New Turner / SuperNova 2

[Wells Jacobson]

I am early on the turning learning curve and have yet to turn something that comes out the planned size and shape. I love this forum and hope someday I can contribute.
Now and then I read something that makes me really question the safety of what I am doing. I use a SuperNova 2 chuck that was given to me with the 50mm jaws. After starting with small boxes I have recently roughed out a few bowls about 10" in diameter. One of the recent threads took me to the tecnatool website and I downloaded and read the chuck manual (better late than never). It says: "With the standard set of 50mm jaws a maximum size wood blank of 100mm (4 inches) diameter (NOT spigot size) by 150mm (6 inches) length can be turned." I have been using a tenon (spigot) and would like to know if the 50mm jaws are unsafe for what I am doing or if a different set of jaws would be more secure.
Many thanks,
Jake

[Al Wasser]

If you are going to be doing 10" bowls consistently I would consider getting a larger set of jaws. Having said that I have turned several 10" bowls with the 2" jaws. If you are prone to getting catches a larger set will give you more holding power. Go slow and keep your cuts light and the 2" will work fine

[Gary Max]

Sounds like a good reason to buy more tools-----I do not use the 50 mm jaws that come with the chuck---heck if they would offer just the body at a reduced price I would be happy.

[Harry Robinette]

Wells
I've been using a super Nova for allot of years and I turn up to 14" to 15" bowls all the time with the 50mm jaws in the contraction mode.( clamping down on a spigot)
Haven't had a problem yet. BUT YOU MUST TAKE CAUTION iT'S NOT JUST THE CHUCK. Allot of factors come into play, SPEED,WOOD,TENON,TOOL CONTROL,EXPERIENCE AND ALLOT OF OTHER THINGS. As always if you have a bad felling DON"T DO IT. And ALWAYS WATCH YOUR SPEED.

[Richard Jones]

I have used an SN2 with the 50mm jaws for bowls up to 15" for a # of years, but recently got a set of 4" jaws and I think I will breathe a bit easier on some of the heavier blanks. FYI, the 75mm jaws that I got several years ago still only will grip about a 2" tenon, but will do a 3" recess. Not sure why the didn't indicate this at the time, would have saved me some money...........

Max, CSUSA does sell the SN2 without jaws, if you're interested.

Rich

[Bill Blasic]

I have no problem turning 15" pieces with the 2" jaws and the SN2 for years. Solid wood and correctly cut tenon and I'm good to go.
Bill

[John Keeton]

Just a couple of thoughts, Wells. Make sure you leave the tailstock up for as long as possible for support, and note that the manual speaks of an extension of 6" from the chuck. That is where the leverage factor comes in. Making a cut 6" out from the chuck places many times more force on the chuck/tenon connection than does making a cut up close. Similarly, cutting heavy on the far outside edge of a 15" blank does the same - thus the tailstock.

I wouldn't hesitate to use the 50mm jaws and do all the time, but as Harry said, there are a lot of other factors that come in to play.

[David E Keller]

I've done several bowls over 12" with 50mm jaws and no troubles to speak of... Larger jaws and a larger diameter tenon would be safer though.

[Scott Hackler]

I use my 50mm jaws 99% of the time. I have a 75mm set and did use them on two 15" bowls in expansion mode, just because of the shear weight of a 15" dia x 9" tall blank. One of the other reasons I prefer the 50mm set is the face plate ring I bought that fits these jaws!

Good solid wood, a properly cut tenon and the correct technique will result in no problems.

[Wells Jacobson]

Thanks for the many helpful comments. I feel a bit safer already --but do take the cautions to heart.
Wells

[Wells Jacobson]

Scott. I'm not sure i'm even responding appropriately by hitting the reply button. I don't understand your second sentence. Why would you want to put a face plate in your chuck?
Thanks,
Jake

[Scott Hackler]

Jake, I am talking about a faceplate "ring" designed for the 50mm SN2 jaws. It allows me to leave the chuck on the headstock and mount a goofy chunk of wood with the faceplate ring and some beefy screws, until I get a tenon cut on the opposite side. Most of the time I will round the entire blank while the face plate ring is installed and the tailstock is being used for support, before flipping the blank around and clamping onto the tenon.

[Wells Jacobson]

Thanks for the clarification, Scott. Now I see what you are doing. At my stage I'll use a standard faceplate as technical ability is still far and away my rate limiting step. I am enjoying the learning curve and am always happily amazed at the camaraderie and helpfulness of an internet forum. It elevates the spirit.
Jake

[Richard A. Rivera, M.D.]

Sounds like a good reason to buy more tools-----I do not use the 50 mm jaws that come with the chuck---heck if they would offer just the body at a reduced price I would be happy.

Gary, I have recently spoke to the people at Nova Support and they now have a "refurbished" store at ... novatoolsusa.com ... you can buy a refurbished SN2, no jaws with 1 year warrenty for less than a new one.
They also said by eary winter they will bring back the 5" Titan chuck

[neil mackay]

It says: "With the standard set of 50mm jaws a maximum size wood blank of 100mm (4 inches) diameter (NOT spigot size) by 150mm (6 inches) length can be turned." I have been using a tenon (spigot) and would like to know if the 50mm jaws are unsafe for what I am doing or if a different set of jaws would be more secure.


Jake, I have 5 SN2 chucks and I have found that they are darn good chucks with capabilities far greater than stated by Teknatool.

Teknatool are very conservative with thier recommendations and direction in thier respective brochures.

However, having said that,if your starting out,play it safe and go for bigger jaws etc until you build esperience and capability.

[Michael Mills]

From page 9 of their manual - EXPLANATION OF TWO OF THE MORE COMMON CHUCKING TECHNIQUES USED IN THIS MANUAL
http://www.teknatool.com/products/chuck_accessories/General/downloads/Accessory%20Jaw%20Manual_Nov07.pdf

SPIGOT OPERATION
Contraction of the jaws around a wooden spigot for grip. Mainly used for box,
goblet and vase turning, that is, endgrain items with a fair degree of overhang.
Generally tailstock support is minimal or cannot be used because of the need to
hollow out the inside. This method seems to be preferred by many bowl turners
over the internal dovetail recess as the foot can later be re-shaped or removed, if
desired, to make a smooth outside bottom of the bowl.

So, in my interpretation of Teknatool’s statement, a “spigot” is always endgrain, AND unsupported at the tailstock when they are talking about capacity. Certainly I do not think they mean that you can not use them to turn a softball bat (supported at one end) or turn a larger diameter with tailstock support. They also give much different dimensions for bowls using “expanding dovetail” method for the same jaws.

It seems to me that in woodturning this method is either spigot or tenon. However, I have never seen a flat worker make a tenon (as in mortise & tenon) cross grain.