial movement is probably too much.....read bad bearings. Call JET and ask them what the play should be unless someone comes along who knows for sure. Sometimes belts will make noise when they start to get old and dried out even if they aren't frayed and cracked. i think this probably applies more to V-belts than to the Poly-Rib belt that the JET mini uses; but if you have some belt dressing for your automotive belts, it wouldn't hurt to dress up your lathe belt as well. Don't overdo it or too much of the belt dressing might attract sawdust and cause a buildup.
Click to expand...

Randy,
I'm taking a stab that axial means extending through and beyond my lathe bed. Anyway, that is the direction of movement. It is the direction the shaft would have to move if I were to remove the whole thing to replace my belt. I did not see any measurable movement radially (parallel [?]).
The lathe was used last spring and summer but then I stopped when college began again this fall. I've only made pens with it and I suppose I may have made about 150. I didn't get into the shop until just a few weeks ago. So it sat for about 9 months.
I'm, uh, very much NOT mechanically inclined. Spent most of my adult life chasing electrons. I have some belt dressing I bought because I want to fix up my dad's old Shopsmith. (If you only knew what a punch line that is...) How much is too much? I'm assuming you would want to apply it to the inside of the belt. Is it kind of a rubber rejuvinator? You mentioned build-up. would that occur in the lathe pulley's?
Thanks for your help.
 
One day I was CERTAIN I had bearings going out or a belt about to go or some other terminal problem with my lathe. Something made me stick my finger out and touch the little door you open to change the belt speed and the noise stopped. All that worry for nothing.
 
1. As Kenwc mentioned - Minute' variations in belt tensions cause them to vibrate more on less; if more, then it can hit and barely rub the belt adjuster door - and cause that sound.
2. Bearings
3. If the pulleys are not pressed on, but are tightened with set screws, they (set screws) could be loose. I have had this happen on a couple of my tools over the years and they do make a turkey call kind of squeal. This one becomes evident pretty quick though, because of the slippage too.
 
Originally posted by leehljp
<br />1. As Kenwc mentioned - Minute' variations in belt tensions cause them to vibrate more on less; if more, then it can hit and barely rub the belt adjuster door - and cause that sound.
Click to expand...
I had both doors open trying to identify, EXACTLY, where the sound was coming from.

3. If the pulleys are not pressed on, but are tightened with set screws, they (set screws) could be loose. I have had this happen on a couple of my tools over the years and they do make a turkey call kind of squeal. This one becomes evident pretty quick though, because of the slippage too.
Click to expand...

Hmmm, now that makes me think. I know I've been having "slipping" problems but I figured I didn't have the knob tight enough. (Although, any tighter would be creating out of round pens.) I've also been using my new Beall Collet chuck and assumed (rightly) I just don't know what I'm doing with it.
I do have the set screws on the pulley AND if it had slipped a little, that could be causing my (axial?) play. I'll have to check that when I get some time to go to the shop.
Thanks
 
Originally posted by mdburn_em
<br />.....I'm taking a stab that axial means extending through and beyond my lathe bed. Anyway, that is the direction of movement. It is the direction the shaft would have to move if I were to remove the whole thing to replace my belt. I did not see any measurable movement radially (parallel [?])....
Click to expand...

Axial movement would be movement would be movement along the axis of the spindle.(can only be horizontal movement) Radial movement would be movement along a radius of the spindle. (can be any direction but is always perpendicular to the long axis of the spindle) If I understand you correctly, you have radial movement and that is the type of movement that you DON'T want. Could indicate bad or failing bearings


Originally posted by mdburn_em
<br />.....The lathe was used last spring and summer but then I stopped when college began again this fall. I've only made pens with it and I suppose I may have made about 150.....
Click to expand...

That is really not enough "mileage" to suspect bearing failure under normal circumstances; but sometimes does fail after only a very short period of time so we can't totally rule a bearing problem. Lots of times, if the bearings are bad enough to make noise, you can feel a sort of rough or gritty feeling when you turn them by hand. The spindle should turn as smooth as glass. Any roughness and you have a problem.

