Too much runout turning 13 in platters

Joe, I think some of us always get _some eccentricity on remounting. Even when remounting to the same tenon or dovetail. Maybe truing about an inch of the top edge before taking it off the glue block to remount may help to 'blend' the runout. Arch

Fortiter,

You didn't say, so I assume you are using your Nova with the standard 50mm jaws? That's probably asking too much of them. If you are using them in compression mode (gripping a tenon) you will have better results doing the opposite and using them in expansion mode (expanding into a groove so the outside edge of the jaws is doing the gripping). Be absolutely certain the top face of the jaws is bottoming out in the groove. Going to a larger jaw set will help considerably more. I use 5" jaws in expansion mode for this kind of thing.

-mike paulson, fort collins, co

I don't know if my method will help you with your setup but I will tell you how I have done it. I mount the blank on a wasteblock/faceplate. Turn the platter both sides, top and bottom up to the wasteblock. Remove the platter from the lathe, mount in a compression (donut)chuck, true it up and turn off wasteblock and finish last bit of bottom. I have done 10-14" platters on an elcheapo Jet1236 look-alike with rotating headstock and 17" on my big General with this method. The problem you are having is due to any error being multiplied by the diameter of the platter. If you have 0.005" of tilt in the chuck then you have 13x0.005" at the edge or just over a 1/16" at the edge. Billh

billh wrote: (clip) I mount the blank on a wasteblock/faceplate. Turn the platter both sides, top and bottom up to the wasteblock ^^^^^^^^^^^^ This method eliminates all runout from both sides of the platter, except for the part under the wasteblock. Since both sides are turned on one mounting, the thickness should not be affected by any runout in the faceplate. You can even reduce that to the vanishing point if you face off the waste block, and then glue on the blank without disturbing it. The tailstock makes a really good clamp.

Hi Joe,

I make a lot of the above mentioned platters. I make mine out of 1" red oak. I cut them round on the bandsaw and sand the edge. Then I mount them on Cole Jaws and cut the recess for the marble, leaving it a little proud. Then I turn the cracker groove around the outside and sand.

I am then done on the lathe,except for turning the cheese knife handle. I use a 1/2" roundover bit in the router table for the edge of the platter, and it's done. I can pop one out in about 15 or 20 minutes. I also sell a lot of them at craft shows.

Good luck and if you have any questions, ask here or e-mail me.

Phil Phil Axtell Central Florida Woodturners Space Coast Woodturners Orange County (CA) Woodturners