View Full Version : Chuck wobble

3rd May 2017, 03:26 PM
Team, I am currently using an early model Nova chuck with the counter rotating locking mech. I cut the dovetail tenon, turned the job around and clamped it in, but it wobbles to all b-ggery. When I grab the job, and move it up and down the entire chuck moves up and down :o. I was wondering if anyone could tell what would be causing this, could it be the adapter sleeve to the spindle? I wouldn't have thought it was wrong as it wouldn't go on otherwise, especially if it's the wrong thread. Could it be worn? It's not the job wobbling in the chuck, sorry no photos or sneaky vid to show the play.

the bud vase too now looks like I cut it with a butter knife.

any advice on what to check would be great.

3rd May 2017, 04:47 PM
Check that the flat on the back of the adapter is hard up against the register on the spindle .

3rd May 2017, 06:35 PM
Will do.

3rd May 2017, 08:06 PM
Is the adapter sleeve tight in the chuck?
My Vicmark 120 chuck got it self stuck on the headstock spindle. I had to use a 2 pairs of Stilsons and a lump of pipe over it to free it. As much as I didn't want to have to use the Stilsons, I was left with no choice. Also I don't know why/how it got stuck.

3rd May 2017, 09:05 PM
Could the bearings be worn out ?

5th May 2017, 02:10 AM
Thanks all, I will check each one on Sunday morn when next in workshop.

6th May 2017, 05:13 AM

The above advice is good, here is my method.

Remove turning from chuck, remove chuck from lathe spindle, remove insert from chuck if used to adapt to spindle.

Carefully clean all threads and especially all flat mating surfaces on lathe spindle, adapter and chuck. Lightly oil all mating surfaces and screw adapter tightly into chuck and mount chuck on lathe spindle. Put chuck on tight, with hand force, no tools.

If you have been using a plastic washer between chuck and spindle to keep it from jamming, throw it away. That may and probably will cause the chuck to cock on the spindle. The mating flat surface of the chuck against the flat on the spindle are what makes it run true. The threads just hold it on.

A long piece, as for a vase, mounted between centers and the dovetail cut will probably have the tailstock end flop around a bit when grabbed by the chuck. When mounting, put tendon into chuck and lightly close the chuck. Bring the tool rest up close to the tailstock end of the turning and rotate by hand. If the end is wobbling around, give it a bump with a stick of wood to center. When it is a s close as you can get it, tighten the chuck firmly. I like to have my dovetail deep enough so that there is a nice 6mm face to bear against the face of the chuck jaws. Most of the time that will make the part run true.

Check again to see if it is wobbling. If the timber is not of uniform density it may crush one side more than another and tilt the turning. This is more apparent on a long thin part than on a bowl as any tilt in the chuck causes more wobble the farther out you get.

To check for bad bearings, when the clean lightly oiled chuck is mounted on the spindle, bring the tool rest about even with the bottom of the chuck and about 150mm away. Use a stick of wood as a lever and see if the chuck moved up and down. More than a mm of movement means adjustment or replacement of bearings.

Sticking the end of a screwdriver on the body of the running lathe close to the spindle on front and back with the handle placed against your ear will let you hear the bearings. A whirring sound is good, crunching, grinding sound is not.

6th May 2017, 07:42 PM
Seeing it was only a bit over a week ago you turned your inlaid bowl without any dramas it's unlikely to be your bearings, more likely to be how your chuck is fitting.

7th May 2017, 07:24 AM
Seeing it was only a bit over a week ago you turned your inlaid bowl without any dramas it's unlikely to be your bearings, more likely to be how your chuck is fitting.

I know, it's very odd, I have turned 2 bowls on this unit and both have come out excellent. I did one using a waste block and had it tightened in to the chuck by the 4 corners and the inlay bowl using a screw chuck, I then cut a dovetail recess before reversing in the chuck. I also made salt and pepper shakers, not grinders as I know the tail stock is slightly out of alignment. Between centres is fine but the bud vase, wow what a mess on the inside of the lip.

inwill run through all the procedures advised from above and try and work it out.

7th May 2017, 05:06 PM
Unfortunately I couldnt take the insert out of the chuck, and the insert will not seat against the spindle fully, but after cleaning the spindle thread and the insert inside thread it was able to tighten up nicely and no wobble. So I will figure out a way to remove the insert from the chuck and clean even further and hopefully this enable it to sit thought upagainst the spindle shoulder. Thanks all for your advice. Unfortunately however, the record power tool test I was using at the time is a 2peice and I hadn't checked if it was tight first. Anyway it wasn't tightened up enough and it moved and hit the job...... needless to say job no more..... now it's unsalvagable. On the bright side, actually there is no bright side to that one.

thanks again.

8th May 2017, 11:00 AM
One of the flaws with Nova chucks is the chuck insert system and how they register on the lathe spindle and into the back of the chuck. The inserts are quite small in diameter so do not have a very wide registration surface, compared to say the Vicmarc inserts or Oneway Stronghold inserts etc. They also rely upon the thread and the nose of the insert thread to align the insert into the chuck body. So they can be prone to alignment issues if not well maintained and threads etc kept clean. Check out page 11 in this manual 411978