Question about SuperNova2 chuck

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A while back I purchased a SuperNova2 chuck and a fairly complete set of jaws. A problem I ran into is that the coverage of tenon sizes is not continuous (definition: tenon to me is the stub of wood that the chuck contracts onto to hold the piece).

For example, if you make the tenon 4", the 100mm jaws are too small at max extension (max size about 3.89"), and the 130mm jaws will not contract down to 4" (min size is about 4.25"). The same thing seems to be true for a tenon of about 3".

Now, I guess I could keep a table of the max and min sizes in the shop and only make tenons that are supported, but that seems like a very poor design of the chuck. I should be able to make a tenon of any size from the smallest supported by the smallest jaws, to the max size supported by the largest jaws - the support should be continuous across the jaws.

I'm PO'ed enough that I'm going to sell the SuperNova2 but I don't want to buy another brand that has the same problem. Any recommendations?

Or am I missing something?

Mike
 
I've got a Supernova 2 and a G3 and I've seen the same "sizing gaps" you mentioned on both of them. So far, it really hasn't been a problem, since my tenon dimensions are pretty flexible. When I find I'm at the "in between" size, I just make the tenon a bit smaller until it fits the next size down.

I'd say that for about 95% of what I've turned with a chuck, I've used either the 50mm standard jaws or the 45mm spigot jaws. I've got the 100mm jaws, but haven't really used them much. I tend to prefer smaller feet, so I usually start with a smallish tenon.

(Let me know if you decide to sell the SN2. I might be interested.)
 
Mike,

I've have the SN2 and a pretty complete set of jaws too. I found the same problem. The only time I've run into a problem with the gaps is turning Ed Davdison's acrylic blanks. The diameter of the blanks is such, that I can't grasp one with any of the SN2 jaws to drill the b/s blanks on the lathe. When you drill them on the d/p, it's easy to get them ever so slightly off centered. Woodcraft now carries a set of rubber jaws that can be turned to grasp what ever size you need. I haven't tried them yet.

If you put that SN2 up for sale, I might be interested also.
 
Thanks for the replies. Since I posted I've been doing some research on other chucks and it seems that all of them have similar gaps.

A problem I encountered is that I'd turn a tenon on the lid of a box (for example), then part off the top to turn the inside of the top. But when I try to mount it in the chuck (which until then was being used to hold the blank) it doesn't fit. I'm then in a pickle since I can't turn the tenon down (since I parted the top off). Just extremely irritating and not something I expected anyone would design.

If all the "name" chucks have the same problem, I'l have to live with it, but I certainly expected better. If I had many chucks, I could trial fit the chuck before I parted off the top but I only have one SN2.

Mike
 
I have a set of plywood scraps with the min/max dimensions cut out so I can make sure the tenons are the correct size. Easy to create and solves the issues you have been experiencing.:thumb:
 
Like Gari said; take some 1/4" plywood scraps could use 1/2" or 3/4" make a go no go board. IE; max and min. of each jaw size. I keep mine right next to the lathe to check my tenon size. I usually made mine a hair to large until I went with the plywood gauge.
 
Doesn't that stink! Drove me nuts when I first started.

But to tell you the truth, I hardly notice it any more. I just got used to how big I need to make a tenon.
 
Mike I believe you will find that problem with most all chucks. I bought a Vicmarc VM100 and found the $99 Griz chuck is the same thing. So for $99 I bought 3 of them. I put the Cole jaws on one, the shark jaws on one, the 4" jaws on one and the regular jaws on the VM 100. Most times I use the shark jaws which go from 1 5/8" to 3 1/8" or the regular jaws which go from 1 1/4" to 2 3/4". Which ever chuck I have on I use a calipers set for like 2 3/4" for the shark jaws or 2" for the regular jaws. Just something you live with.
 
Yep, that sucks, the only way around it I've found is to use a "go-no-go" template like others have mentioned.

