Test for bearings

[Jim Colombo]

I have a Delta 46-460 and I was wondering if anyone has a means of testing the headstock bearings? My lathe seems to run true with no load but I can't seem to get a round tenon on a 10" bowl so I'm thinking the bearing(s) may be bad in the headstock.

Thanks,
Jim

[Thom Sturgill]

Are you holding the piece between centers to cut the tenon? If so, you may have a problem with the centers not being aligned or the bed having a twist.

[Doug Ladendorf]

I'm guessing it's not the bearings. Here are a couple things to check though. When you grab the spindle is there any play side to side, or forward to back? When you turn the spindle by hand do you feel any rumble, slight hesitations or anything other than smooth rolling? Finally, you can use a stethoscope or even a screwdriver up against your ear and touching near the bearings while rolling the spindle. If you hear crunchiness it may be the bearings. Sealed bearings last about 30 years before the grease dries, so if the lathe is older than that it may be a good idea to change them anyway.

Doug

[john taliaferro]

Sometimes it helps to loosen the belt and put a face plate on to feel it . Does it rool smooth or tight and Chauncey like Doug said . You might just be flexing the spendel in which you need a bigger lathe for what your doing .

[david privett]

if you know anyone with a magnetic base dial indicator , it will tell you if your spindle has a wobble because of bad bearings. they are great for checking jointer knives also. I think harbor freight has them less than 30 bucks also if you can not borrow one.

[Ben Pierce]

You can take a long bladed screwdriver... put the blade on the machine near the bearing and hold your ear to the other end of the screwdriver. There is a telltale clacking sound of a shot bearing, but it takes practice to identify it.

[Ronald Blue]

If the bearings were bad enough to cause turning issues you would have no trouble detecting it by rotating the spindle and listening for roughness or laying your hand on the head stock and feel for vibration. Bearings generally will get noisy and rough before they get to the point of failure. As has been mentioned if they are bad then you will be able to feel the slop in the spindle. No indicator needed. I won't speculate on what is causing the out of round but it is not likely to be caused by bad bearings.

[Jim Colombo]

Thanks for all the input. I've done a few tests and found that under no load (nothing on the spindle) all seems to be fine. When I put the blank I'm trying to core on I get the wobble. So now I'm thinking it has something to do with the headstock. Any thoughts??

Jim

[Dennis Ford]

Thanks for all the input. I've done a few tests and found that under no load (nothing on the spindle) all seems to be fine. When I put the blank I'm trying to core on I get the wobble. So now I'm thinking it has something to do with the headstock. Any thoughts??

Jim

Some things to look for:
* Is the whole lathe wobbling? This would be caused by a blank that is too out of balance for the lathe or too high rpms.
* Is the headstock moving relative to the lathe bed? (loose bolts?)
* Is the blank moving relative to the drive center?

[Leo Van Der Loo]

What are you using to hold the blank ??, a chuck ?

If a chuck, are you using a tenon ??

[Jim Colombo]

What are you using to hold the blank ??, a chuck ?

If a chuck, are you using a tenon ??

Yes, and I checked the chuck with smaller pieces.

[ron david]

Thanks for all the input. I've done a few tests and found that under no load (nothing on the spindle) all seems to be fine. When I put the blank I'm trying to core on I get the wobble. So now I'm thinking it has something to do with the headstock. Any thoughts??

Jim
what type of chuck are you using to hold the tenon. is it a fresh turned tenon or one that has been sitting around for awhile how big and long is the tenon. when you install the tenon in the chuck does the tenon have a square shoulder where it rests up against the chuck. some people are also not as caring of their chucks as they should be and the mounting face may have a nick or something where it was hit against another hard surface; both mounting surfaces of the chuck and on the spindle should be true to one another when mated together.
bearings are simple to check. back of the adjustment of the drive belt until the belt lets the spindle move freely. that shaft should turn freely with no lumps or noises. there should be no noticeable side or end play. as mentioned prior, a stethoscope type set-up. I just use a dowel rod or stick and listen over the bearing housing while it is running. should sound smooth
ron

[Jim Colombo]

It's a OneWay 4 jaw chuck and I've taken it apart and reassembled just to make sure. It checks out fine. The tenons are fresh cut in some very wet Mesquite. The tenons made before I noticed the problem are round (measured with micrometer) but I still get the wobble whether between centers or on the chuck.

