I have a WOBBLE!

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emtmike

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I need some help! I am using one of those PSI lathes that came with a starter package. It what I could swing at the time not knowing if I would like turning. The problem I am having is I have a wobble in the tail stock end of my mandrel. It’s a new mandrel on one of those adjustable mandrel MT2 that goes to the head stock. You know the one you loosen the nuts to lengthen or shorten the mandrel. Both my head and tail stock are clean. What I am thinking is maybe its my live center. Any ideas?:(
 
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Do you have a 60° live center??

There is a good article on Russ Fairfield's web site discussing ways to diagnose and deal with your problem. I will post a link later unless someone else beats me to it.
 
If you are not sure, it probably isn't. Did it come with the lathe or did you purchase is as a separate item?? If it came with the lathe, it is almost certainly a 30° live center.
 
A good way to tell, is the live center a large silver cone for the entire shape? Or is it black and a small cone point surrounded by a ring shape? The 2nd would be the standard point and as Randy says, it's just the 30.
I don't know why PSI doesn't put the 60 in the "Kit" since it's required!!!
 
Originally posted by martyb
<br />
I don't know why PSI doesn't put the 60 in the "Kit" since it's required!!!
Click to expand...

Marty,

Can you elaborate on this. Why is a 60* center required I turn on the center that came with my Jet 1236 and don't seem to have any problems.

jeff
 
Here is what I have. As well if someone could show me a good live center to buy that would be great. Thanks

I have deleted the pic because I was told it was to big and I have cleared it from my hard drive. I guess it loads to slow. By the way, whats dial up?
 
Jeff, I don't know what center comes standard on your Jet. But the one on the PSI lathes, as you can see in Mike's picture, don't fit the divot at the end of most mandrels. The mandrel actually bottoms out on that small ring and then "floats" around the centerpoint giving the wobble that Mike is experiencing. I know this for certain, I tried turning with the livecenter that came with my Turncrafter Pro. The 60 degree point straightened that right out.

Mike, I purchased this 60 degree live center from PSI.
http://www.pennstateind.com/store/lcentlt2.html
If you do some searching in the forums, you'll find mixed opinion about it's quality. You get what you pay for, but I haven't had an issue with mine after 4 months now. You'll find quality live centers all over the internet. There have been plenty of recommendations in the forums, its really up to you and how much you feel like spending.
 
I know for a fact that some live centers from the factory have wobble in them. My Jet lathe had one with a bad wobble. I would see if they wil replace, or as someone said, you'll have to buy a new one.
 
I had to replace mine that came with my Turncrafter Pro. I believe the center that comes with the Jet is nearly the same quality. (Not very hard steel and not 60 degrees.)
After I turned a couple of pens it developed the wear that yours did.
Replaced it with the same one Marty did and things are a lot better now. Also picked up one from the Little Machine shop for a spare.
 
Replacing the live center with a new one of the same kind that comes on most of our mini lathes will not solve the problem. As many have mentioned, a 60 degree live center is the answer. One like this:
http://littlemachineshop.com/products/product_view.php?ProductID=1189&category=

Most all of our suppliers sell them. I have two of the live centers from littlemachinehsop.com and I understand the one from grizzley.com is also satisfactory.

Do a good turn daily!
Don
Originally posted by emtmike
<br />Here is what I have. As well if someone could show me a good live center to buy that would be great. Thanks
Click to expand...
 
Mike: The picture you have posted shows a live center that is designed to be used with wood and not steel. It already shows serious wear and may very well be the source of your trouble. The little point in the center of the ring should have a cone-shaped configuration with a sharp point. Yours seems to have a stepped configuration with a dull point.

The centering hole in the end of the mandrel has a 60° cone shape and is designed to match, perfectly, the face of a 60° live center. Most LCs that come with lathes originally have 30° and don't match the mandrel center hole. They ride on the very tip of the point rather than on the "FACE" of the point and will usually wear out pretty quickly. The LC you have will still work just fine when used for turning wood; but you do need to purchase a 60° LC for use with your pen mandrel.

There have been a few complaints recently about the LC from the Little Machine Shop. I have one and it is working just fine; but if I were to need to replace it, I think I might go with the one from Grizzly.....haven't heard any bad comments about them so far.
 
