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View Full Version : Bison Collet Chuck: Set-tru or Direct Mount?



Littleleroy38
07-03-2010, 12:07 AM
Gents,

I have searched through the previous posts on the topic of Bison 5C collet chucks and discovered that ownership is about evenly divided between the set-tru version and the direct-mount version. As I understand it, the set-tru will allow one to obtain maximum accuracy for one particular diameter, but is more expensive and will require machining the backplate. The direct mount is cheaper and has less overhang, but is not adjustable.

In my case, the chuck would go on a D1-4 spindle in like-new condition. I will be turning 3, 4, 5, 6mm axles for steam locomotives.

I would like to hear what current owners have to say about their chucks. How did you choose between the two? Would you go the other way if you had to choose again?

Thanks.

chipmaker4130
07-03-2010, 12:27 AM
With my old Buck 3-jaw, the 'set-tru' system is independant of the mount. Are you sure you have to give up one for the other?

Oops! It is late and I'm not paying attention. I see you are referring to the collet chuck. I have the Bison for which I had to machine a generic D1-4 backplate. It has no 'set-tru' type adjustment, but it is repeatably dead-on so long as I make sure to index it to the spindle the same way each installation.

hornluv
07-03-2010, 08:24 AM
In your case, with the cam lock spindle, you shouldn't really need the set-tru. Just make sure you machine the back plate in situ and always put it on in the same spot as chipmaker said. I have a set-tru collet chuck but I also have a threaded spindle.

squirrel
07-03-2010, 08:46 AM
The set tru is the better choice, and that just depends on the accuracy you need if the part is to be machined on opposing ends. Or, if you are trying to rework a previously machined part you will need to get the concentricity dialed in near perfect. If you are only single end turning it does not matter a whole lot.

Littleleroy38
07-03-2010, 09:04 AM
I would be working both ends of a part to make shoulders.

JCHannum
07-03-2010, 09:28 AM
If it is a collet chuck on a D1-4 spindle, it should not require the Set-Tru feature, it should be repeatable from the manufacturer. Bison is a good product and should be repeatable, the cheaper clones, less so.

That said, there are three components involved, the spindle/mount, the chuck and the collet and stack up can throw the job off.

If ultimate accuracy is the goal, dedicated fixtures can be easily fabricated to acccomplish the job for far less money than the cost of a collet chuck.

Littleleroy38
07-03-2010, 03:05 PM
JCH: aside from using a collet block in a four jaw chuck, what other types of fixtures could I use?

JCHannum
07-03-2010, 03:17 PM
A piece of round stock in the three jaw chuck, drilled and reamed in place with a setscrew to hold the part being turned will work as well as any collet on the market.

Drill & tap for the retaining screw first, then chuck it up, drill & ream to size. Do not remove it, prep the axles first and do all the shoulders at one time. It probably can be reused if you have a good three jaw and mark it's position relative to jaw #1. You can also use a four jaw and dial it in if reusing.

Another option is a v-block and angle plate on the faceplate. Faceplate work is often overlooked, but the faceplate is a versatile and inexpensive workholding device for the lathe. I would purchase a faceplate long before a collet chuck.

Boucher
07-03-2010, 03:32 PM
What is the advantage of using the collet chuck over just using the collets?

If you have to buy the chuck and change it when you use it, I don't understand. I would think the collets working in one bushing in the spindel would be more accurate.

Littleleroy38
07-03-2010, 11:19 PM
Byron:

Initially, that was my approach. And the company even sent me a collet drawbar tube and handle, but they didn't realize I have what they called a "big bore" model with an extra large spindle. So it turned out I can't get a collet closer after all unless I make one (beyond my abilities) or look for a used Royal or something else.

D_Harris
07-04-2010, 01:10 AM
This is an interesting subject and I also debated getting a Bison, clone. :D

Here is a picture of my 5C collet chuck with a collet inserted: http://s290.photobucket.com/albums/ll257/Statenislander/Tools/?action=view&current=IMG_0213.jpg

http://s290.photobucket.com/albums/ll257/Statenislander/Tools/?action=view&current=IMG_0216.jpg

But then again I also have a mini lathe. I really can't see putting my collet chuck in a chuck on this machine. (I won it on eBay some years ago for something like $30+).

Have you considered this? http://www.sc-c.com/metallathe/MLA21.html

Darren Harris
Staten Island, New York.

Littleleroy38
07-04-2010, 10:44 AM
Thanks, Darren.

Those are very interesting possibilities. With the kit, I would have to attach it somehow to a D1-4 backing plate. It looks simple enough and cheap enough that I will contact them.

I will look at collet blocks too. Or, as JCH has suggested, a simple piece of round stock bored to the correct dimension and held in a four jaw would work. That would be so cheap that I could do several for different dimensions. As always, it will come down to time versus money.

D_Harris
07-04-2010, 11:03 AM
Thanks, Darren.

Those are very interesting possibilities. With the kit, I would have to attach it somehow to a D1-4 backing plate. It looks simple enough and cheap enough that I will contact them.

I will look at collet blocks too. Or, as JCH has suggested, a simple piece of round stock bored to the correct dimension and held in a four jaw would work. That would be so cheap that I could do several for different dimensions. As always, it will come down to time versus money.

The great thing is that you make it on the machine you'll be using it on. This will beat any Bison chuck as far as accuracy is concerned.

You can order the drawing/instructions first and then decide from there.(I would have already, but at the moment I can only use PayPal or money orders, which are not the payment options he mentioned to me).

Darren Harris
Staten Island, New York.

lakeside53
07-04-2010, 11:30 AM
What is the advantage of using the collet chuck over just using the collets?

If you have to buy the chuck and change it when you use it, I don't understand. I would think the collets working in one bushing in the spindel would be more accurate.

One is that you can choose a collet that is not the same as your machines' native size. My smaller lathe takes 3C; with a chuck I can use 5C. On my larger machine, it uses 5C so there really isn't a size advantage, but.... I could put on an ER40 chuck and use the same collets as my BP!

Another is that opening and closing spindle mounted collets can be more time consuming than with a chuck (depending on the system).

The easy way to mount ER collet chucks is to buy the "straight shank" version and mount it in 4 jaw. I recently acquired an ER25, ER16 and ER11 (they came as a "lot"). I can use them to hold work in a 4 jaw, or, to hold my tiny boring bars in my CXA boring bar holder. The Chinese ER collets with straight shank can be got for as little as $30 (surprisingly decent quality).... and quality brands for less than $200. Makes it hard to justify a dedicated direct mount chuck, and the 4 jaw gives you "set-tru".

D_Harris
07-05-2010, 08:02 PM
This is the cheapest I've seen these 5C collet chucks.

http://www.cdcotools.com/

Darren Harris
Staten Island, New York.