Do I Need To Resurface The Back Of My Chuck

[Swerdk]

Googled it nevermind


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[John Hasler]

Axial runout? Thats the face of the chuck correct?


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Correct.

 

[middle.road]

Also just for kicks, if you have a second indicator, double check it.

 

[Chipper5783]

I would be extremely cautious to cut the face of the spindle:

• It is a critical reference and the manufacturer would have tried to get it right
  
  
• Moving that face back a small amount will have a major effect on the position on the taper (both the taper and the face contact at the same time)
  
  
• That should be a pretty hard surface
  
  
• It is not necessary to touch the face of the spindle for getting a chuck to run its’ best – that is what a mounting plate is for.
  

Chuck mounting / tuning is a very worthwhile exercise (and has been covered on numerous posts on all the usual machinist forums).


You are onto a good topic. It is no surprise that a chuck right out of the box, mounted onto the spindle is not that great. There are a number of approaches one can take (and many opinions), here is what I have done (with credit to numerous folks much smarter than me)


My recollection is that a lot of dialing/measuring was involved, and:

• FIRST and #1, Mount up just the adapter plate and get it sitting properly on the D1 mount. It should pull right up snug against that flat face (no gap at all), and it should be snug on the taper (some of my chucks I have to bump with the palm of my hand to get them loose). If you have to bump the chuck with a block of wood, then open up the taper of the adapter plate(VERY SLIGHTLY – a small amount will move it back a lot) by hand working the taper in the lathe (generally need a second chuck or better yet, a second lathe). This can take several iterations.
  
  
• Once that is done, mount just the adapter plate and mark the position
  
  
• Take a facing cut on the adapter plate. The point here is that even if the face of the spindle is out of whack, the face of the adapter plate will be correct.
  
  
• Install the chuck on the adapter plate and see what you have (chuck up a nice smooth bar, measure radial runout near the jaws and several inches out). This will evaluate radial runout and angular alignment.
  
  
• Decide what to do next, depending on what you want and how well it is working.
  
  
• If the angular alignment is not too good (I assume you have gone through the whole lathe leveling thing), then you would probably skim the back face of the chuck body (again, you need another chuck – preferably a bigger one, chuck up a good sized bar, take a skim cut on the bar to true it, grip the bar with the chuck you are tuning so you can skim the back face.) put it all back together and check again.
  
  
• To address a radial runout, you can undersize the register on the adapter plate, then install the chuck body with the bolts only snug, then with a piece of smooth bar in the chuck, bump the chuck around until the bar runs true, then fully tighten the body bolts (sort of your own set true chuck).
  

• At every step, measure at least 3x before you cut.
  
  
  

The adapter plate is the component that is designed to accept the adjustments. A little skim on the chuck body is not a major sin (simple and easy to do). Cutting the spindle mount? – I’d be extremely reluctant unless there was a very obvious issue and I could not figure out another way to solve that issue.

Let us know what you find out.
Regards, David

 

[Chipper5783]

Oh, and now seeing the title of your OP "Do I Need To Resurface The Back Of My Chuck?" - You picture is of the back of the adapter plate. No, you do not need to resurface the back of the chuck adapter plate (taking even a small amount off that back surface will dramatically effect the mounting taper - which you could also re-cut, but it is a lot of work to get right and is not necessary if the goal is to tune up the chuck).

 

[T Bredehoft]

Lets have a reading with the stem of the indicator parallel the face it's measuring, before we continue the discussion on what to modify.

 

[JimDawson]

In addition to the above, you might want to review these two posts,

http://www.hobby-machinist.com/threads/asian-4-jaw-chuck-adventures-re-post.33311/

http://www.hobby-machinist.com/threads/rant-5c-collets-chuck-d1-4-cam-lock.23838/#post211256 The real work starts on page 2 of this thread, but read through the whole thread.

Both threads show the use of both types of indicators.

 

[Swerdk]

What am I doing wrong I am trying to remove the adapter plate from the chuck yes I removed all the bolts this plate will not budge is there some kind of trick to this I think somebody super glued it in China

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[Rich V]

What am I doing wrong I am trying to remove the adapter plate from the chuck yes I removed all the bolts this plate will not budge is there some kind of trick to this I think somebody super glued it in China

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Did you try tapping it with a brass/lead hammer? Light tapping around the perimeter can knock it lose. I have also used a razor blade in the seam as a wedge to get it started.

 

[Swerdk]

I will try again grrrrrrrr


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