Any ideas on tailstock alignment?

[Brian Kent]

I am having a little problem with tailstock alignment on my Grizzly G0800. I have notified tech support and will keep on working with them. First time around they said there was no means of adjustment, but to check debris / cosmoline. After cleaning there was an improvement so I thought the problem was over. But there is still this misalignment. It only makes a difference on tall chalices when I am trying to keep the cup stable when turning the outside of the chalice.

Any ideas here? I will definitely keep moving with Grizzly tech support.

Here are pictures of the misalignment and the alignment plates on the bottom. When I loosen the 3 hex screws, the plate still seems immovable

[Roger Chandler]

Level your lathe bed front to back, side to side, diagonally in both directions.........99 times out of a hundred, it is one leg pushing on the ways more than the others. A small high spot on your concrete floor can exert just enough torque to affect alignment of centers. Loosen all feet, then do the level thing, working diagonally first.....this should take care of it... it is best to level with the headstock and tailstock off the ways.

[William C Rogers]

You are fairly close. Any chance you have another spur center? Just to verify I would change to a sour center and check. Then reverse them and re check. That will tell you it is the lathe for sure. That will take any problem with the centers out of the picture. I just never liked checking with a rotating center.

[Brian Kent]

This is why you all are miracle-workers. I had not thought of either issue. I can see that the lathe bed is just a little off-level. I will adjust that, but I am not nearly powerful enough to remove the headstock :)

When I put a spur center in the tailstock, it was a much better alignment. That tells me the issue is the live center. I will ask grizzly for a replacement and/or buy another. If I buy another one, do you have any recommendations?

[Thom Sturgill]

Brian, do you know what 'winding sticks' are? If not google them. Easy way to check for twist in the bed. Lyle Jameison has a good video on adjusting the feet. For the live center, Oneway, Robust, and Jet/Powermatic all make good ones - and all work with standard accessories.

[Brian Kent]

Yes, I have used winding sticks but not on this. Than you for your idea and for the live center recommendations.

[ron david]

if you want a true reading as to how true it is you will have to use a dial indicator.. put on about a 6" f/plate and mount the dial indicator on it with a magnetic base and set the t/stock back 10 or n12 inches and take a couple different readings with the d/indicator rotating( by Hand) around the quill and also something in the morse taper that you can read that will be true(like in the pic). you will not find many standards relating to what the tolerances are, but the are about .005" at about 12" away from the faceplate. these are actyall old US army specs. that I dug up about 35 years ago and still have somewhere.( pre internet research). my General was .090" when I got it and had a terrible battle with and ended up in small claims court and they allowed me $1,000.00 off the price to fix it. I finally got it down to .0015"
http://imagizer.imageshack.us/v2/1280x1024q90/922/ZoVhII.jpg
ron

[Brice Rogers]

My Griz live centers are not very good. They only have a single bearing and they wobble a bit. I got one replacement and it was mismanufactured to the extent that it wouldn't turn. The next one was almost as sloppy as the first one. All three only had a single bearing. I would recommend getting a live center with at least a pair of bearings rather than just a single one. In fact, I saw one in some catalog or on-line that used three bearings. I suspect that it would be rock solid.

Roger's advice was good. Another variation or approach if that normal leveling doesn't work would be to (everybody take a deep breath now) adjust the feet and watch the alignment as you adjust the legs - - intentionally adding a little twist until the alignment is perfect.

[Leo Van Der Loo]

Don’t be too quick to blame the tailstock Brian, the headstock could well be the culprit, or both the headstock and tailstock.

Yes see if the bed is twisted, and correct that if it is, also move that headstock and see it that changes anything, just some dirt or wax under it will make a difference.

Also clean de MT openings in both headstock and tailstock, and install quality centers and than see if you are still not aligned properly, BTW I did not see if the points are off horizontally (higher/lower) or vertically (left or right).

[John K Jordan]

I am having a little problem with tailstock alignment on my Grizzly G0800. I have notified tech support and will keep on working with them. First time around they said there was no means of adjustment, but to check debris / cosmoline. After cleaning there was an improvement so I thought the problem was over. But there is still this misalignment. It only makes a difference on tall chalices when I am trying to keep the cup stable when turning the outside of the chalice.
Any ideas here? I will definitely keep moving with Grizzly tech support.
Here are pictures of the misalignment and the alignment plates on the bottom. When I loosen the 3 hex screws, the plate still seems immovable

Brian.

