Collet Chuck - Large Runout... Help?

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guitarchitect

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Hoping someone can see something i'm missing here!

I ordered the Beall Collet Chuck from Lee Valley, and when I received it I put it on my lathe and chucked up a piece of rod stock. It was clearly wobbling so I got out my dial indicator to check - runout is over 0.010", on the body of the chuck! I checked everything - the spindle/headstock has less than 0.0005" runout... the inner MT2 taper has the same. The face of the spindle is also the same. When I put on the chuck, it's odd - the end of it has the same minimal runout as the back plate, but both the side and the inner taper have 0.010" or more. When I told the Beall company they said to have Lee Valley replace it because their tolerance is 0.003" or less.

I got the replacement today, and it's exactly the same. So either I have bad luck and my LV has a batch of rejects, or there's something wrong with my setup. Has anyone seen this before, is there something I'm doing wrong? Before anyone suggests it, I don't think shimming is a viable option since the chuck needs to seat properly against the headstock. Beall even said that's where the accuracy comes from (I was worried that my threads were the culprit). I've cleaned everything with acetone to ensure it's all as clean as possible, but to no avail.

Here's a video of it in action:

ColletChuckRunout.mp4

drive.google.com drive.google.com

Clip1: Indicator on headstock
Clip 2: Indicator in same spot running on collet.
Clip3: Indicator on headstock, where the chuck seats
Clip 4: Indicator on the front of the chuck
Clip 5: Indicator in the taper of the chuck
 
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Have to say I bet it has to do with something on your end. Bealle is a great company that makes great precision tools. I have 3 of their collet chucks. One thing that many people do not do is seat the collet in the top nut before screwing it onto the body. you do not just place in body and expect the top nut to seat itself. You do need to use the proper collect for project. If you have a ring behind the chuck and spindle head maybe take that off and take measurements. It could be warped or flattened out of square.

Just looked at your video and where you are taking measurements to me is irrelavent. yes you show your headstock is true. But inside the chuck does not mean anything. That collect compresses there. The outside of the chuck means nothing because again it is the collet that holds the piece. I suggest you set the chuck up with a rod that you know is perfect and take meassurements on the end of the rod and see if it spins true.
 
Unfortunately I did that as well and the rod (a selection of different drill bits) measures the same runout directly adjacent to the collet. Unfortunately I haven't got a gauge or reference pin but if the drill bits all measure the same as the chuck it definitely indicates something! I was indeed putting it together properly... Collet in holder, put collet onto chuck, feed in the stock and tighten. I'm happy that my collets are at least not making it worse, and it suggests that once everything is assembled it will run true.

I took the measurement on the face of the spindle because that's where Beall said the important interface was. I wanted to rule it out as a cause for them as well as myself (and to their credit, JR responds quickly and has offered to pay shipping to check it out on this one.)
 
The runout on the face of the spindle, 0.001", could be enough to kick the chuck over enough to get the 0.010" on the inside of the chuck taper. If you still have the chuck locate the high spot on the spindle face and on the opposite side, low spot, put something as close to 0.001" on it and screw the chuck on. I doesn't have to be tight, just gently snugged. Ideally a 0.001 feeler gauge but a piece of kitchen foil is very close. If that reduces or eliminates the runout then you know it is your lathe that's doing it and can see about getting a machinist to face the lathe spindle.
 
Curly said:
The runout on the face of the spindle, 0.001", could be enough to kick the chuck over enough to get the 0.010" on the inside of the chuck taper. If you still have the chuck locate the high spot on the spindle face and on the opposite side, low spot, put something as close to 0.001" on it and screw the chuck on. I doesn't have to be tight, just gently snugged. Ideally a 0.001 feeler gauge but a piece of kitchen foil is very close. If that reduces or eliminates the runout then you know it is your lathe that's doing it and can see about getting a machinist to face the lathe spindle.
Click to expand...
i guess the weird thing is, if it was seating eccentrically wouldn't that also show in the end of the chuck? After measuring the outside and the taper I thought "Oh, it must not be seating properly" and figured I'd see the biggest runout at the face of the chuck... alas it's quite parallel to the spindle, and that's what has been most confusing. Not only that but the runout on the chuck is the same front to back, which to me indicates there's no skew to it (otherwise it'd be minimal near the headstock and larger at the end of the chuck)

I did try shimming it early on but I couldn't get it to sit properly - perhaps i was using too thick of a shim. i'll try foil and see if that helps - last thing i want to do is marr the spindle with some feeler gauge offcuts!
 
@guitarchitect

Hmmm .... in the last 5 secs of the video, I seem to detect the functional "stem" of the gauge moving in and out ... in the direction of the rotational axis.
I am sure you would have the gauge securely mounted though. . Anyway, I mention that for what it's worth even if that is nothing !!!
 
If you've not done this already, try a thorough inspection of the threads on your drive spindle (my eyesight isn't wonderful, so I use Optivisor magnifiers to help out.)

If you see anything that doesn't belong, clean the threads with a brass brush and solvent (acetone or alcohol).
 
magpens said:
@guitarchitect

Hmmm .... in the last 5 secs of the video, I seem to detect the functional "stem" of the gauge moving in and out ... in the direction of the rotational axis.
I am sure you would have the gauge securely mounted though. . Anyway, I mention that for what it's worth even if that is nothing !!!
Click to expand...
Not sure what you mean? On my dial indicator the entire plunger itself moves, the only part that doesn't is the wider part closest to the dial... So that stem has a good 25-35mm that moves. Unfortunately it's all I've got! I've checked it dozens of times and it always reports the same amount of runout, give or take half a thou
 
By functional "stem" I just meant the spring-loaded plunger. . Bad choice of words on my part.
I was thinking that the mounting of the gauge might not have been sufficiently secure ...
... allowing some slight angular movement of the whole gauge.
In the last part of the video ( about the last 5 secs or a bit more ) the whole gauge is at an angle to the rotational axis.
The tip of the plunger is riding on the internal surface.
So, if the angular orientation of the gauge changes slightly that would cause an erroneous measurement of run-out.
 
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Are you sure the collet is seated correctly in the chuck? From experience on a game call forum, the collet chuck problems were usually operator error, the collet not being seated properly.
 
May I ask what prompted you to do all this measuring?? Have to remember this is a wood lathe and not a metal one. I never checked the measurements on mine because it never had any effects of anything I use it for. Just curious because those measurements do not seem all that bad. I know that company will stand behind their product though.
 
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