4 Jaw chuck runout

Dave Black

Member
Messages
638
Location
Central PA
I just got one of these for my custom lathe I just built and noticed that there is quite a bit of runout on the jaws, the chuck body spins true but the jaws are obviously not true. I know that the jaws are only round at a certain opening and that is not what I'm talking about. If I chuck up a shaft it has very visible runout. Ill have to measure it but I just wanted to know what to expect from something like this and if I should return it to grizzly/amazon. Ill also have to get some pics of the new lathe.

http://grizzly.com/products/4-Jaw-Chuck-1-1-2-X-8-TPI/H7820
 
Is it assembled correctly? Each jaw has a number. There is a corresponding number on the chuck body.

The chuck came assembled and there is a roll pin in there chuck body to keep the jaws from coming out(like they would on a metal lathe scroll chuck). So yes it should be assembled correctly, if the jaws were in the wrong slot then there would be something like 0.300 of runout.
 
I'd send it back. That much runout would be unacceptable to me.

Can you post a link to the chuck in question?
 
Only some possibilities...
Even though it came assembled, with Nova they tell you to scroll with the jaws about 1/2 turn loose. The jaws should self align when scrolled in tight and then you give the jaw screws the final tightening. As far as the pin to keep the jaws from coming out, with Nova the pin is to keep the jaw slides from coming out. The jaws can still be installed to the jaw slides improperly (even from the factory).

Did the insert/adapter come pre installed? This can cause a lot of problems also.
I assume you are measuring the run out on the jaw and not the run out on the shaft itself.
 
I'm not an engineer or machinist, but sounds to me like it needs to go back. I don't have any personal experience with this chuck. For most of my work I use a Nova Super 2. The other chucks I use are "stick chucks" from Woodcraft by Woodriver. They are good, solid chucks that I use for my cole jaw setups. One is the 8" and the other is the 16". I tried one from another source and it was a piece of junk. I am just smart enough to know if it is working right or not they do. I'd tell Grizzly to send you a shipping label and send it back.
 
Inserting jaws properly can be a bear. Double check the numbers to see if they were put in the right slots by the factory. You won't hurt anything taking them out and reinserting then trying again. I have a three jaw that lines up properly when I insert the jaws only about once in twenty tries.:bang: (BTW, a three-jaw is no way designed for using with wood.) If you can't get it right, do consider sending back to Grizzly.
 
I talked to grizzly support. They said it was too much runout. They didn't have a runout spec but said that it should around .002". So it's going back to Amazon. Hopefully the next one will be good. I have heard good things about these chucks.
 
Sorry, but what do you mean by 'runout?' :huh:

Runout is a slight error in a rotating tool, machine component, etc., such as being off-center or not exactly round.

Dave, if the chuck is like any other wood lathe chuck I've seen, Mike Mills is correct about the jaws being removable. The pin you're seeing is to keep the jaw slides (the parts the jaws attach to) from coming off the chuck when the jaws are fully opened.
 
Runout is a slight error in a rotating tool, machine component, etc., such as being off-center or not exactly round.

Dave, if the chuck is like any other wood lathe chuck I've seen, Mike Mills is correct about the jaws being removable. The pin you're seeing is to keep the jaw slides (the parts the jaws attach to) from coming off the chuck when the jaws are fully opened.

Yes I meant jaw slides. The dovetail jaws come off via Allen screws and have an alignment "ring" machined in the back of the jaws that mates with a groove in the jaw slides.
 
Yes I meant jaw slides. The dovetail jaws come off via Allen screws and have an alignment "ring" machined in the back of the jaws that mates with a groove in the jaw slides.

As Carol mentioned above, check to be sure the jaws are matched up with the right jaw slides. They will both be numbered, either with numerals or with one to four dots. You'll probably need to remove the jaws to see the numbers. Jaw #1 goes on slide #1, jaw #2 on slide #2, and so on.
 
Well I returned it, however a guess that amazon is no out of stock of these so a new one hasn't shipped yet and there is no estimated date. So I can order a new one from grizzly through amazon or just get a different chuck. I see a hurricane htc100 that will fit, its only about $10 more than the grizzly h7820 that I had returned. Or for a little more I can get the htc125 5" chuck, though that may be overkill? Just so you know I ended up making the spindle on my lathe 1-1/2 8 TPI even though 1-1/4 8 is more common. My main factors were the way I was putting a morse taper in the spindle (inserting a morse taper sleeve in a 1" bore) and I have a bunch of metal lathe chucks that I see myself using for things on this lathe ( I have used 2 metal lathe chucks on it already!) So recommendations?
If this change of topic warrants a new thread let me know.
 
I've not used the Hurricane chucks, but personally I think I'd go with either Teknatool (Nova) or Oneway for a chuck. That would assure the availability of a wide variety of jaws in the future. My choice for a 4" (or so) chuck would be the Supernova 2. By the time you buy a thread adapter it's comparably priced with the Hurricane: [URL]http://www.tools-plus.com/nova-lathes-23055.html?utm_medium=feed&utm_source=froogle&utm_term=NOV23055&gclid=CjwKEAiAzuK0BRCW4tiLpJT-8TISJADV8cw9po2kA6fOo3lG0l1meflpZHE5OopQtWu1fjOVoJuwhBoCzrzw_wcB[/URL] The jaws for the Supernova 2 will also fit the Teknatool G3 chuck, which is a bit smaller If I was going with a 5" class chuck, I'd be considering the Nova Titan.

Oops...scratch that. It doesn't look like Teknatool makes a 1 1/2" thread adapter for their chucks.
 
I have the Hurricane 100 and find it equal to or better than the Nova SN2 (and I have seven Novas).
Unless you are planning on something really really big I don't think you will need the Hurricane 125.
Even with Nova SN2's most of my turning is with their smaller G3s.
 
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