Jim


what type of chuck are you using to hold the tenon. is it a fresh turned tenon or one that has been sitting around for awhile how big and long is the tenon. when you install the tenon in the chuck does the tenon have a square shoulder where it rests up against the chuck. some people are also not as caring of their chucks as they should be and the mounting face may have a nick or something where it was hit against another hard surface; both mounting surfaces of the chuck and on the spindle should be true to one another when mated together.
bearings are simple to check. back of the adjustment of the drive belt until the belt lets the spindle move freely. that shaft should turn freely with no lumps or noises. there should be no noticeable side or end play. as mentioned prior, a stethoscope type set-up. I just use a dowel rod or stick and listen over the bearing housing while it is running. should sound smooth
ron

[David Delo]

If you checked out the chuck making sure all the jaws are in the correct position and the jaws are centered correctly........i'd say you probably got a piece of out of balance timber. Maybe a hidden void or more water in one section/side of the piece. I'd try a piece of known dry timber and put it in the chuck and see if you get the same results.

[ron david]

easy way to check that out is to put something in the chuck that is known to be true and put a dial indicator on it and turn it free hand and under power to see if it should run true. with a dial indicator mounted to the bed you will be able check what ever to your hearts content. you can measure side and end play in the shaft, you can check the shaft itself both externally and internally(morse taper) and the chuck. if one of those is out of whack, that will more than likely be your problem. dial indicators are and a magnetic base are not that expensive and are handy to have
ron

[Wes Ramsey]

I have one very similar to yours. The shaft on my headstock is ever-so-slightly bent, which is not a big deal for bowls and hollow forms, but it is noticeable when turning pens and when reversing a bowl it is slightly off axis. It doesn't sound like it could be anything else unless the bearing housing itself is wollered out, and I can't imagine how that would happen.

[ron david]

I have one very similar to yours. The shaft on my headstock is ever-so-slightly bent, which is not a big deal for bowls and hollow forms, but it is noticeable when turning pens and when reversing a bowl it is slightly off axis. It doesn't sound like it could be anything else unless the bearing housing itself is wollered out, and I can't imagine how that would happen.
1 grain of sand between the mating surfaces of the chuck and the spindle can make a change
ron

[Leo Van Der Loo]

It's a OneWay 4 jaw chuck and I've taken it apart and reassembled just to make sure. It checks out fine. The tenons are fresh cut in some very wet Mesquite. The tenons made before I noticed the problem are round (measured with micrometer) but I still get the wobble whether between centers or on the chuck.

Jim

Jim does the chuck seat securely to the shoulder of the lathe ??

Some lathe spindles are a little longer and when you install the chuck it does not seat right and tight up against the spindle shoulder, and then your chuck can move to give you problems.

The other thing that sometimes happens if that the tenon is so long that it seats against the inside of the jaws that can also cause trouble, your tenon should have a nice flat surface that seats against the chuck jaws front surface.

These are the most common problems with blanks held into a chuck and not turning true, HTH.

[Jim Colombo]

After I had the lathe removed from the bench and in the car I noticed the plastic washer I have on the spindle was a little ragged and based on what Ron said I'm wondering if that may either be the problem or at least make it worse. Anyhow I ended up bringing it in to the repair center. I'll let you know what they find.

Jim

[John K Jordan]

Do you belong to a club or have other woodturners nearby? Another set of eyes may quickly see the problem.

JKJ

[ron david]

After I had the lathe removed from the bench and in the car I noticed the plastic washer I have on the spindle was a little ragged and based on what Ron said I'm wondering if that may either be the problem or at least make it worse. Anyhow I ended up bringing it in to the repair center. I'll let you know what they find.