Originally posted by mdburn_em
<br />.....I'm, uh, very much NOT mechanically inclined. Spent most of my adult life chasing electrons. I have some belt dressing I bought because I want to fix up my dad's old Shopsmith. (If you only knew what a punch line that is...) How much is too much? I'm assuming you would want to apply it to the inside of the belt. Is it kind of a rubber rejuvinator? You mentioned build-up. would that occur in the lathe pulley's?
Click to expand...

I would take a small glob and rub it between your thumb and finger until until you have just a thin film on your fingers and then rub them on the belt.....inside of belt and edges. Avoid getting any "globs" of dressing on the belt. Yeah....the buildup could be on the pulleys or the belt. Rejuvenator...?? I'm not exactly how the stuff works or exactly what it does; but it does make the belts perform better and last longer.


Still would be a good idea to call JET and get their input although you will spend a long time waiting on the phone...if my experience is any indicator. Their customer service by phone is lacking. If nothing else you will get a flag raised on your lathe in case you need to make a warranty claim.
 
Strange Lathe noises,
When I was a kid mechanics used a long screwdriver and rested that on various engine areas putting their ear to the top end much like a doctor with a stethescope,well believe it or not it will isolate the precise area where noise comes from,then you have a better idea how to proceed.Some noises vary with revs,some only at certain revs,called harmonics. If you proceed with caution and help of a friend who knows then deal with the supplier.
If you strip and or mutilate kiss your warranty goodbye.
Wish you well please take care otherwise it would be like operating by phone with a burst appendix,brave but unwise.
Peter
 
I took the hand wheel off and then I loosened the upper pulley so I could put the shaft out (in an axial direction, right?) The part I had seen moving when I pushed on the hand wheel was the bearing moving left to right. There is absolutely no play, radially. The set screw had been tight and there wasn't any slipping of the upper pulley, like I was kinda hoping. I decided to reassemble the thing. It went together just fine and I discovered I cannot tighten the hand wheel to the point that it binds. It tightens until it runs out of thread and that's it. It's still about a 16th or more away from the body.
Anyway, the turkey has gone into hiding most of the time and only lets out the occasional gobble. It seems obvious that something I did changed things but I have no idea what. I received an email from Jet the next business day and they offered to send me bearings even though I indicated I had lost my receipt. I don't think it's bearings because there is no play, no grinding and when I spin it by hand, it spins very easily.
I will try and see if I can't pin down the source of the noise a little better. Thanks for the suggestion.
 
Mark: Would I be repetitious if I suggested you have found your problem? There is supposed to be a small washer.....JET calls it a wave washer.....between the handwheel and the headstock to apply some axial (there is that word again[:D]) pressure on the spindle. I just gave a careful look at my mini and when I tried to wiggle my spindle, axially, there was no discernible movement; but with some strong axial pressure on the handwheel, there was about 1/32" of movement.

When you removed your handwheel, did you find a wave washer on your lathe? If so maybe it was responsible for the noise and just the act of removing and replacing the handwheel realigned the fit and reduced/eliminated the noise? If you did not find such a washer, you probably need to have Jet send you one.

If you do have a wave washer in place and still get an occasional “chirp,†you might want to apply a single drop of lubricating oil to the washer or remove the handwheel and apply a tiny amount of grease to lubricate the washer. You don’t wast a lot of lubrication at that point or the lathe may sling it off when running at high speed.

There was another post about this washer recently and I think it, too, was about a noise; but don’t remember for sure. I’m going to see if I can find it or maybe someone else remembers it??

In any even, I think you may have found your difficulty.
 
I did notice that springy, sorta bent, washer. I did put it back on too. I will try what you said. Would you suggest some light oil like you might put in an air compressor? My dad left me varying weights of oil up to 90. Not sure when I'll ever use that. He had it around for farming. Anyway, I'm going out to the farm today, so I'll giver 'er a go.
 
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