Supernova 2

[Derek Cohen]

I have a Supernova 2, purchased 10 years ago, then for a Jet mini. I never did use it for small bowls (turned a lot of spindles, however).


Now I have a Nova Saturn DVR and want to try my hand at bowls. It seems that I could do with a few accessories for the Supernova 2. Suggestions?


Also, I had a turning friend over yesterday, and he pointed out the the jaw of the Supernova is not dovetailed, but instead has a ring along the lip. Can anyone comment on this? I realise that a dovetail will hold the work piece more securely, but do I need to replace the jaw with a dovetailed one, that is, how much am I missing?


Regards from Perth


Derek

[John K Jordan]

Derek,

That's curious about the dovetail. I have 19 Teknatool chucks (Supernova, Supernova2, G3, and Titan - I'd rather buy another chuck than change the jaws )
I think I have most of the jaws they sell and without going down to the shop to check, I think most of them are dovetailed inside and out for both expansion and contraction. (The exceptions are the insides of the spigot and some of the very small jaws.) [edit: OK, I walked back down to the shop to check.] I have no idea what the guy means about the "ring along the lip" unless he did not look carefully at the small internal dovetail in the 50mm jaws.

I assume you have the 50mm (2") jaws that came with the chuck. The jaws are dovetailed inside and out. The outside is angled all the way to the base of the jaws. The inside is angled less that 1/8" but that is plenty for relatively small bowls and platters and larger ones with some care. I usually use a recess and even though that dovetail is long I don't make a deep recess - even 1/16" holds well for things made from dry 8/4 stock 8-10" in diameter. (If you are not used to using recesses or tenons for bowls and such just be certain the recess or tenon is not so deep/long that the wood can touch the base of the jaws - there are specs in the manual)

You can look at pictures of the jaws here and see the dovetails:
https://www.teknatool.com/product-ca...w-accessories/

The manuals for the individual chucks and the entire line of jaws are available as PDF files near the bottom of the appropriate pages.

The specific jaws you get for bowls depends somewhat on the size of the bowl and the holding method (recess, tenon). The jaw manual has tables for recommended sizes for various jaws. They are a good starting place but not necessarily the law.

The least useful jaws are the step jaws. Don't waste your money (my opinion).

I don't know what other kinds of accessories you mean. I do highly recommend always using their wrench to remove the chuck. I've seen chuck key sockets damaged by using the key to break the chuck loose. The wrench fits all the inserts. I bought several years ago but I don't see them on Teknatool's web site right now. I recently bought another through Amazon and while it works, the quality and finish are lower.

BTW, for no extra charge: a general tip for tightening chuck jaws, for both dry and wet wood, both face, endgrain, and spindle turning - instead of cranking down on the chuck key to tighten I think it will hold better and put less stress on the wood if you tighten moderately in one socket hole, then move to the other and tighten the same amount, then repeat several times in both holes. After a few times you can easily feel the jaws snugging tightly on the piece. If you tighten in just one socket you can feel how loose the jaws still are when you move to the second. This is due to backlash in the gears, clearance left in normal machining. I bought several used chucks from one gentleman who must have had Hulk arms or used a cheater bar - the metal of the chuck body was deformed from too much force! (I fixed them) He had probably experienced chucks loosening.

I heard one demonstrator say "tighten in all six sockets"! Without this tightening method the piece can actually loosen a bit from the chuck components settling after turning just a little, in both dry and wet wood. A recent well-known symposium demonstrator mentioned how quickly a green blank can loosen from drying - I think he never learned this tightening method because I watched him always tighten in just one socket.

I learned this years ago from a veterinarian who was taught the multi method in school, not for wood but for surgical equipment.

JKJ

I have a Supernova 2, purchased 10 years ago, then for a Jet mini. I never did use it for small bowls (turned a lot of spindles, however).

Now I have a Nova Saturn DVR and want to try my hand at bowls. It seems that I could do with a few accessories for the Supernova 2. Suggestions?

Also, I had a turning friend over yesterday, and he pointed out the the jaw of the Supernova is not dovetailed, but instead has a ring along the lip. Can anyone comment on this? I realise that a dovetail will hold the work piece more securely, but do I need to replace the jaw with a dovetailed one, that is, how much am I missing?

[Tom Wilson66]

According to the Supernova2 manual, the proper way to mount the piece in the chuck is to use a dovetail in a recess and a straight sided tenon. The "ring" at the top of the jaws (this is not a dovetail) on the inside will bite into the wood at the base of the tenon for the proper hold, so no recess is needed at the base of the tenon to get the strongest hold.

