6 Jaw Chuck

[dennys502]

Finally getting my lathe set up. My precision level came so I was able to level it and decided to get a new chuck as the one that came with it was a 6 inch that has seen some use. I decided to get a 8" 6 jaw adjust tru from Shars. I turned the back plate for it so that it was snug - I had to use the bolts to pull it up tight. It had .0015 for run out so I decided to take another .008 off. I used a 1.5" Danly die post to adjust the run out.

I also got a 5c collet chuck with a D1-4 mount. The run out was supposed to be .0006 but turned out to be .008. I got this from toolsprecison on ebay and later found out it was actually CDCO in Illinois with another storefront. I think from now on I'm going to have to really check out who the store front belongs to before buying.

 

[carlquib]

What kind of run out did your collet chuck have? Is the bar parallel with your spindle or do you have angular run out? I got one of those d1-4 5c collet chucks from little machine shop a number of years ago, mine is an adjust true style so I was able to get my run out to almost nothing. The chuck holds very parallel with my spindle axis with good collets but the collet makes a huge difference. Some of my Chinese collets are fine but others I have just replaced with good made in USA collets. I'm partial to royal or hardinge. I have had pretty good luck with cdco, but I have mostly just bought BA, CA tools holders and a few of his diamond grinding wheels from Frank.

Hello, my name is Brian and I'm a toolaholic!

 

[dennys502]

I have a little taper in the head about .0015 in 6 inches so I need to get that set yet. The collet chuck I got is not adjustable like the 6 jaw. All of my collets are either Hardinge or Royal.
The owner of CDCO is listed as Zinan Fan but he must use Frank as an alias.
I think I'm just going to return the collet chuck and not do business with him again. The quality of some of the chinese tooling isn't bad but when the seller misrepresents what he is selling that is another thing.
I noticed on his ebay page that someone left a negative comment about the same collet chuck having a runout of .006 instead of .0006. So they vary quite a bit. I left my comment before checking so he didn't get a negative from me.
I bought my BXA holders from Shars and so far their quality has been good so I think I will stick with them.
Being retired I don't have the resources I used to so I can't afford the more expensive tooling.

This notice is posted on the ad for the chuck on Ebay - "Upon receipt, if found defective, please contact us. we will arrange the return or credit". So it is probably a hit or miss if you get one that is within the specs listed.

Denny

 

[mksj]

Shar's has higher quality 3 and 6 jaw scroll chucks, like the one you purchased that have tighter specs and better TIR. There chucks are about 1/2 the price for a comparable Bison. The 6J scroll looks to be nicely made and the TIR is well within spec. of what one would see with a non-adjustable back plate.

I have been through several 5C chucks, the generic direct mount Chinese ones that are sold under various names are usually are hit or miss on the TIR. Most often miss by 10 fold. There was an adjustable Chinese 5C chuck with a D1-4 back plate that was reasonable from LatheMaster. The site is long gone, but he still sells these on eBay and he can be contacted through SALES@LATHEMASTER.COM. This is a Chinese 5C chuck with a set-tru type back plate. This is a very decent chuck and can hold a TIR of better than 0.001". Shar's has a direct mount that claims 0.0006" TIR but looks like the generic Chinese type to me, it is expensive and they charge a lot for shipping. At their price, I would get the LatheMaster adjustable or save my pennies for a Bison direct mount.
http://www.ebay.com/itm/5C-COLLET-TRU-SET-LATHE-CHUCK-FREE-SHIPPING-IN-US-/381953996484
http://www.shars.com/5-5c-collet-chuck-d1-4-cam-lock-mounting

Beyond the generic Chinese 5C chucks, you probably need to step up to a Bison Direct mount which states a TIR 0.001, or a set-tru type which gets you down to 0.0004, or consider a different collet system. Gator is slightly cheaper, but there seems to be more postings of quality issues with their chucks these days.

 

[dennys502]

I like the adjustable back plate but you shouldn't need it for a collet chuck. I'm going to have to shop around a bit and see what I can find. I would get the Shars but they are out of stock - they were when I ordered this one and still are.
I think I'm going to put a 1" collet with a piece of ground A2 shaft and mount it in the 6 jaw and see how far the backing plate is out. It would be a pain but I could machine the back plate so it is true if it didn't require too much taken off.

 

[petertha]

I like the adjustable back plate but you shouldn't need it for a collet chuck..

I'm not sure that's necessarily true. Even so called high quality brands offer direct mount chucks & also adjustable back plate styles presumably for more precision. Check the specs (which as you say is a it of crap shoot in terms of what they claim vs. reality). For example my Bison D1-4 direct mount 5C collet chuck is consistently within 0.001". This is measured on the collet face directly, no collet or stock in there which adds other layers of uncertainty. Actually it seems to favor one particular D-pin orientation configuration to get this, in another position it can be another 0.0003-0.0005"so my take is the run-out error is within the pins tightening & spindle nose mount. But for example Bison also offers their Set-Tru or Tru-Set or whatever they call their system & you can dial that in to whatever level you have patience for with the 4 back plate screws, probably pretty close to zero assuming your collets & chucked part are also good to that.

If I had to do it again I would buy a adjustable back plate style of 5C chuck specifically for this reason. Dialing in concentricity is the same principle as an independent jaw chuck jaws. But once set up it the Set-Tru type should stay that way for a while I imagine.

ps - I just bought some smaller (5") Gator chucks for my rotary table & also got the D1-4 back plate for the heck of it. I noticed they have an equivalent to Bison Set-Tru system. They seem like pretty good quality to me but are much lower cost (at least in my neck of the woods). Good luck!

 

[dennys502]

I guess I was looking at it from the standpoint of the 6 jaw vs the collet chuck. The scroll on the 6 jaw adds a variable on the concentricity of the jaws - so depending on the diameter of the part it could need to be adjusted.
If the collet chuck is in spec .0006 TIR as advertised it should never need to be adjusted as long as the collets are to spec.