Nova Titan woodworm - what am I doing wrong?

[Dean Center]

Even though Mark is using the newer worm screw with the flange, his second picture perfectly shows how the slide holds the boss. Lou's picture above confirms that the screw is held in by the slides and the jaws do not hold the screw. Thank you for illustrating what I've ineptly been trying to say. I've used the screw on hundreds of blanks, and it's entirely possible there have been times I didn't have it lined up just so. If working as designed, the boss shouldn't get burnished, so that may be from me not getting the screw exactly right, or the Nova chucks may not secure the screw as well as intended. I have used it on blanks up to 10 or even 12", maybe 5 inches deep which could have overpowered the design without me realizing.

Best advice from me is, as Bill Blasic says, get the right screw for the right jaws.

 

[Mike Peace]

Clearly the Power Grip jaws you have are deeper than the ones on my Titan II which does allow the screw to protrude 3/4" as shown in the picture. I will note that I am actually showing the Record Power Jaws that are virtually identical to the Titan II jaws. It appears that Teknatool failed to consider that when it decided to send the original Titan II screw instead of making a new one.

An option might be to use the Teknatool 75mm bowl jaws with the longer screw. But because they are only about 1 3/8" deep compared to the deeper 1 1/2 Powergrip jaws the screw protrudes just longer than the last thread so you will need to use a spacer. It will still provide a stronger hold than the normal 50mm jaws with the short screw.

 

[Bill Blasic]

If you move that up and grip by the jaws instead of the jaw slides is how I used it which brought it up to the height of the screw in the smaller chucks. And as I said it is not the best solution as it could pull out. I never used it on bigger pieces and I have no need to do so. Here is a pic of 3 Titans on the left is the original Titan with the screw tightened on the boss with the jaws and it is the right height that you would normally use a wood screw but not the safest. The middle Titan Ii with regular jaws and a normal safety screw which works out to be normal. The Titan III on the right has the new Titan jaws and the longer screw that came with it and it is almost too tall but will work (I would use a plywood spacer myself). There is no doubt that Teknatool should remedy the situation but I can almost guarantee they won't because they would have to supply every person who has the chuck with the right screw. Send this to Teknatool.

 

[Lou Jacobs]

Bill, that is what I’ll do, with caution, when I want to use these jaws, otherwise as Mike suggests, shorter jaws with a spacer. It I were a welder and had a metal lathe (big ifs) I’d weld an extension on the screw and then turn it all down to the right size. On a positive note, this chuck turns much truer than my smaller Nova chuck which has an insert. No apparent runout (as measured by eye - no dial indicator either).

 

[Lou Jacobs]

So here’s one last idea that’s probably more trouble than it’s worth. How about drilling the end of the screw and tapping it for a machine screw with which to mount a washer slightly larger diameter than the head of boss? Secure screw with epoxy or thread lock. Then it can be used as Bill suggests, with just a bit of protection against being pulled out.

 

[Doug Freeman]

Lou, in the pic it appears the screw is not actually “free” of the jaws. It appears the jaw slides clamp the screw head, which prevents the screw from rotating, and the jaws extend over the top of the screw head preventing it from being pulled out. The center of the jaws should not clamp the screw shaft, as this prevents the inside end of the jaw slide from clamping on the screw head. Note in Mark’s pics the jaws do not clamp on the screw shaft. Your original path of machining down the length of the head is valid.

 

[Lou Jacobs]

Yes Doug, except to machine it down enough to have a useful section of threads exposed above the top of the jaws, I think there’d only be about 1/8” of head (or boss, to use their term) left. I’d be a bit queasy about having that little anchor.

 

[Doug Freeman]

I agree. There is some possibility of a large blank creating problems.

 

[Gerald Lawrence]

I have SN II and a G3 made for Delta. This does not relate to the original question but is to show that Nova does make different length woodworm screws. The jaws on the Delta G3 have jaws 1 inch deep and the screw for it is longer than the SN2 screw. So they do make different screws to accommodate the different chucks.

 

[Leo Van Der Loo]

Had a look at the hold of the woodworm screw in my 25 year plus old Oneway Stronghold chuck, well as I expected the Oneway design was much better designed and the hold superior to what was shown above.

Both the basejaws and the jaws hold the woodworm screw, holding the screw with no wiggle room, I tried to se if either the base jaws or jaws were holding the same by just loosening , but found that they were both holding.

The jaws are also machined with a step so the woodworm is held solid with the jaws holding it between the head/boss and the flange on the shaft, keeping it centred.

I have and do use the screw sometimes, but with larger pieces of wood I do use the faceplate most times, Oneway does have a longer and also LH thread woodworm screws, very nice quality and solid.

 

[Lou Jacobs]

Thanks for checking on this Leo. I wonder, but am not optimistic, if the longer Oneway screw you mention would work with my Nova chuck and jaws. I’ll look into it.

 

[Bill Blasic]

Like I said in another thread I have two Oneway Chucks and both of the screws that came with them snapped while using them. I have over 20 Nova screws but I have used the same one I got with the chuck that came with my DVR about 19 years ago and I start almost every piece on the screw and it still looks like new.

 

[Leo Van Der Loo]

Like I said in my previous reply, I can hardly believe that one would be able to break these very sturdy and wel made screws that are more robust than the Nova screws would break, even twice ??

I also know I would trust the Oneway woodworm screw more than the Nova ones, and would hardly think that anyone would snap even one of those off.

Like they say, maybe you get what you pay for !!

 

[Bill Boehme]

Thanks for checking on this Leo. I wonder, but am not optimistic, if the longer Oneway screw you mention would work with my Nova chuck and jaws. I’ll look into it.

My opinion is that you would be much better off by getting normal height jaws. The distance between the top of the boss and the "flange" on the Oneway screw is 6.6 mm and the "floor" of the upper jaws is ~8 mm thick. There is a counterbore in the upper jaws ~1.4 mm deep so that the jaws fit snugly between the boss and the flange. BTW, the diameter of the screw between the boss and the flange s 15 mm. As shown in Leo's picture, the upper jaws tightly clamp around the screw shank, and as best as I can tell the base jaws also make contact with the dimples in the boss of the screw. It would be quite a coincidence if all these dimensions were compatible with Nova jaws.