[Mike Peace]

I have the full range of Teknatool chucks and really like their 50mm jaws that come with the chucks because it is easier to make a parallel tenon than a dovetail. They hold blanks very securely. Record Power chucks have the same standard jaws and refer to the miniature dovetail tooth as a "hawk beak" design. they use the same design on their 35 mm standard jaws. I bought a 35mm Sorby set of jaws for smaller work that has a true interior and exterior dovetail before I knew about the Record Power 35mm jaws which I would have preferred. Sorby Patriot, Record Power and Teknatool have identical jaw fixings and are interchangeable.

[John K Jordan]

According to the Supernova2 manual, the proper way to mount the piece in the chuck is to use a dovetail in a recess and a straight sided tenon. The "ring" at the top of the jaws (this is not a dovetail) on the inside will bite into the wood at the base of the tenon for the proper hold, so no recess is needed at the base of the tenon to get the strongest hold.

I call the inside a dovetailed since it is angled like a dovetail, although smaller. I do use a mostly straight tenon but cut a small dovetail if the wood is hard. As you say, softer woods need nothing with a tenon, since the small dovetail bites nicely into the wood.

Although a recess is best dovetailed with the 50mm jaws, they do hold well even in a straight-sided recess drilled with a 2-1/16" or 2-1/8" Forstner bit since the expanding dovetail also cuts into the wood a bit. But if the piece is large, the wood very hard, the recess shallow, or the wood green I cut a proper dovetail in the recess.

JKJ

[John K Jordan]

....I bought a 35mm Sorby set of jaws for smaller work that has a true interior and exterior dovetail before I knew about the Record Power 35mm jaws which I would have preferred.

Doesn't Woodcraft have all the Record Power jaws on sale now? I'd like to try some.

[Bill Blasic]

I see that John has caught up to my 19 Nova chucks, now if he gets 17 of the other brands he will surpass me. I agree with him about the 2" jaws as it has a small dovetail on the inside of the jaws. Pay no attention to Teknatool's description of using straight sided tenons. I make my tenons for the 2" jaws no more than 3/16 long and mostly 1/8" is sufficient to hold the piece securely. I have asked Teknatool if they make the Record stuff because it is exactly the same stuff, it looks like Nova equipment.

[John K Jordan]

I see that John has caught up to my 19 Nova chucks, now if he gets 17 of the other brands he will surpass me. ...

Ok, I didn't know it was a contest but you win! But how many dedicated screw chucks do you keep, e.g., Glaser?

People have asked me why I have so many chucks. Besides not changing jaws, I have multiple chucks with the same jaws, for example I often have work in progress in chucks I don't want to remove until finished. And with a student or two they also may have an unfinished piece waiting till the next visit. Some things are a little easier with two. And on rare occasions I may loan to a one to a friend for a demo (OK, when am I going to get that one back from Mr. B.?!) I buy them when I see them at a good sale price and used when I find them. Some people, of course, think only Vicmark, Oneway, etc is worth having. I'm quite satisfied with the Technatool.

JKJ

[Roland Martin]

I only have 5 Supernovas, feeling a bit deprived, haha. I’ve never bought in to Technatool’s theory of straight tenons with their jaws. When tightening jaws that have dovetails against a straight tenon, the small diameter of the dovetail that is against the bowl bottom crushes the wood fibers where holding power is most needed before the rest of the jaw makes proper contact. The same happens with a straight recess. I’ve always slightly dovetailed my tenons and recesses for this reason. Also, as John pointed out, it is very important to tighten the jaws back and forth as he explained. Just my opinions!

[John K Jordan]

I should point out at the Teknatool/Nova jaws I have that are advertised as "bowl" jaws all have what some might call real dovetails on the inside, as well as the outside. They are not always as long as the outside - the inside dovetail on the 75mm jaws is about 1/4" compared to the 3/8 outside dovetail: https://www.teknatool.com/product/no...ssory-jaw-set/

Also, I found this diagram somewhere (forgot the source), showing the improper and proper way to cut the dovetail for a recess. Since it is unlikely we can cut a perfect angle, it is better to err on the side of putting the outward force tight against the bottom buried deeper in the wood instead of at the weaker surface.

chuck-recess.jpg

I think it is important for both registration and strength to cut a smooth band at the very bottom of the recess for the face of the jaws to press against. One pro pointed out that it is better here to err on the side of angling the band slightly concave towards the middle so the outside circumference of the jaws is able to seat nicely in the very corner. The other way can leave the jaw faces bearing at the inside circumference. Hard to explain in words - I really need to make a drawing. I like to press in and rotate the wood slightly while tightening the chuck to make sure it is well seated. Chris Ramsey, a cowboy hat turner, encouraged us to be meticulous in cleaning any sawdust, fibers, or whatever from both the wood and the jaws before mounting, especially when turning that big blank around to do the inside.