Since it was brought up,
I purchased the 60 from PSI and I'm not happy with it. It has a little plate on the back that keeps unscrewing. It gets hot and makes noise. I've had it long enough that I don't feel right about attempting to return it. I'm going to buy one from little machine shop. Probably should have bought that one to start with.
Mark
 
Mark,
The little plate that unscrews at the back of the PSI center is a good thing. You can unscrew the back and take out the fiber bearing cover and repack the bearing.
I used a snap ring pliers to tighten it.
 
Originally posted by tas2181
<br />Mark,
The little plate that unscrews at the back of the PSI center is a good thing. You can unscrew the back and take out the fiber bearing cover and repack the bearing.
Click to expand...
Huh?
That sounds like something mechanical. I stick with the easy stuff like electronics, networking or programming. [;)]
Randy I'll try and get a picture of that. I've been ill for the last 2 weeks so I'm not sure when I'll be able to get out and get it. (Shops five miles from here.)[V]
 
I think I have a wobble in my tail stock too, but it should disappear if I lose a hundred pounds.[;)] Actually, my old lathe had one and it was so old, I just bought a new one.
Rob
 
http://www.freesmileys.org/emo/ad/thanks.gif[/img]
20073154509_THANK%20YOU.gif
 
I had a problem with my PSI lathe as well, first thing I checked was if the points of the spur drive and live center matched up (they did when the lathe was new). They didn't, but about 1.5mm. Turns out my lathe bed was cracked, and as the crack got bigger from use of the lathe, my problems got worse. I'd suggest you flip your lathe over and inspect the bed closely. PSI replaced the bed on my under warranty.

Cheers,
Draken
 
Tom: Thanks for posting those pictures. They were very informative. Kinda looks like that LC needs a little more grease??[:D]

Oh yeah.......and thanks for sizing the pictures to fit the format of this board. I don't know about others;but for my computer, the 640 pixel wide picture is a perfect fit!![^]
 
Randy,
You are very welcome. The picture doesn't show the grease very well but I may just put in some more anyway.[;)]
As for resizing the pictures I downloaded the Image Resizer from Microsoft Powertoys. It works great. All you have to do is right click on a pic and choose Resize and it will resize to the resolution you want and it will make a copy with (small) (medium) (large) in the name. You have to get rid of the parantheses to post. ( The ones above are resized to small.)
It is available at:
http://www.microsoft.com/windowsxp/downloads/powertoys/xppowertoys.mspx
 
I don't know about the more recent versions of Windows; but I can resize pictures in "PAINT" just fine without having to resort to a special program.

Question.....does the PSI LC come with any instructions or recommendations about a time interval for repacking the bearing?

And for whoever had the problem with the disk coming unscrewed, a drop of Loctite (blue) should solve that problem. Probably a dab of any type of glue would solve the problem.....wood glue, polyurethane or even the tinyiest dab of CA??
 
The LC didn't come with any instructions or recommendations. There is nothing on the PSI website either. Don't know what kind of grease is in there. Seems to be a pretty light/ clear grease about the consistency of vaseline. Any recommendations?
Once I tightened the screw on cover with the snap ring pliers, I didn't have a problem with it coming loose. It seemed just to come loose from the enertia of the rotation when I first used it. Probably just wasn't tightened enough.
As for resizing the pics I just find it a lot easier with the Image Resizer than launching a different program to do it- to each his own on that one.[:D]
 
Originally posted by tas2181
<br />.....Seems to be a pretty light/ clear grease about the consistency of vaseline. Any recommendations.....
Click to expand...

There may be better alternatives; but what comes immediately to mind is to pick up a small can of wheel bearing grease from the auto parts store.
 
Try "setting" the ring after you have tightened it into the device. By setting I refer to using a very sharp pointed punch and placing the point at the junction of the ring and the body and striking the punch with a hammer - not to hard - thus making an indentation/dimple at the two seams. I use that method all the time on wheel bearing lock rings that screw into place - like your example. It takes a bit of pressure to unscrew to re-pack the bearings later, but I have yet to have one open up on me after punching it. You can do the same thing if you ever have a bolt that vibrates loose ... just center punch the threaded end - if visible - and you get the same spreading of metal, thus locking the bold in place.

Fred
 
My Jet 1014 came with the 30 degree LC and I used it for a couple of weeks. It began to show unusually wear quite quickly. I ordered and received the cheap one from LMS. So far so good. Now I found out the mandrel I have, has a bend in it. The bend is where the threads begin on the tail end. The shaft is fairly strait, but that bend in the threaded section ruins everything.
 
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