[OP]
Contributor
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
Member
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.
Retired - when every day is Saturday (unless it's Sunday).
Member
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
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 .
Last edited by john taliaferro; 05-08-2016 at 9:29 AM.
Member
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.
Member
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.
Contributor
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.
[OP]
Contributor
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
Member
Some things to look for:Originally Posted by Jim Colombo
* 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?
_______________________________________
When failure is not an option
Mediocre is assured.
Member
What are you using to hold the blank ??, a chuck ?
If a chuck, are you using a tenon ??
Have fun and take care
[OP]
Contributor
Yes, and I checked the chuck with smaller pieces.
Member
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
[OP]
Contributor
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
Member
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.
Member Turners Anonymous Pittsburgh, PA
Member
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
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