Chuck Test Question

[Richard Madison]

Seems like, beyond the availability of various jaw sets and inserts, smooth operation, and other details I have not thought of, the test of chuck quality is how well it centers and aligns the work. The cross section where the jaws grip the work should be concentric with the lathe spindle, and the combined face of the jaws should be flat and perpendicular to the spindle axis.

Given that a wood test piece might compress unequally in the jaws, a carefully machined steel or aluminum test piece might suffice for comparison. Said test piece might be about 6" long, 3" machined diameter, with a 3/8" deep, 2-1/4" diameter tenon on one end for test with 2" jaws. The shoulder from 3" to 2-1/4" would be flat and perp. to axis of the piece. One test would be to measure the radial run out next to the jaws and at increasing distance from the jaws.

It seems likely that manufacturers have a somewhat similar q/c test for their products, but have never seen any privately published data. Any takers? At the moment I have no reason to believe that a $250 chuck is any better than $99 chuck. What do you think?

[David Christopher]

not sure about all that mumbo jumbo but I have a woodcraft scroll chuck and a oneway stronghold and the difference is night and day... the cheeper one is not bad but the stronghold is awesome

[Jeff Nicol]

The higher end chucks that use the one handle scrolling method to tighten them are better than the ones you need two rods to tighten. I have a NovaII, a ONEWAY Stronghold and a psi BarracudaII. They all do the job but are all different sizes and the Nova has smooth dovetail jaws. The other two have serrated grips. The thing is that we are working with wood and it changes shape all the time so I think we don't need to get to precise with how things are gripped. I figure if I rough turn a bowl with a woodworm screw and turn a tenon on one end. When I swap it over and I tighten it in the chuck and see little or no wobble in the piece, it is good. I have never wondered if there was any misalignment in any of my chucks. I did switch jaws on the PSI chuck and did not tighten a screw all the way and I felt it right away. So a little maintenance should be all we need.

Just my opinion,

Jeff

[Gordon Seto]

The flaw I see in a privately done test is the test data may not be representative. I am not saying the $250 chuck is better or the $99 is equally good.
Some of the bargain products may have a loose specification. Testing result from 1 or 2 samples may not be good enough to represent the whole model. Some company may have a very tight QC, the buyer may not have to gamble whether they get a good one.
Our Club bought a dozen live centers from Grizzly, we could see one of them is obviously crocked. To their credit, Grizzly sent out a replacement immediately and they didn't even want the defective center back. The live centers are cheap; they just ship them out when the shipment comes in. They never inspect them. We knew what we are paying for, they are less than one tenth the price of a Oneway live center system.
One other factor Russ Fairfield has touched on is the steel. The steel used in some of the chucks is hardened which would last longer.
It is costly to do an unbiased comparison without funding.

[Bill Blasic]

I myself have all Nova chucks including three that use the tommy bars. They are set up with a 1" X 8 thread. I use the three with the tommy bars on my Jet1220 VS. They are fast and grip as good as the G3's, the SN2's and the Titan. I initially stayed away from the Tommy Bar chucks because of comments about how hard they are to use. I have since found out that like I said they are very fast to use and they grip as good as any. Plus the added bonus that all Nova Jaws fit all Nova chucks except for the Titan Power Grip Jaws which only fit the Titan. The notion that one gets what they pay for is a well conceived idea. I will not tell you that the Nova Chucks are better than anything else just that they are what I started with and what I have chosen to stick with. If you buy a chuck and it works for you then that is what it is all about, if your having problems then maybe you should search out answers to what may be a better product. But again I would stress that "You get what you pay for!" is not a bad notion to shop with.

[Richard Madison]

David,
Would be interested to know in what way(s) is one of your chucks so much better than the other one? As Jeff said, if it grips the wood and causes it to rotate when the lathe is turned on (and centers reasonably well), what else is there?

[David Christopher]

Richard, both chucks do the job well, I normally use glue blocks for turning bowls ( dont know if this is the right way or not ) and the stronghold chuck seems to hold large out of round blanks better. for smaller or more balanced work the woodcraft chuck works just as well

[Richard Madison]

Thanks David. That's the kind of info I was looking for. Also frequently use glue blocks for bowls and other stuff. In turning there are often several "right" ways to do stuff. What works well for anyone is the right way for that person.