Once again, late to a thread.
Things to look into when considering a chuck
- Mechanism for tightening and loosening the jaws
TWO tomy bars means there's no hand to hold the part being chucked while the jaws are snugged to it and then tightened. If you have a spindle lock on your lathe then you only need to use one tomy bar and have another to hold the piece in which case this isn't an issue.
A jacobs chuck key (either a short one like used on a drill press or on the end of a long T-handle) permits one hand tightening and loosening of the jaws - without the need for a spindle lock. BUT - and there always seems to be a "but" - this type of key only works when the long axis of the key goes in square to the long axis of the chuck - on a jacobs chuck or a lathe chuck. There are times - on some forms - where that isn't possible. THAT is a limiting factor for chuck keys.
A normal straight T-handled allen wrench mechanism has the same problem as the T-handled chuck key. However, a "ball end" allen wrench lets you tighten the jaws with the wrench angled back some towards the back of the chuck. This capability may not ever be used, but having it and not needing it is better than needing it and not having it.
- Lathes don't all have the same spindle size or threading. A chuck that has spindle adapters available to fit it and adapt to various spindle diameters and threads will allow you to buy just one adapter and keep using your chuck on any lathe you may get later.
- Jaw Sets - How many and what gripping size ranges are available.
If you really want to bang your head on the wall, turn a nice form with a tenon on the end to hold it in your chuck - and then find that none of your jaw sets will hold it for hollowing. Ideally, having sets that cover the full range, min to max - with NO GAPS - is REALLY nice to have.
- Jaw Sets - how easy are they to change?
On the "borrowed from a metal lathe" chuck you have to scroll one set of jaws off then scroll another set on - and starting from the right location and in the right order. Make a mistake on either and the jaws either won't close on center or won't close at all. THAT is a real PITA
On the "designed specifically for a wood lathe" chuck, the jaws attach to the chuck with allen head screws - one or two screws depending on the type of jaw. Makes changing jaws a bit easier, faster and a little more idiot proof (the latter very important if you sometimes fall into Idiot Mode - ok, so I'm the only one who does dumb things -occassionaly)
- Jaw Sets - can you put them on anywhere or does Jaw #1 HAVE TO GO ON IN POSITION #1 ON THE CHUCK
Don't know about other chucks, but the SuperNova2 jaws are each numbered and have to be put on their right location. Note that at least one set of jaws I have have simple center punch marks to indicate the jaw number - one dot for #1, two dots for #2 and so on. THAT is a minor PITA. All the other jaw sets have their number stamped in the underside of the jaw.
- Jaw Sets - are most if not all the jaws you have for this chuck fit the other chucks the manufacturer/company makes?
You WILL get additional jaw sets over time and may end up with ALL the jaw sets available for your first chuck. While the price of the original chuck seems like the big ticket item, the price of all the additional jaw sets will equal or exceed the initial chuck price.
- Does ANYTHING protrude from the outside of the chuck? If so, anything that does WILL wack you on the knuckles - at least once.
- Are there ANY sharp edges or sharp corners ANYWHERE that can (and will) make contact with any part of your body - while installing, removing or using the chuck?
- Are the interior moving parts protected from dust, dirt, oils, waxes, blood, insects, pitch, sap, . . . A chuck that works smooth and flawless when right out of the box - but binds and chunks in use is nice to look at but a PITA to use over time.
- Does the chuck have built in Indexing?
Being able to index the chuck, even if you don't think you need that capability now, will give you the option later.
Some chucks have indexing holes or slots on the rear outside of the chuck and some have them on the back face of the chuck. Being able to get to them from the top makes it easier to add an indexing pin to your lathe than adding one from behind the chuck.
- The quality of the steel in the moving parts and the precision of their machining.
Good steel holds up - crappy steel doesn't. If the mechanism is machined steel rather than cast iron and then machined, it will hold up, trouble free for year and years. Machined cast iron won't.
Some of these things you can see, some you can't. It's the reputation of the company that tell you something about parts you can't see. If you've never heard of the maker, or the outfit that carries it won't stand behind the chuck you're screwed if anything is wrong or goes wrong with the chuck.
Just what you needed right - more decisons to make. Sorry - but knowledge is power.
charlie b
Disclosure: I have two SN2 chucks and ALL the jaw sets for that chuck. I have no financial connection to the maker, wholesaler or retailer of the SuperNova2 and paid the store price for the chucks and jaw sets. I use them on a JET mini/midi and haven't turned anything bigger than 9" in diameter nor taller than about 6 inches.