6-Jaw Spindle Head versus 3/4-Jaw

[matt304]

How valuable is a 6-jaw spindle head for parts making, and how much more valuable is a Bison 6-jaw over an import?

I'm trying to figure out what they really improve in the long run. Is it just easier setup, or maybe more accurate runout on long parts?

I get the idea, more teeth equals more gripping points for a more symmetrical hold on the parts, with more total holding force. I just don't know if a 3 or 4 jaw head really lacks that much to allow a large amount of improvement.

One of the main types of parts I will be working with is long tubes, as I will be making rocket motors up to 2.14" diameter. Of course, flashlights and lasers too, but they are shorter tubes. I will be working with gun barrels in the future, but not just yet.

I have never really found a good read describing why more jaws should be used. I just see people buying them and saying they are better, but would like to know the details.

I have found the import 6 jaw heads for about $300. Where as the same size, 8" diameter head from Bison is going to run $1200 or even $1500 for a 10". I'm just trying to figure out if it will be worth it to me to spend another thousand for a better name.

Also, my lathe includes a 4 jaw head in addition to the 3. When would I want to use the 4 jaw instead of the 3, if I don't end up with a 6 jaw head?

Thanks

 

[unterhausen]

Bison is an import, just a good one.

I don't know if there really is an advantage to having 6 jaws over 3, but generally with 6 jaws you can adjust the chuck so that your part is actually concentric to the spindle. With most three jaw chucks you live with the runout of the chuck.

 

[ODatsBright]

6 jaw chucks also help hold thin wall tubing better as it doesn't distort the metal as much, helping run out as well, but most decent 3 jaws are within a few thousandths anyway. Go for 6 jaw if you're looking to mainly do thinner walled tubing.

 

[precisionworks]

6 jaw chucks also help hold thin wall tubing

+1

For thin parts, 6 jaws are nice. To me, the only drawback for a 6-jaw is that when you need to make soft jaws, you have to make a set of six, versus making half that many for a 3 jaw.

Spend the extra money for the Set-Tru Bison (Poland) or the Buck (Taiwan) or Kalamazoo (American). Scroll chucks are handy for quick jobs, but they don't replace an independent 4-jaw chuck for odd shaped work. A collet chuck is also nice, as is a faceplate. I often change out chucks three or four times a day & it's nearly impossible to get by with just one style.

 

[Davo J]

Hi,
As said above 6 jaw will hold thin wall stuff better. I have never owned one but have never had any trouble holding anything. A turned up plug can be put inside a tube to stop it collapsing.

You can also get 4 jaw scroll chucks that are self centering
https://www.machineryhouse.com.au/Products?stockCode=C723
and 3 jaws are available with the set true feature
https://www.machineryhouse.com.au/Products?stockCode=C2821

Don't take any notice to the prices, they are from an Australian seller.
Most of use guys over here find it cheaper buying from the US and even with shipping it's cheaper than buying through them.

Dave

 

[gadget_lover]

Also, my lathe includes a 4 jaw head in addition to the 3. When would I want to use the 4 jaw instead of the 3, if I don't end up with a 6 jaw head?

The 3 jaw will hold round pieces well. It will also hold hex pieces.

The 4 jaw will hold round or square pieces, but not hex. A 4 jaw with independently adjusted jaws will allow you to hold odd shapes, and to also off-set the piece so that you can turn eccentric lobes.

There is really a use for just about every tool.

Daniel

 

[matt304]

Excellent, thanks.

I think it sounds like I can get by just fine without a 6-jaw, since I don't have very thin tubing projects.

I will be dealing with tubing, though, tubing which will repeatedly be a constant diameter and turned to same specs of 1.5" OD.

My lathe has a D1-5 spindle. So, could someone possibly point out a collet spindle chuck for working with 1.5" diameter tube that they would recommend?

What is required to change spindle head size? For instance, if I want to use a D1-6 chuck, and being that mine is D1-5, is it just a single plate I am looking for? Trying to get the terminology down so I know what to search for.

One final thing I wanted to ask. What is the proper method to properly center the workpiece about to be turned? I know that a magnetic base with dial indicator is used to measure the workpiece. But, is there a physical method that helps to hold the workpiece while tightening it in the chuck, so that you get very close to being perfectly centered every time a round stock is chucked in the lathe? I'm just trying to get all the little tips and tricks covered.

Thanks

 

[precisionworks]

What is required to change spindle head size?

They cannot be changed. A D1-5 spindle nose accepts only D1-5 spindle tooling. It's not possible to install any other camlock tooling (like D1-6) on a D1-5.

is there a physical method that helps to hold the workpiece while tightening it in the chuck, so that you get very close to being perfectly centered every time a round stock is chucked in the lathe?

Any of the 3-jaw Set-Tru chucks will do this & keep round stock centered within +/- .0002"

collet spindle chuck for working with 1.5" diameter tube that they would recommend?

