Can this chuck be improved?

Will, sorry for my being so brief. Carry over from my days working for the railroad telegraph.
At first I thought that this thread was (or going to be) merged with another thread and be discontinued.
Thanks for clearing that up for me.
Mike
 
rock breaker,
the marker you used for the hash marks on the chuck (in above photo) might work on the taper to show up contact spots. Lipstick might smell better but you would have to go in some scary places to find blue lipstick.
 
The hash marks are layout dye; it has worked for me before. I lost the better half of the marriage just over 7 years ago so pink lipstick isn't a problem but I would have a problem with blue and the scary places. I don't recall any rough spots on that taper but will double check tomorrow. Shars Tool has 6.25" scroll three jaw D1-3 chuck with 0.003" TIR advertised but am not sure of the price. It would definetly cure the problem at hand. I have failed to mention the wobble visible when using this chuck. Back to Shars, they sure have a nice information chart for these chucks on their website.
Have a good day
Ray
 
I'm not certain, from the picture that you posted but, that looks like it could be a flat-back chuck plus adapter plate. Maybe the adapter plate is the problem and the chuck itself is OK.

I asked the question in #3 above: Is it a chuck plus adapter plate or is the D1-3 integral to the chuck body?
 
I don't know if this is advisable, but I was wondering if you have a little wear on the spindle nose and you have a TPG or some kind of lathe ginding device wich you can set at 7dgr 7min 30s and regrind the nose, but you then have to make a backplate for the chuck or modify the old one a bit. Is this a total NO NO or is this doable? I got a new Bison 4jaw scroll chuck about 2 years ago and made the backplate and thought about this but I decided against it at the time. I have about 0.003" runout,but If I can better it in this manner, I would give it a go. I hoped for better then seeing that I machine everything true to the lathe nose. It took alot of putting up and taking of the chuck. What do you guys think?

Michael
 
Is the backing plate hitting on the Morse taper adapter on the spindle? Just another thing I would eliminate as a cause.
I would unbolt the chuck from the back plate and get it mounted and figure out where the interference is.
Number each of the pins on the back plate and remove them and check them in the holes individually. Then check the bare back plate on the spindle.
Joe
 
Michael,

Just to understand your question, are you saying that your DIY backplate has .003'' of runout or the spindle nose has that much runout?

If the spindle nose and index surfaces are true I would certainly not touch them. If there is runout on the spindle from wear and we are fitting a new backplate I would look for another way to zero the chuck than grinding the spindle.
A spindle grind is an extreme last resort and when justified is very risky for an inexperienced person to do.
So I vote NO-NO until further notice.
 
Tozguy said:
Michael,

Just to understand your question, are you saying that your DIY backplate has .003'' of runout or the spindle nose has that much runout?

If the spindle nose and index surfaces are true I would certainly not touch them. If there is runout on the spindle from wear and you are fitting a new backplate I would look for another way to zero the chuck than grinding the spindle.
A spindle grind is an extreme last resort and when justified is very risky for an inexperienced person to do.
So I vote NO-NO until further notice.
Click to expand...
Hi Tozguy. The runout is on a testbar clamped in the jaws. As far as I can remember, and I am saying this under correction,the nose and face was good,I'll have to check. I am kind of also asking this question, because I think there is some others that thought about it. I just need to clarify that I think my experience level is not that bad,since I have been at this this since 1996 and been doing this full time from home since 2011. And please Tozguy I am not saying this in any aggressive way or to agitate you or in any kind of bad manner, I am simply stating a fact. I hope you understand my meaning. That being said,lets say your spindle bearing is perfect, spindle face is good,but the taper is the problem, can it be said that grinding the nose could be the next step? I must just add that when I did the backplate,I paid extra attention to try and make the taper and face surfaces to make contact when the chuck is fastened. Keep in mind when I did this,I did it to the best of my common sense(wich can be dodgy :big grin: ).
 
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