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Reece
7th Jul 2010, 11:05 AM
Hi all,

I have a Supernova 2 chuck, have owned it for about 8 months i guess. I've noticed that when i switch from a faceplate to the chuck to hollow a bowl, that the bowl is a bit wobbly.

it's as if the chuck is spinning off centre (hopefully i can explain this). If i was using a non-self centreing chuck and set it up to run off centre, the work piece would wobble up and down, but would still spin true on the horizontal axis. That is the issue i am having.

It may have been an issue right from day 1 and my untrained eyes didn't notice, or it may only be a new thing.

Is there any way i can fix this?

Thanks in advance, Reece

Big Shed
7th Jul 2010, 11:12 AM
There have been quite a few reports of incorrectly seating inserts in the Nova chucks. I had this problem with a G3 chuck, which was fixed by DJ slightly shortening the length of the insert so that it would seat properly.

Your problem may be similar, perhaps if you do a search on this you may get some more info on how to identify and fix this problem.

Here is one thread on the subject

http://www.woodworkforums.com/f8/chuck-99494/

It definitely sounds like your chuck is running out of round, putting a dial gauge on it would tell you by how much.

Ed Reiss
7th Jul 2010, 12:01 PM
Big Shed beat me to it Reece :cool: ...if you read the whole thread, it's pretty obvious that there is a problem with the inserts.

Manuka Jock
7th Jul 2010, 02:08 PM
This issue has come up of late with our lathes at the club .
Well I 'spose that its always been there , but I drew attention to it :U.
I read thru that thread that Big Shed gave the link to , and if there was a solution to the problem I missed it , unless it was the mention of trimming the excess off the threaded end of the insert so that chuck collar sits snugly to the hex nut of the insert.
Is that a go ?
And if it is , what one of our turning tools is the one to do it with ?

EX's Timber
7th Jul 2010, 03:12 PM
I read thru that thread that Big Shed gave the link to , and if there was a solution to the problem I missed it , unless it was the mention of trimming the excess off the threaded end of the insert so that chuck collar sits snugly to the hex nut of the insert.
Is that a go ?
And if it is , what one of our turning tools is the one to do it with ?

The insert for Big Shed's chuck was a smidgen to long and therefore it wasn't seating on the shoulder but inside at the end of the insert as it bottomed out.

All I did to his and mine that I had at the time was to grind a little off the insert till it fully screwed in to bear against the shoulder of the insert rather than the end of it.

If is indeed the insert being too long, you should be able to see a fine gap between the shoulder of the insert and the body of the chuck where the insert seats.

Manuka Jock
7th Jul 2010, 03:23 PM
The insert for Big Shed's chuck was a smidgen to long and therefore it wasn't seating on the shoulder but inside at the end of the insert as it bottomed out.

All I did to his and mine that I had at the time was to grind a little off the insert till it fully screwed in to bear against the shoulder of the insert rather than the end of it.

If is indeed the insert being too long, you should be able to see a fine gap between the shoulder of the insert and the body of the chuck where the insert seats.

Yep thanks , thats' what I meant .
Hopefully the amount to be ground off is the same with every insert , all 12 of them .
Looking at my own one that I have here at home , the amount is about 4 mil .

Big Shed
7th Jul 2010, 04:23 PM
Before you modify 12 inserts, let me add another chapter to this story.

The insert that DJ modified for me by grinding a bit off it is the 1"x8tpi shown here on the left.


141179


After grinding it was seating hard up against the G3 chuck and all run-out disappeared.


141180


I believe this insert was manufactured by Vermec, it was supplied by Carbatec with the Nova G3 chuck, no packaging with the insert so I can't be sure. It does however look similar in design to the Vermec insert I purchased recently for my VM120 chuck.

A little while ago I purchased a new lathe, which has a M30x3.5mm spindle thread, so I had to purchase a new insert. On the way home from H&F with the new lathe I stopped at Carbatec and bought a M30x3.5 insert for my G3 chuck, which is the one shown on the right in the first picture and is made by Teknatool. Notice that it doesn't seat hard up against the shoulder of the chuck, yet the chuck has no discernible run-out.


141181

Manuka Jock
7th Jul 2010, 05:16 PM
Cheers for that Big Shed.
With one of the lathes at the club , an XP , I took the chuck and insert off , and replaced them with a drive spur , brought up the tailstock , put a drive spur in and with the quill out to its fullest extent , lined the points up perfectly.
I then ran it up to 3500 revs.
Not so much as a whisker out. I then put the insert back on , along with a chuck and put the spur drive in that , and revved it up to 3500 . The wobble was easily seen , in both the chuck and the point.
I tried it with 3 different sized chucks and it was the same each time.
My conclusion was that the problem lies with the insert .
I have spare one of my own that I will trim down as a test run .

Calm
7th Jul 2010, 09:39 PM
HI,

My insert was the same as the one on the left, to machine mine down i fitted insert to lathe without chuck and with the lathe running - not that fast - i used the angle grinder then a file to bring it down to the desired length.

cheers

Reece
8th Jul 2010, 08:43 AM
interesting.

I'll sneak out tonight and have a look at my chuck to see if that might be the issue.

