Is there a consensus of opinion re: Bison lathe chucks?

[cazclocker]

Yesterday I was poking around in the back of a drawer at my jeweler's bench where I do most of my work with my Rivett watchmaker's lathe. I found a little 2-3/8" 3-jaw scroll chuck with a theaded rear spindle made by Bison. I bought it brand-new years ago (I think from Penn Tool Co.) and I realized that I've never, not even once, used it!

I can't really remember why I never used it, but later today I plan to swap the Sherline 3-jaw scroll I've been using for the Bison and see if the Bison will give me better concentricity than the Sherline. The Sherline has been adequate for rough work, but I just can't get any better than .005" - .008" axial runout with it.

The Bison is laser-etched MADE IN POLAND, 3286-2 3/8" -16BC.

It appears to be well made, with firm even drag when closing or opening the jaws.

I'm unfamiliar with Bison's reputation. Anyone here have/use one?

I'll take a few pics later this morning and post them here. I was considering selling it on eBay, but maybe I'll keep it if it checks out to be better than my Sherline.

EDIT: I'M ADDING PICS NOW

 

[Winegrower]

I have a 10" 4 jaw and a 6.25" three jaw from Bison. They are really well made. I reported here about trying the 3 jaw with a reference pin and finding literally zero runout to tenths. The spindle runs about 1.5 tenths by itself, so the clocking must have compensated. It's very impressive nonetheless. So I think they're great.

 

[mksj]

Bison chucks are highly regarded as top end chucks, they are made in Poland and are very well made. There are some spinoffs of the Bison chucks from employees that left and stated their own companies which essentially are copies of the Bison. These include TMX chucks are also manufactured in Poland and are equivalent or slightly below the Bison in quality, Gator chucks are made in China and they get mixed reviews as far as quality. I have two Bison chucks, and on one I use a Gator back plate because it was 1/2 the cost of the Bison. It is good enough for my level of work but I would buy a Bison/TMX chuck over a Gator, I also had a discussion with a chuck distributor and he indicated the same thoughts.

 

[Chipper5783]

Sure, the Bison chucks are very good. Of course a thrashed Bison chuck, is still just a thrashed chuck. They are expensive, but good quality and expensive go together. I have 3 Bison chucks right now (the 6” 6J sure is nice) and I have a 10” 4J on the way. There certainly are other manufacturers of quality chucks, but they are also pricey.

 

[cazclocker]

So I just added some quick pics of the little Bison 3286 to my original post. The more I look at it and feel the smooth action as I open & close it, the more I like it. I'm going to have to mount it to my little Rivett (remember, it's ONLY a watchmaker's lathe - it's not big, but capable of astoundingly accurate work).
I tried to find it on the internet and I found what seems to be my chuck minus any photo. But THE PRICE... $704.00 for a 2-3/8" 3-jaw? That must be MSRP. I don't remember what I paid, but it was something a LOT less. Here's what I found: https://store.bison-chuck.com/us/en/3-jaw-self-cent-chuck-3286-2-3-8.html

Both the Bison & the Sherline 3-jaw have the same rear mounting threads - 3/4"-16. My Sherline has a handmade spindle mount that is modeled exactly per the original Rivett 2B watchmaker's lathe collets. All I have to do is unscrew the mount and put it on the Bison to test it out.

Anyway, here's some pics of the Sherline 3-jaw I've been using. I have the jaws reversed because I was working on a project with 1-1/4"-diameter brass stock.

 

[benmychree]

I have never seen two things on this posting, firstly, a 3 jaw chucl with an open back like the Bison, and secondly, a 3 jaw chuck where the same set of jaws can be reversed in the chuck body; this must mean that to function in that manner, they would have to have convex curvature on both sides that bear on the scroll, meaning that they would have little bearing on the scroll when reversed (Sherline), and yes, the Bison chucks are very good quality, and they used to be quite affordable back in "the day".

 

[NCjeeper]

+1 on Bison stuff.

 

[Shotgun]

I have never seen two things on this posting, firstly, a 3 jaw chucl with an open back like the Bison, and secondly, a 3 jaw chuck where the same set of jaws can be reversed in the chuck body; this must mean that to function in that manner, they would have to have convex curvature on both sides that bear on the scroll, meaning that they would have little bearing on the scroll when reversed (Sherline), and yes, the Bison chucks are very good quality, and they used to be quite affordable back in "the day".

The 6" chucks (3 and 4 jaw) I had on my Craftsman had reversible jaws.

 

[woodchucker]

I have never seen two things on this posting, firstly, a 3 jaw chucl with an open back like the Bison, and secondly, a 3 jaw chuck where the same set of jaws can be reversed in the chuck body; this must mean that to function in that manner, they would have to have convex curvature on both sides that bear on the scroll, meaning that they would have little bearing on the scroll when reversed (Sherline), and yes, the Bison chucks are very good quality, and they used to be quite affordable back in "the day".

so probably trying to lose weight on a small lathe like that. I imagine the key is like the key on a drill chuck.

 

[cazclocker]

I have never seen two things on this posting, firstly, a 3 jaw chucl with an open back like the Bison, and secondly, a 3 jaw chuck where the same set of jaws can be reversed in the chuck body; this must mean that to function in that manner, they would have to have convex curvature on both sides that bear on the scroll, meaning that they would have little bearing on the scroll when reversed (Sherline), and yes, the Bison chucks are very good quality, and they used to be quite affordable back in "the day".

I've never seen an open back chuck of any configuration either! I've never used the Bison, but it must be dead simple to clean. As to your other point, I've never seen a 3-jaw scroll chuck in which the jaws were NOT reversible... the teeth on the backside of each jaw are (as you correctly guessed) ground with a double convex shape, so regardless of orientation the jaws have a single point to bear on the scroll.