Need a new lathe chuck

Firstram

Registered
Registered
Joined
May 26, 2018
Messages
1,457
I have a 1340 belt drive Jet lathe. I would like to step up to a larger, higher quality machine but since I'm a traveling shop that's not really practical. The 3 jaw chuck that came with the lathe is terrible and it's time to upgrade. Tell me why I shouldn't step up to a Gator 8" 6 jaw. I only want one scroll chuck and I will give the current 3 jaw to someone I don't like if I buy this.

https://www.ajaxtoolsupply.com/8galach6jawt.html

I really only do one off stuff thats not high precision but often in sets of 10 or 20. I machine a lot of Delrin and Nylon as well as thin mechanical tubing. I find the the 6" is just too small way too often and don't want to swap to the 8" 4 jaw for a quickie. I learned on a 4 jaw and can quickly dial a part in but, most of the time it doesn't matter. A larger set tru would help me quickly do second operations on low tech parts.

Tell me why I shouldn't buy a 6 jaw as my primary scroll chuck!
 
If you are mostly using easy-to-machine materials, a 6-jaw will be adequate. Not one with thin jaws, but one with substantial, 2-piece jaws. Notice that the contact surface each jaw is less than that of a 3-jaw chuck. You can still use only 3 jaws, but remember the limited contact area means more chance of slippage and the workpiece escaping through the larger gap between jaw contact surfaces.

I have both 6-jaw and 3-jaw Buck 6" chucks on an Atlas 12x36. I tend to use the 3-jaw most. I agree that there is little reason to have a regular 3-jaw chuck if you have a set-tru.

An 8" 6-jaw is pretty heavy. It also has less clearance over the carriage wings. If these are not issues for you, I see no reason not to go for it.
 
Wouldn't a 6 jaw, 2x as many but narrower contact points, grip plastics better?
 
In general 6J do not have the holding power of a 3J or 4J, are more prone to jamming with swarf, and a 8" is a bit heavy. I do a lot of repeat in/out and multiple parts, I have a 6.3" PBA 3J scroll Setrite which works well, they also have a 6 jaw version, the 6" versions have a 1.8" through hole, the 8" have a 2.25" hole. But the issue with plastics is they will easily deform with a 3J and can twist out between the jaws. I tend to use a Bison combination 4J chuck in an 8", it offers both a scroll with independent jaws, the scroll will repeat to ~0.001"and for higher accuracy you can tweak the jaws. The jaws are reversible and will hold stock down to about 1/4", I find it is very accurate and for the most part easy and quick to use. Downside is it is quite heavy and cleaning can be a bit more cumbersome.

Gator gets mixed reviews on their chucks, they are direct copies of the Bison, and you can save a few dollars on back plates by using the Gator ones on Bison/TMX chucks. I have heard of qualty/finish issues on the Gators, and when I spoke to Ajax Ind. a few years ago they felt the Bison was a better chuck. Bison and TMX are comparable, depends on the chuck type. Ajax Industries and Small Tools are the common chuck vendors I recommend, and have purchased from both. Sometimes you might find a deal elsewhere. Inventory may also be an issue, although the chucks are often drop shipped directly from the manufacture's warehouse.

If you have you heart set on a 6J, at that price level I would either go up to a Bison/TMX chcuk or alternatively Shar's sells a 6J set-ture style scroll chuck that is 1/2 the price and a few people that have purchased them have been satisfied with the fit/finish/function. Price of chucks have skyrocketed, so tough to swallow the pricing.

 
One big advantage of 6J is the ability to grip thin materials without crushing/deforming. But often you can do workarounds like making
a split collar to hold the workpiece in your 3J if you don't have a 6J
-M
 
I machine a lot of Delrin and Nylon as well as thin mechanical tubing.
Jacobs flex collet chuck would be great for this type of work up to 2 inches possibly . :encourage:
 
I tend to use a Bison combination 4J chuck in an 8", it offers both a scroll with independent jaws, the scroll will repeat to ~0.001"and for higher accuracy you can tweak the jaws. The jaws are reversible and will hold stock down to about 1/4", I find it is very accurate and for the most part easy and quick to use. Downside is it is quite heavy and cleaning can be a bit more cumbersome.


I just spent as much for a chuck as I did on my lathe! The 8" Bison combo chuck won out and I doubt they will get any cheaper in the future. Dialing it in should be faster than a set tru and give more consistent pressure than a conventional 4 jaw once dialed in. It is heavy for sure and if it's too much for my 1340 I'll just buy a bigger lathe! The TL's have been calling my name...

Now I need to replace my terrible 6" 3 jaw. I think I'll give this Precision Matthews a try.
 
I just spent as much for a chuck as I did on my lathe! The 8" Bison combo chuck won out and I doubt they will get any cheaper in the future. Dialing it in should be faster than a set tru and give more consistent pressure than a conventional 4 jaw once dialed in. It is heavy for sure and if it's too much for my 1340 I'll just buy a bigger lathe! The TL's have been calling my name...

Now I need to replace my terrible 6" 3 jaw. I think I'll give this Precision Matthews a try.
Not everyone has unlimited financial availability.
 
Not everyone has unlimited financial availability.
I don't have unlimited funds by any stretch. I am still working and I have worked my way into a position where the tools I own and my ability to use them pay for themselves. The money left over after I pay for upkeep on my trailer, storage lot fees, commercial insurance, sales tax and income tax, I save. At this point in my life I enjoy good shoes, expensive socks and being able to buy a few extravagant tools a year. Who wouldn't after a lifetime of hard work?
 
To follow up on this, the PM 6" 3 jaw set tru is a very nice chuck and would recommend it to anyone looking for a quality 3 jaw. I did order the Bison 8" 4 jaw combo chuck/backing plate from Small Tools, 2 days later Bill called saying the inventory was wrong and it wasn't in stock and wouldn't be available until October, maybe. He offered me a deep discount on a steel body that's available in a few weeks so, with the way prices are increasing lately, I took him up on his offer. Huge shout out to Small Tools for keeping it real!!!

Mr Jacobs, moving forward, let's not discuss top shelf "work holding chucks" :cool:
 
Back
Top