Putting Jaws on a Nova 2 Chuck

Jay Lock

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First of all, I apologize for what will be an Endless series of questions but I'm out here all by my lonesome except for my cyber buddies. So I'm sure that there will be a lot more questions as I puzzle this thing out. Sure is different from going to a workshop where everything was set up :huh:!

While I'm waiting for the stand to arrive so I can set up the lathe I thought I'd clean up the chuck and add the jaws to it. I have been following the directions EXACTLY and are sure that I have the proper jaw on the proper number on the chuck. The directions say to Nip up the machine screws (I guess that is New Zealand speak for tighten :D), then back off a half turn, then carefully close the chuck so the jaws are touching with even pressure, then tighten down all the screws.

When I do this, the inside of the four jaws don't appear to form a circle, but a kind of "round square" . Is that because the geometry of the jaws has to accommodate a range of travel and the interior part isn't important?

I haven't tightened anything yet, maybe a picture will help so someone can tell me if this normal or if I've got a lemon.

Off to the shop with the camera

Thanks
 
Jay, if I am understanding what you are saying, the jaws are doing exactly what they are supposed to. In contraction mode, the jaws make full contact, i.e. completely touch the wood throughout their inner circumference when the jaw is ever so slightly open. This allows the full surface of the inner circumference of the jaw to bite into/grip the tenon or spigot of the piece of wood. That is the optimal point of contact when the entirety of each curved jaw surface contacts the wood.
 
When the jaws on my PSI chuck aren't fully closed, they give that "round square" appearance also. But, maybe, that is because it is Chinese made. :rofl: Actually, since each of the jaws is a fixed curve, the inner 'circle' can't be perfectly round except at one position. And that is closed all the way. Once you get the "nipping" part figured out, you should be good to go round and round. :)
 
Mike

Thanks for the help

Here are a couple of pics, one with and one without a flash.

Do they look ok? Maybe I'm being too anal, funny I've NEVER been accused of that! :rofl::rofl:

But the instructions say that if they aren't properly aligned I"ll have runout problems so I'm trying to avoid potential problems as I start turning

Thanks

Jay
 
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Thanks guys!

On to the next question, the manual says that all chucks and faceplates must have a "side locking function"

I put the adapter thread piece in the chuck and then installed the fiber insert and the set screw on the chuck

But I don't see any similar feature on the adapter to lock it onto the spindle? Did I receive an improper adapter? It went into the chuck smooth as silk and the set screw locked down just fine but if I run the lathe in reverse (for sanding?) then won't the chuck spin off the lathe spindle unless it is locked on. I can see something like they are talking about on the face plate that came with the lathe.

Jay

Got to find some turners here so I won't bother you guys!
 
Jay, your chuck jaws are just fine, they like all other makes are designed to give best grip without marking the wood at a specific diameter (maximum area contact)

If you set the jaws at this diameter you will find they form a perfect circle. You should aim to turn your spigots and recesses to these dimensions for best grip.

Although these are a different make you can see what I mean in In this article

EDIT: 50 mm (standard) Jaws for Nova & SuperNova chucks; Contracts onto 45-65 mm spigots. Expands into 50-75 mm dovetail recess.

Optimum contact area is in the middle of these ranges.
 
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...but if I run the lathe in reverse (for sanding?) then won't the chuck spin off the lathe spindle unless it is locked on. I can see something like they are talking about on the face plate that came with the lathe.

You are correct Jay, If your lathe is reversible then it is essential that you have some form of locking to prevent the chuck loosening, at high revs it will take milliseconds to come off the spindle.

I had to drill and tap the rear collar on my chuck to fit a locking screw when I converted the lathe to provide a reversible mode.

On the old style super nova chuck I had I don't think the hexagon flange nut was wide enough to fit a locking screw.
 
Chas

Thanks so much for the reply and the article link! Great idea. I have an email into the place where I bought the lathe and chuck, they know what I was buying and its reversing capabilities, perhaps a stock person pulled the wrong adapter.

Jay
 
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Chas

Thanks so much for the reply and the article link! Great idea. I have an email into the place where I bought the lathe and chuck, they know what I was buying and its reversing capabilities, perhaps a stock person pulled the wrong adapter.

Jay

I think you will get quite a few people tell you that they do not bother with a locking screw when reversing the lathe, you may get away with it for a long time, especially if just sanding.

But I for one would not risk it, a block of wood leaving the chuck is bad enough at speed, the added weight of the chuck bouncing around between toolpost, bed and anything else in the way is not nice.
 
Chas

I agree, and the manual says that it Must be locked on as well, so I think I just got an older adapter.

Jay
 
Would placing an appropriate bolt onto the spindle first, followed by a split-helix lock washer and then finally the chuck (assuming there is room enough on the threaded drive shaft) be a sufficient locking mechanism?

I am totally new to turning and have no idea if this would be safe or not, that's why I'm asking. In other words, don't do this and get upset at me if you wind up with a chuck sticking out of your head.
 
Mark, the problem with putting anything other than a slim smooth washer between the chuck and the spindle nose is that the chuck relies on the location spigot on the spindle for alignment; there is no guarantee that a chuck just located on the threads will run true so anything like a lock nut or washer will not work.
 
Mike

Thanks, I am trying to get Craft USA to make it right on the order (other than that they were super)

Jay
 
My G3 has the inset with the locking screw, I lock it down when ever I use it, imagine my surprise when the new BIG titan chuck came, and there was no locking screw on it, I was shocked!

But rather than fuss with the mess of returning it and such, I'll just drill and tap a hole for a screw in the insert I have, but if I was in the US, I'd return it and get the right insert.

Cheers!
 
..... I'll just drill and tap a hole for a screw in the insert I have,

Exactly what I was able to do with my Axminster Chuck Stuart, although it was actually in the backplate collar not an insert.
Unfortunately the standard inserts for the nova do not have enough meat in them to get a sensible sized screw in them.
Also dependent on the thread fitting* some nova chucks do not have an insert and are directly threaded, there is no way to lock them.

*Larger sizes
 
Well, I did not say it would be "Easy" Chas :D

The insert on my G3, the hole is not on the flat, but on the tip,or one of the corners of the nut part of the insert. The insert has a grub screw that keeps the insert in the chuck on both of my chucks, the Titan and the G3.

chuck_grub_screw.JPG

As you can see in the pic above.

When I do the deed on the Titan insert, I'll take pics. :wave:
 
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