Thanks for your help.

Allen Neighbors
8th Jul 2010, 11:25 AM
The insert for Big Shed's chuck was a smidgen to long and therefore it wasn't seating on the shoulder but inside at the end of the insert as it bottomed out.

All I did to his and mine that I had at the time was to grind a little off the insert till it fully screwed in to bear against the shoulder of the insert rather than the end of it.

If is indeed the insert being too long, you should be able to see a fine gap between the shoulder of the insert and the body of the chuck where the insert seats.

DJ, The SN2 Chuck Manual, says the insert is supposed to contact at the end of the insert, not at the shoulder. In the pic in the manual, you can see a fine gap between the shoulder of the insert and the body of the chuck.

So you're saying that you ground it down, so it would seat at the shoulder? Maybe that's what I need to do. I've got a slight bit of runout. Just want to know if I've understood all of this...

EX's Timber
8th Jul 2010, 11:31 AM
DJ, The SN2 Chuck Manual, says the insert is supposed to contact at the end of the insert, not at the shoulder. In the pic in the manual, you can see a fine gap between the shoulder of the insert and the body of the chuck.

So you're saying that you ground it down, so it would seat at the shoulder? Maybe that's what I need to do. I've got a slight bit of runout. Just want to know if I've understood all of this...

Allen, refer to BS's post which I've quoted below, take note of which insert he said I ground and which isn't ground, then check to see what Insert you have.


Before you modify 12 inserts, let me add another chapter to this story.

The insert that DJ modified for me by grinding a bit off it is the 1"x8tpi shown here on the left.


141179


After grinding it was seating hard up against the G3 chuck and all run-out disappeared.


141180


I believe this insert was manufactured by Vermec, it was supplied by Carbatec with the Nova G3 chuck, no packaging with the insert so I can't be sure. It does however look similar in design to the Vermec insert I purchased recently for my VM120 chuck.

A little while ago I purchased a new lathe, which has a M30x3.5mm spindle thread, so I had to purchase a new insert. On the way home from H&F with the new lathe I stopped at Carbatec and bought a M30x3.5 insert for my G3 chuck, which is the one shown on the right in the first picture and is made by Teknatool. Notice that it doesn't seat hard up against the shoulder of the chuck, yet the chuck has no discernible run-out.


141181

rsser
8th Jul 2010, 12:18 PM
FWIW my Titan had a bit of run-out when I put a T/tool insert in for the new lathe. I ground back the tip a bit and the run-out was worse.

Only talking about a few thou in both cases so no drama.

I would say that Vicmarc and Vermec inserts are distinctly more solid and wonder whether it's poss to get a bit of a twist in a T/tool if you tighten it too vigorously.

Sturdee
8th Jul 2010, 01:08 PM
Not so much as a whisker out. I then put the insert back on , along with a chuck and put the spur drive in that , and revved it up to 3500 . The wobble was easily seen , in both the chuck and the point.
I tried it with 3 different sized chucks and it was the same each time.
My conclusion was that the problem lies with the insert .
I have spare one of my own that I will trim down as a test run .

Unless the spur drive is modified it would have a morse taper on it. Are you sure that the wobble is not caused by the spur drive not fitting properly but at a slight angle because of the morse taper ?


Peter.

Manuka Jock
8th Jul 2010, 01:16 PM
Unless the spur drive is modified it would have a morse taper on it. Are you sure that the wobble is not caused by the spur drive not fitting properly but at a slight angle because of the morse taper ?
Peter.

Yep , sure am sure . Absolutely sure . Sure as sure can be .:)
There was no wobble with the morse taper in the headstock or the tailstock , the wobble was when using the chuck .
I would not be looking at the insert if the problem was elsewhere.
Its' all there in my post

Big Shed
8th Jul 2010, 02:07 PM
FWIW my Titan had a bit of run-out when I put a T/tool insert in for the new lathe. I ground back the tip a bit and the run-out was worse.

Only talking about a few thou in both cases so no drama.

I would say that Vicmarc and Vermec inserts are distinctly more solid and wonder whether it's poss to get a bit of a twist in a T/tool if you tighten it too vigorously.

Ern, whilst I agree with you that the (suspected) Vermec insert is way more solid than the Teknatool one, it was the Vermec one that needed modifying to get rid of the run-out, not the Teknatool one for my Nova G3 chuck.

See the first photo in my post above.

Having said that, the Vermec insert I bought for my Vicmarc VM120 was perfect out of the box, and is even more substantial.

rsser
8th Jul 2010, 02:34 PM
Thanks Fred.

And of course my chuck was the Titan and other T/tool models prob vary.

This issue was thoroughly canvassed on another thread than the one mentioned so Reece, use your search skills.

Big Shed
8th Jul 2010, 02:55 PM
http://www.woodworkforums.com/f8/great-chuck-runout-debate-101129/

http://www.woodworkforums.com/f8/problems-my-nova-chuck-65234/

robyn2839
8th Jul 2010, 11:14 PM
oly a long shot , but are you putting the jaws in the right order?as in 1234. i put mine out of order and they ran out quite a bit.......bob