How much error is to be expected on a rotary table in terms of eccentricity? With a #1 Morse tapor arbor fitted into the thing (the end of the arbor is about 1 inch diameter) I get a peak to peak eccentricity of 0.004 inches. Is this a normal level of error? The error does seem to be mainly semi circular, although there may be a bit of quadrantal error as well: that's a lot less, though. I did have things a lot worse: the mounting plate supplied for the three jaw chuck proved, on inspection, to not have had the holes for the bolts holding the chuck down to have been counterbored sufficiently. As a result, the chuck wasn't square to the table. Another reason why I'll never go back to that supplier for anything but spares. A colleague who had multiple problems with that firm now claims that the Hitchhiker's Guide to the Universe worst curse of 'Belgium, man Belgium!' should actually be 'C^&*$£ UK Limited'! Peter Chadwick Swindon MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.