collet chuck problem

[darbytee]

I just got my Axminster Jr collet chuck on Friday. I put it on the spindle and gave it a turn and had a wobble of over 1/4" at the end of the mandrel bar. The bar was brand new but I checked it anyhow and it's straight. Anyone got any insight on this? I've never used a collet chuck before, so operator error is possible, but it seems pretty straightforward.

 

[Fred in NC]

Two questions: Mandrel size, and collet size.

Collets are designed to hold a round bar of a certain size, with tolerances in the thousands of an inch. For a regular mandrel you should be using a 1/4" collet, which 'most likely hold a mandrel which is just a bit smaller in diameter, usually about .246".

Your mandrel might be too small in diameter, or the collet tolerance not sufficient to go down to that size.

Another question, how did you tighten it?

 

[darbytee]

Fred, It is a 1/4" collet with a standard mandrel bar (berea A size from WC). As for tightening, I used the breaker bar to tighten the chuck onto the spindle and hand-tightened the bar into the chuck.

 

[low_48]

Some collet chucks are self ejecting when you loosen the nut. You must press the collet into the backside of the nut before putting it in the chuck. You have to put the collet on the bench, then press quite firmly on the nut on the collet to force a taper over a ring in the nut. You will hear a firm clunk when it is pressed in correctly. The collet will then stay in the nut . To remove the stock from the collet you will loosen the nut for a few turns. It will then firm up and if you put the wrench back on it will pop the collet off the taper inside the chuck. Your stock will be free. Lots of words, and I don't even know if this chuck works like that. Router collets and CNC tooling work this way.

Rich

 

[its_virgil]

My Beall Collet chuck works this way...also be sure the mandrel is in the collet and not just being caught at the very end of the mandrel. I bring up the tail stock before tightening the chuck nut.
Do a good turn daily!
Don
[

 

[wayneis]

Fred it sounds like you may not have the collett seated in the nut properly. What I was told was to seat the collett in the nut before you screw the nut onto the lathe, then put the mandrel rod in and tighten.

From what I've been told the Axeminster is not a self ejecting chuck, thats one of the knocks against it.

Wayne

 

[darbytee]

Thanks for the advice guys. At this point I've tried every conceivable way that I can think of to tighten the chuck, tighten the bar, tighten the nut, realign the bar to different lengths, etc and all I have to show for it is a $75 paperweight. I'm starting to wonder if the spindle on my lathe is bent. That doesn't seem very likely to me, but I don't know what else to think right now.[!][!]

 

[lkorn]

I had a similar problem with a scroll chuck. Make sure that your chuck is threaded ALL the WAY to the shoulder of the spindle. The threads themselves WILL NOT ensure straightness. There is too much play in them. Thread the chuck on and tighten it to the shoulder, this is what makes it square the the axis of rotation.

Originally posted by darbytee
<br /> all I have to show for it is a $75 paperweight. I'm starting to wonder if the spindle on my lathe is bent. That doesn't seem very likely to me, but I don't know what else to think right now.[!][!]

 

[Fred in NC]

If the chuck's body is not threaded deeply enough, it will not reach the spindle's shoulder. If this is the case, you might need a spacer washer behind it.

I have some nylon and some PVC washers, 1" bore, 1/4" thick, 2" diameter, that were made for use with the indexing plates. These might work if the above is true.

 

[Rifleman1776]

Big advantage of belonging to a local woodworking/turning club. You can call on friends with experience. Even though the backing with nylon washers is always a good idea, I would get on the phone with tech support and have walk you through checking it out. If there is the slightest doubt that the item might be defective, insist on an exchange. I went through four defective chucks from PSI before getting a non-defective one. They were very good about working with me to assure I was satisfied. These businesses are highly competitive and they know one unhappy customer can cost them a lot of business from that customers circle of influence. And an international internet discussion forum is a HUGE circle of influence.

Originally posted by darbytee
<br />Thanks for the advice guys. At this point I've tried every conceivable way that I can think of to tighten the chuck, tighten the bar, tighten the nut, realign the bar to different lengths, etc and all I have to show for it is a $75 paperweight. I'm starting to wonder if the spindle on my lathe is bent. That doesn't seem very likely to me, but I don't know what else to think right now.[!][!]

 

[Old Griz]

Fred, I am sure that if you call CSU and ask for Nils he will take care of any problems you have... I harass him occassionally and he still talks nicely to me []
I used my Axminster for the first time yesterday and tested all 5 mandrels I have and all of them ran true and straight... and these are old suckers.. I was considering buying some new mandrels, but not anymore...
Quality Control on these items is usually very good.. but occassionally one gets away from them.. I know I used to do that for a living.. [xx(]

 

[darbytee]

Thanks for the responses everyone. When I left work yesterday I checked my messages and had one from Nils regarding this post and wanting to help me fix the problem. I never called him, he took the initiative and called me. That is why I love doing business with Craft Supplies.

By the way, I think the problem is exactly what Larry and Fred said. The collet chuck is not threaded deeply enough to mate with the shoulder of my spindle. Thanks again.