Supernova Chuck on Jet Mini?

David,

I use both a Nova Compac chuck and a Super Nova on my Jet Mini as I have for almost 2 years with no problems to date. You will notice a bit of a "flywheel effect" because of the heavier weight of the Super Nova, but it has caused me no problems.

I have read various other posts about the added stresses on the headstock bearings caused by larger and heavier chucks. I don't quite buy their arguments. The added stresses do not result from the rotation of the chuck or the forces resulting from tightening the chuck.

The real cause of added stresses on headstock bearings is because with a bigger and better chuck, you may tend to turn larger and heavier blanks, but you are still limited by the capacity of the Jet Mini (10" D X 14" L). The real stresses are caused by turning these larger blanks and using larger tools which, in turn, generate more leverage against the headstock bearings. Another factor is that larger chucks tend to "hang" further from the headstock, which also causes some added stresses.

None of this would stop me from using a Super Nova chuck on a Jet Mini Lathe. Besides, if you wear out the bearings, just replace them.

Barry

I've heard conflicting reports on whether or not a Supernova chuck is too heavy for a Jet Mini's bushings/bearings. Is the difference in weight really all that much?

Relatedly, doesn't the method of tightening the Nova put quite a bit of weight on the bearings/bushings in the first place -so that the Supernova may actually be better b/c you never have to tighten with force downward on the headstock?

Thanks in advance, Dave

Barry N. Turner wrote: I use both a Nova Compac chuck and a Super Nova on my Jet Mini as I have for almost 2 years with no problems to date(clip) ^^^^^^^^^^^ Barry has it right. This comes up from time to time in this group, and, after considerable discussion , the answer settles out as Barry said. Not to worry. It's a concern felt by some turners, particularly those without engineering background, and those who have not thought it through. The size and weight of the wood, and the forces resulting from the turning process have much more to do with the bearing loads that the slight additional size and weight of the chuck.

Using the tailstock as long as possible when making your pieces probably preserves your bearings better than a lesser weight chuck. What would bother me is the loss of capacity from a longer chuck. Regular Novas work in a bit less space, and as you are tightening the bars against each other, should make no difference with the bearings, even if they were so weak you could pull them out of round.

Own two regulars and a Super, and the only way I chose which to use in my shop is by which jaws are currently attached.

Many of us come by large & heavy old chucks and other fitments, so this discussion by our engineers and others with experience should be a helpful guide. Leo's use of 'slight' piques my interest. Does a heavy but balanced and empty chuck put damaging stress on lathe bearings? If so, are there any guides as to how heavy the chucks, spindles and bearings need to be to be compatible? FWIW, once I was warned by an Atlas Co. employee not to adapt their 3 jaw chuck made for their 12 in. lathe to their 6" lathe as it would ruin the bearings. Arch

Fortiter,

Since I turned after lunch, I checked. The difference in length between the Nova and the Super is 3/8 of an inch in the prebored version. Not enough to worry about. Super's nice.

You can talk to your Physics types about asymmetrical loads, but I wouldn't worry.

Thanks to everyone for the useful input.

I thought the Woodcraft employee took the more expensive option off the table, but now I'm back to weighing the two. Most turners agree that the $70 more is well spent on the supernova, so I'm leaning that way. I'd love to hear from any fans of the nova over the supernova.

Thanks again, Dave

David, Before you lay down your greenbacks at Woodcraft, take a mosey over to

This Canadian dealer has great prices and good customer service, to boot.

Just a satisfied customer...

-- Chuck *#:^) chaz3913(AT)yahoo(DOT)com Anti-spam sig: please remove "NO SPAM" from e-mail address to reply. <

September 11, 2001 - Never Forget

Yeah, I hate to say it, but I went to Woodcraft to handle and see exactly what I'm going to get when I finally do pull the trigger and buy one on-line. : ) Woodcraft is a great place, but when the savings start going over $15-20, I usually do buy online.

For what it's worth, there's a fellow on ebay who's selling novas for $99 and supernovas for $159, and those include some jaws and your size of thread. Pretty excellent deal.

Thanks again, Dave

I bought my Super Nova from KMS Tools with 4 sets of jaws, for about the same I would have paid elsewhere for the chuck and standard jaws. Nice folks, too.

Barry