A 16C collet will do what you want. Bison makes a nice one:

http://www.toolmex.com/new/products/product.cfm?id=17031&cid=684_435_418_417&v=1&mc=Y

New England Brass & Tool has the lowest price ... he shows $895 on his website but will give you a lower price if you phone & ask nicely Problem is, the Bison web page does not show D1-5, so you'll need to make sure that a D1-5 back plate is available.

FWIW, D1-5 is not the most common spindle nose and tooling is a little harder to find. That's the spindle on my lathe as well.

 

[wquiles]

I think Barry's experience/example is the best one - it depends on the work "you" will do. In Barry's shop every job is different/unique, so he "has" to have the flexibility to work with stock in all shapes and forms, and admittedly for some parts, at extremely high precision. Changing chucks to match the job is to be expected of a shop like his.

For me, work on the lathe is 95-99% with plain round stock, and almost always on flashlights. For that work, hands-down, a 6-jaw chuck, specially a set-tru chuck, is my IDEAL setup. It does not mater if the stock is 1/2" OD or 3" OD. Put stock in - close the jaws - done (and centered to less than 1/2 mil).

I know the collet chuck has better accuracy and is even more gentle on thin-wall parts, but I am limited to about a little bit more than 1" in OD. Since for the projects that I do I need to routinely work with 1.5" to about 3" in OD, I decided to get the 6-jaw instead.

This was the exact thread in which many of us discussed the pros/cons of the 6-jaw chucks, and where Brian (Mirage_Man) and I bought our Bison set-tru 6" 6-jaw chucks. Here is the thread:
http://www.candlepowerforums.com/vb/showthread.php?t=191705

I am sure if you ask Brian he will tell you, just as I will, that it was the single best purchase for our lathes and the type of work we do. The only serious disadvantage that I see in the 6-jaw is the significantly higher price: a good 6-jaw set tru chuck "is" very expensive, and once you add the required mounting plate you are looking at close to $1000. That being said, the best buy is an used one. Barry tells me that 6" chucks normally have a much gentler life than larger chucks. I did buy a Buck Chuck 6-jaw, 6" that needed some restoration pretty cheap:
http://www.candlepowerforums.com/vb/showthread.php?t=226417

I actually get an email about every other month asking me about my Bison 6" set-tru chuck from folks looking at pictures of my work/projects. I explain to them why I bought it, and how I use it, and they all fall in love with it. That is, until they ask how much is it to buy one. That is the last I hear from them about the 6-jaw.

 

[matt304]

Thanks for the help again, guys.

This is my first time on a larger lathe. The other lathe I worked with was a very small mini-lathe, and so when I chucked parts up, it only had about 3/4" of jaw that held onto the part, and the part would never be centered correctly. I guess with these big through-chucks, problems get resolved quite nicely when mounting the stock.

Precisionworks, you brought up a pretty big point, that is, about the D1-5 not being common. I am actually pretty worried about that, to the point where I might switch the type of lathe I am getting. Neither of these machines have shipped to me yet, and weren't going to until this week.

Basically, what I see being needed is a D1-5 collet chuck that can handle 1.5", and in the future, one which can handle 2.15-2.25". Those are the sizes of tubing I will be using primarily. I honestly don't think I will end up needing the 6-jaw chuck for what I do.

So, if I can find a collet chuck for those right now that will work on D1-5, I will be alright. But if I can't, I am seriously going to consider possibly downgrading to a smaller size D1-4 lathe, or I could upgrade to a D1-6. However, my limit is about $6000 on the lathe, and I don't think I can get a new lathe with D1-6 for under $6k.

EDIT:

Ah nice, I found it for the D1-5, here: http://cgi.ebay.com/16C-Bison-Lathe...3447QQcategoryZ41946QQcmdZViewItem#vi-content

 

[precisionworks]

Ah nice, I found it for the D1-5

That's the non Set-Tru version, Bison #7-862-0601, and it is available in D1-5. The eBay ad shows .001" TIR which is questionable, as Bison does not list a TIR spec for the non Set-Tru chucks. I had a "regular" Bison 5C chuck and could never get it to run under .002" TIR, which is marginal performance for a 5C (or 16C) collet chuck. If you buy that one, indicate a ground rod using a decent collet like a Hardinge & return the chuck if you see over .001" TIR.

http://www.toolmex.com/new/products/product.cfm?id=17030&cid=684_435_418_417&v=1&mc=Y

 

[matt304]

Oh, well I didn't mean the non set through version. On Bison's website, it looked to me like they had a set through version available for D1-5.

 

[precisionworks]

Here's the link to the Set-Tru 16C:

http://www.toolmex.com/new/products/product.cfm?id=17031&cid=684_435_418_417&v=1&mc=Y

In the D-mount backplates, only 3, 4, 6 & 8 are available. Have you looked at the PM1440HD? It has a D1-4 mount and is just under your budget limit.