Jim
I would remove that plastic washer if you don't need it. it does make taking f/plates and chucks of easier but can lead to perhaps problems like you are having. is it supposed to be there or was it put there for protection in shipping.
everything should have a good machined surface so that they all align straight when put together. you will see in the picture that every mating surface is machined
http://imagizer.imageshack.us/v2/1600x1200q90/924/vtJZpd.jpg
ron

[ron david]

the chuck that I have there is an early Axminster 5" with 1 1/2" x 8 threads (late 80s). they didn't make them that size for very long. it took forever to get it. never thought that I was going to get it, I had ordered it direct as then were no dealers in NA at that time. I had seen the ad in FWW for them. I finally asked asked FWW to call them and they did. I finally got it
http://imagizer.imageshack.us/v2/1600x1200q90/923/zKk7Jp.jpg
http://imagizer.imageshack.us/v2/1600x1200q90/923/8quz9R.jpg
ron

[Jim Colombo]

I put the washer there to allow easier removal of chucks & faceplates.

Jim

[ron david]

easier is not always better as perhaps your current problem. the fit of the 2 machined surfaces ensures a good fit and without coming loose. the plastic washer doesn't give you that.
It is not the threads that keep chucks and faceplates running true but that connection when it comes together. threads are relatively loose,
ron

[John K Jordan]

I put the washer there to allow easier removal of chucks & faceplates.

When I first started turning I read about using a washer and bought some from a turning supplier, also made some of my own from various materials. I used washers for a while and had several problems. One, the washer didn't last long; two, the lathe didn't run as true; three, sometimes the chuck wasn't as securely fastened as I wanted. I ended up not using a washer and haven't used or missed it in 15 years.

I think it is important to keep the mating surfaces clean and lightly lubricated. The assumption that this will make the chuck come off accidentally is not true. My policy is to lightly lubricate all mating metal surfaces, including all threads. From the Teknatool SN2 manual concerning troubleshooting when chucks are difficult to remove: "Greasing of insert face and spindle can also help." And BTW, note the next note in the manual: "- Note - Use of washer could affect accuracy."

If you are not removing chucks with the big spanner wrench made just for that, I recommend getting one (for each lathe). With installing the chuck by hand and giving the last 1/8 turn or so a little extra twist with a flick of the wrist, I don't have chucks come loose and I have no problem removing them with the wrench. I think the key to this is in the calibrated flick of the wrist which must be learned - too little and the chuck is not secure, too much and it is hard to remove.

I cringe when I see someone loosen a chuck with the key, sometimes even by whacking with a mallet. I've bought a number of used chucks and a couple were damaged from this type of abuse. Using the wrench eliminates this possibility. In addition, if the chuck is the type with an insert, if you use the wrench all the force is on the insert. If you use the chuck key, the force is on threaded connections between the chuck body and the insert (and the set screw) and the lathe spindle.

BTW, the worst chuck abuse I've ever seen was from the guy who used a cheater bar on the chuck key. He may have also been the Incredible Hulk's brother. The chuck body itself was distorted from too much force. He had told me that one was a little tight and might need cleaning. Ha. Took me hours of careful rework to make it right.

JKJ

[Wes Ramsey]

easier is not always better as perhaps your current problem. the fit of the 2 machined surfaces ensures a good fit and without coming loose. the plastic washer doesn't give you that.
It is not the threads that keep chucks and faceplates running true but that connection when it comes together. threads are relatively loose,
ron

I hadn't thought about that, but now that you mention it I remember trying a plastic washer last year. Put the chuck way out of balance. I took it off and hadn't thought about it since.

[Jim Colombo]

Got the lathe back from the repair shop and they couldn't find anything wrong with it. I took it home and turned tenons on the blocks of wood I originally had problems with. Guess what!!!!! No problem. The only difference is that I didn't use the plastic washer on the headstock. All you guys that suggested the washer was the problem were dead on.

Thanks,
Jim

[Fred Belknap]

I have Oneway chucks and use to get some wobble when mounting a tenon bowl. I found that if I bring the tailstock up to the bowl and put pressure on the bowl it cured the problem. Don't use a point but just the end of the tailstock ram. I saw this problem on a U-tube video, some guy with a British accent, Batty I think. He was explaining the advantage of a dovetail compared to straight jaws like Oneway has. He never mentioned the brand of chuck but it looked like a Talon. I also agree not to use a plastic washer on the spindle.

[robert baccus]

Toss the plastic washer and buy a can of thread anti-siezing compound at an auto store. That,s what it,s made for. Go arounds do not always work.