Did you try adjusting one of the legs? I didn't carefully read all the posts in this thread, but just in case: I have aligned lathes many times, most recently at a club demo where Mark St. Leger was turning on our Jet 1642. I never worry if the lathe is level, as in "perpendicular to the line to the center of the earth" - the lathe will work fine on a slight tilt. It does matter if the top is not all in one plane. (This is also true for table saws, etc.) Cast iron is actually quite flexible and the entire lathe bed will easily twist if one leg is too high or low. I read an account of a demonstration at a machine shop showing how the bed of a large metal-cutting lathe deflected by pushing in the center with a hand.

To align, simply put points in both the headstock and tailstock, move them very close so they are almost touching, then crank on just one of the leg levelers. It doesn't even matter which leg to adjust but I usually crank on one at the tailstock end. In all cases, this brought the points into exact alignment. If the lathe doesn't have leveling feet, use a shim. BTW, this is an old, old established alignment method.

I only care about the alignment when the tailstock is quite near the headstock where it can really mess up things. The further away from the headstock, the smaller the angle of any alignment error. A small misalignment will have no practical effect when turning a spindle between centers.

In most cases the misalignment is horizontal and not vertical. If the misalignment is vertical and adjusting one leg doesn't fix it, there is probably a different problem such as a machining tolerance error or a burr. (I did discover once when swapping headstocks between two lathes of the same model that the machining appeared to be different between the two resulting in a misalignment. I didn't take the time to analyze it further, I just swapped the tailstocks too and got on with life.)

JKJ

[John Grace]

Perhaps I missed it but I don't see whether or no you mention if your headstock can rotate or not? I recently purchased Teknatool's alignment tool to solve an alignment problem on my lathe...loosened both 'ends', inserted the alignment tool into both the head and tailstocks, tighten and your done. Good luck..

[Roger Chandler]

When I put a spur center in the tailstock, it was a much better alignment. That tells me the issue is the live center. I will ask grizzly for a replacement and/or buy another. If I buy another one, do you have any recommendations?

My live center that came with my G0766 is just fine. I do have a Oneway live center that I purchased from another turner, who got a new Oneway lathe....he already had a Oneway center, so sold me the new one. I use it most of the time, but I also use the Grizzly live center as well. I have had no problems with mine. I would highly recommend the Oneway live center.......good stuff.

[Jeramie Johnson]

Sounds like you are getting great advice. I too received a bad live center, the replacement was much better. I use a oneway live center normally, love it, and also have a live jacobs chuck too.

[Leo Van Der Loo]

I am having a little problem with tailstock alignment on my Grizzly G0800. I have notified tech support and will keep on working with them. First time around they said there was no means of adjustment, but to check debris / cosmoline. After cleaning there was an improvement so I thought the problem was over. But there is still this misalignment. It only makes a difference on tall chalices when I am trying to keep the cup stable when turning the outside of the chalice.

Any ideas here? I will definitely keep moving with Grizzly tech support.

Here are pictures of the misalignment and the alignment plates on the bottom. When I loosen the 3 hex screws, the plate still seems immovable



About the plate under the tailstock, I looks like the screws hold it against the bottom and it is pinned there, meaning the pins hold it in place so it will not be able to move, something the screws would not be able to do.

Loosening the screws will therefore not let you move the plate, you would have to remove the pins, something I would not recommend you do.

[Larry Copas]

Another possibility. The tail stock may have been bored cockeyed for the quill. To check match centers with the tail stock quill retracted completely. Next extend the quill completely and match centers again. If they are different the tail stock is suspect. Also make sure the quill is locked tight before matching centers.

I find it hard to believe there is much error in the centers. A level bed on a lathe is very important, but most of the time the error would be measured in the thousandths.

[Brian Kent]

I have not had time yet this week to level the bed, but here is the photo with a fixed spur center. This is satisfactory.

[ron david]

cast iron can move
ron

[Jay Mullins]

Brian.............
I agree with what Roger and others have said about leveling the bed, it's very important. I would suggest that you use a smart ( digital ) level, it will b easier to use and more exact. They are available at most stores selling tools ( HD, Lowes, Sears, HF etc.).

Jay

[carl mesaros]

I have not had time yet this week to level the bed, but here is the photo with a fixed spur center. This is satisfactory.

Brian glad you have your alignment issue solved. I have the Laguna 2436 the same lathe as your Grizzly GO800. My alignment has always been spot on.
I did notice in your last picture of alignment the sawdust clinging to the outside of the headstock housing. Mine does the same and I'm somewhat concerned that oil from the bearings is leaking past the seals. Just hoping this is natural. I guess we'll find out if we experience bearing failures!
My lathe has had over two years of almost daily use. So far so good!