Changing jaws in a Nova chuck

[Derek Jewell]

Does anyone have any ideas on how to remove a fastening screw for a Nova chuck jaw when the allan key hole is damaged so that under pressure the key only rotates instead of undoing the screw?

[Tony Morton]

Hi Derick
I;ve had this happen a couple of times and to fix it I have used a about 3/8 drill and drilled the top of screw removed jaws then got remainder of screw out with pliers , next time adding some greese to thread and head of screw hope this of help .
Cheers Tony

[gatiep]

If you have a Dremel or similar, use the cutting disc to slot the countersunk head, unscrew with a screwdriver.
Cya
Joe

[Jim Carroll]

The most important point to this is to make sure that the holes for the allen key are clear of dust etc. The main reason you have burred the screw is that the allen key has not been able to go to the full depth of the hole so you are not acheiving a good purchase on the screw. This means the key is not going deep enough into the hole and spins out easily and damages the screw. The suggestion of drilling the head of is one of the easiest ways of getting the screw out. Just do not drill too deep , only enough to take the head of the screw . This leaves enough thread to get your pliers onto to get it out.

[IanA]

The problem with the allan key sockets clogging up with crud is ongoing.

If you don't clean the crud out when it is loose the allan key will compact it nicely, and form a hard plug. Guaranteed to stuff up your screw sooner or later.

I have a piece of bicycle wheel spoke, ground to a point at one end, for digging out the crud. Works a treat.

[Derek Jewell]

Got it out after many attempts, using a combination of your suggestions. Thank you all.

[Jackson]

Derek - I have a Nova chuck also and found the same problem you havbe identified. I think the screws holding the jaws on actually tighten during use and the small allan key you get with the chuck can't handles the job very well.

I have obtained (I think it was from Carbatec) an allan key on a T spanner (for want of a better description. The allan key is the correct size for the screws but is about 12cm long and is attached to a T handle, about 9cm long and 1 cm diametre. The handle is also plastic coated. This tool gives a great deal more purchase when removing the screws and eliminates stripping the heads.

As a honus the tool also fits my tool rest adjustment screw, so I use it frequently.

Hope this helps

[IanA]

I agree with Mark's comment about the screws tightening with use.

I only tighten the screws finger tight, but considerably more grunt is required to undo them.

I've never had any problem with them coming loose during use, so finger tight appears to be perfectly safe.

[Derek Jewell]

Jackson - Part of my eventual solution was to buy a set of metric Allan keys, take the best fitting one and fit in into a home-made version of the handle you describe (They only sell sets of the T-handles in Bunnings and I wasn't prepared to fork out $85 for one). A bit Heath-Robinson but effective enough, at least in the short term.

IanA - Finger tight does seem to be the way to go. I did (temporarily) lose one chuck screw in the shavings under the lathe but I don't know if it came out during turning or if I dropped it. Probably the latter, I would lose vital parts of my anatomy if they didn't come attached.

[barnsey]

All the above suggestions are good - should you get a really troublesome one though an easy out with plenty of WD40 will get seriously hard ones to give up. Just need to make sure you use the appropriate size bit, hole and force.

Jamie

[TonyG]

Happy New Year to all!

I have also had this problem with the Nova Jaw screws.

My solution is similar to the previous advice:

1. Tighten finger tight (use short end of allen key only). In the mechanical trades it is called "nip up". When you clamp onto your workpiece, the jaws will react against the screws, so they will not be loose during the work.
2. Buy a good quality allen key. The original "Unbrako" brand is best, but others are acceptable. (Blackwoods sell them).These will fit more snugly into the screw heads.
3. Follow the advice given earlier re cleaning out the sockets prior to using the key.

Happy turning in 2004

[Little Festo]

I've also found this to be a bit of a problem. My original allen key has developed a bit of wear so sometimes if one of the screws becomes difficult to remove I use another "newer" key and this seems to work well.

Has anyone noticed this? On my 50mm jaws the inner screw hole recesses seem to grip the tops of the screws. The diameter of the screws top seems to be slightly wider than the recess.


Peter