JKJ

[Hal Taylor]

If one looks at the 50mm jaw end on one can see the outside is dovetailed while the inside is straight, (not dovetailed) with a small “beak”. I make my tenons straight with a very small cut for the beak. Never have a problem with blanks coming off. Of course, one has to insure there is a 90 degree angle between tenon and base.

[Robert Hayward]

I do highly recommend always using their wrench to remove the chuck. I've seen chuck key sockets damaged by using the key to break the chuck loose. The wrench fits all the inserts. I bought several years ago but I don't see them on Teknatool's web site right now. I recently bought another through Amazon and while it works, the quality and finish are lower. JKJ

I use a 1 1/2" service wrench to remove a Teknatool chuck. The one pictured was bought from one of the tool trucks that sell to the techs at mechanic shops for $10.00 several years ago. The metric one is from a Harbor Freight set of service wrenches. I use a 29mm and the pictured 32mm to remove spindles from a Grizzly oscillating spindle sander. HF also sells an SAE set of service wrenches that has a 1 1/2" size in the set.

Service wrenches (Medium).jpg

[John K Jordan]

I like the looks of that wrench. It's usually hard to find a wrench for that size of nut that doesn't have a huge handle!

I don't have a closeup photo of the wrenches I use but one is hanging behind the lathe here. It's made of a flat piece of sheet steel maybe 1/8" thick or so; making one wouldn't be too hard. I've yet to understand what the small spanner on the lower end is for...

lathe_toolrests_IMG_5751.jpg

Some people say to remove a stubborn chuck just open the jaws and clamp a stick or rod or something between them and use it as a lever. This wouldn't be useful if you wanted to take the chuck off the lathe but leave the piece in the chuck! (I do that a lot since I do most of my smoothing and sanding off the lathe.) Also, I wonder about applying impact forces to the jaws but maybe that's not a problem.

JKJ

[Bill Blasic]

Ok, I didn't know it was a contest but you win! But how many dedicated screw chucks do you keep, e.g., Glaser?

People have asked me why I have so many chucks. Besides not changing jaws, I have multiple chucks with the same jaws, for example I often have work in progress in chucks I don't want to remove until finished. And with a student or two they also may have an unfinished piece waiting till the next visit. Some things are a little easier with two. And on rare occasions I may loan to a one to a friend for a demo (OK, when am I going to get that one back from Mr. B.?!) I buy them when I see them at a good sale price and used when I find them. Some people, of course, think only Vicmark, Oneway, etc is worth having. I'm quite satisfied with the Technatool.

JKJ

I have only one screw chuck but have never used it. I use the screw that comes with the Nova chuck and I consider it the best of all the screws that come with the chucks. I always hear the pros saying the Oneway screw is the best but I have two Oneway chucks and both screws snapped, never snapped a Nova screw. Most times I have to take the piece out of the chuck and use water pumps to get the screw out of the wood as they grip so well. I have Oneway, Vicmarc, Axminster and Bulldog chucks besides my Novas. I myself find them all on the same footing with none being better than the other and use them all depending on jaw configuration. I like John do not like changing jaws and I have a variety of lathes and have them all set up for various projects. Also all the lathes are cast iron as I like cast iron having run mainly vertical boring mills for 40 years of my working life.

[John K Jordan]

I used to use the Nova screw but after I got the Glaser I haven't touched the Nova screws since. I like the Glaser so much that when Jerry was gone and you couldn't buy them anymore I almost wanted to keep mine in a safe since I'd hate to be without it! Fortunately, I recently found out Alan Lacer is selling them again so I was finally able to get a spare. Yea!

Besides the 3-way support flexibility I really like the machined thread on the screw - threads on and off easily, grips like a demon latched onto a wayward soul. If you ever run out of the woodworm screws (unlikely!!) I'll send you some. Ha!

glaser_screw_chuck.jpg glaser_screw_chuck_2.jpg

Glaser Hitech started manufacturing them after Jerry passed on but for some reason they never had any to sell! Lacer got some stock and fortunately had 1-1/4"x8 on hand. I suspect these would be more popular if they were actually widely available! They are expensive, though.
http://stores.alanswoodturningstore....-screw-chucks/

JKJ

I have only one screw chuck but have never used it. I use the screw that comes with the Nova chuck and I consider it the best of all the screws that come with the chucks. I always hear the pros saying the Oneway screw is the best but I have two Oneway chucks and both screws snapped, never snapped a Nova screw. Most times I have to take the piece out of the chuck and use water pumps to get the screw out of the wood as they grip so well. ...