I have found that the larger Titan chuck can be put to good use, as it has more range of movement.

One other thing, I was shown this at a demo, I'm not sure it if was Eli Avisera or Jean-Francois Escoulen who showed us, but you really do want your tenon size to be as close to the minimum sized the specific jaw set will hold, as the closer the jaws are to a perfect circle the stronger the hold will be on the tenon, and the less vibration you will get, thus, I use about a 2 1/4" tenon with the 50 mm jaw set on the G3 chuck I have, and if I'm working larger wood, then I switch to the Titan, and a different set of jaws, 3 1/4" tenon, Titan and the 75mm bowl jaws, 4" tenon, Titan and the 100mm bowl jaws, 5" tenon, Titan and the Titan power grip jaws.

My point is that just because the jaws will open to a max size, does not mean that you should use that sized tenon. I think you are further ahead by sizing your tenons to the jaw sets you have, not the other way around.

Just what works for me. :dunno:
 
Stu I forgot about that. I think it was Eli that said you want the jaws to where they are almost closed on the tenon to hold properly. By the way Stu I will see Eli at Richmond.
 
Mike,

I talked with a friend. He uses a set of gauges made like open ended wrenches. He made them from plywood and has the jaw size written on them. One end is the max limit....the other end is the minimum size. As long a tenon fits between the two...it's good to go.
 
Bernie, then you are in for a treat, Eli is one of the nicest guys I've yet to meet, and boy can that guy turn!

He has some ideas about tools and sharpening that are really fresh looks, that I very much enjoy.

If you actually get a chance to talk to him, and have a moment, please say "Hi" from me.

Cheers!
 
I'm going to try a set of those plastic jaws that Nova makes to see if I can grab the missing sizes. I'll let you know how it works. The plastic jaws are fairly low cost but I'm afraid the plastic will not grip well or wear out quickly. We'll see.

I need to do something or just give up on the piece I was working on. The "go/no go" tool that Ken mentioned sounds good for the future (keeping in mind to stay close to the min).

Thanks everyone for your comments and suggestions. And since all the other brands seem to have the same problem, I won't be selling the SN2 - but thanks for the offers!

Mike
 
Mike, if I'm understanding the problem, there might be a way to reverse the box top in a friction chuck, holding it in place with the tailstock long enough to reduce the size of the tenon a little so you can grab it. If you could post pics of the piece, someone here might have a bright idea.
 
mike, i bought two sets of the plastic jaws for supernova and use them. i turned two diameters in one set and a 1" dia. in the other. i use the small set for finials as the cuts are light and i can get right up to the jaws without fear of damaging the gouge or skew. also keep the finial on the chuck while staining black and so that set has black ink smudges...but so what? better than my fingers getting black.
 
Mike, if I'm understanding the problem, there might be a way to reverse the box top in a friction chuck, holding it in place with the tailstock long enough to reduce the size of the tenon a little so you can grab it. If you could post pics of the piece, someone here might have a bright idea.


I was just thinking the same thing.

I use the box base as a jam chuck to turn the top and lid. To clean up the bottom of the base I use a jam chuck.
 
Bernie, then you are in for a treat, Eli is one of the nicest guys I've yet to meet, and boy can that guy turn!

He has some ideas about tools and sharpening that are really fresh looks, that I very much enjoy.

If you actually get a chance to talk to him, and have a moment, please say "Hi" from me.

Cheers!


Will do Stu.
 
Just an update. I found that the Nova "step jaws" covers the hole at 3" pretty well (bought the jaws and tried them). The support for a 3" tenon is with the outermost steps so it's a lot like a regular set of jaws except the clamp area is not as deep as a regular set of jaws - but it's very usable.

I also bought a set of the plastic jaws and will shape them to cover the hole at 4". I'll let you know how that works after I have a chance to use it.

Maybe it's designed with those coverage holes so they can sell you more jaws.:)

Mike
 
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