How much runout is acceptable in a wood lathe?Ive noticed my mandrels vibrating lately and checked runout this afternoon.I chucked a 1/2 in. dia center drill as close to the chuck as possible and checked with a dial indicator as close to the chuck on the surface of the bit as possible and got .035 runout. The tailstock live center point and the center drill point in the chuck are also a shade off center when brought together.

Wood lathes are not intended to be as accurate as fine machine/tool lathes, however, they shouldn't be off by much.

Is your headstock adjustable for position?

Also check your mandrels - some are not perfectly straight and the smaller diameter ones are prone to whip out of round when spun fast or in longer lengths.

...............

Bruce,
As you well know, the less runout the better.
Anything that you can do to minimize runout will let you deliver a better product.

Roger

This is an older sprunger lathe.The chuck is a nearly new barracuda I bought less than 6 mos and probably turned a half dozen cork grips on it.The particular mandrels are a couple Lynn made special for me 16in. long and 5/8 and3/4 dia.It does the same with whatever is in the chuck.Ive had the shaft out of the headstock to check bearings and replaced both though they didnt seem bad.The head stock shaft is probaly 8 in. long and mounts chuck with a 1in. thread .Idont see how it possibly could be bent that short and dia. that big.Is it likely the chuck could be out of round.I have no adjustment on the headstock as the bed and headstock housing are cast together.

Sprunger made a very good lathe.

Take the chuck off and insert a center into the MT on the headstock, and the same on the tailstock. Run them up close and see if they meet dead on. If so, then it's your chuck. If not, then it is what it is.

...............

Bruce, With respect to lathes and tail stocks:

One of the big reasons to use MT inserts for both head stock and tail stocks is that it is easier to get very small runouts with MT inserts in the lathe.

On the other hand, when you have a thread on a head stock and a thread on the inside of a chuck, it is much tougher to have the same small run out.

If you find, that when using a well made pointed insert on both the head stock and tail stock and find that you have little run out, but find that the run out increases with the chuck screwed on, and if the chuck is a high quality chuck, the most likely cause for the run out is the threads that are on the head stock.

Good luck
Roger

Tom I told you wrong,the headstock is bolted to the bed casting.A few minor adjustments and got that dead center with the tailstock.The runout is still a pretty good bit(.030) or so out with the 4 jaw chuck.Roger you are right with my jacobs chuck on the #2 taper it is only .003-.005 out.I thought I was buying a quality chuck in the barracuda.Maybe Im expecting too much.I guess my next question is can I buy a 4 jaw chuck on a taper instead of screwing on.Is thereb a better quality chuck with screw on threads?

Most all the chucks thread onto the lathe headstock spindle. But while none of these will be as accurate as say, the really expensive chucks sold for larger machine lathes, there are very good ones out there. I very much prefer the OneWay Talon. It costs a little more than the Barracuda, but I'm confident it's a better chuck.

................

Tom is there somewhere you prefer to buy it?What jaws do I need ? I believe you have said you used the #1 spigot jaws a lot.Im looking at the Oneway talon safety chuck.Is that the one you have?

OneWay Talon (never heard it called "safety") is the one I use. The Spigot jaws are great. The Talon has a very generous capacity.

.....................