Damn Chuck


When I first started fooling around with metal working 9 years ago, I
bought a Jacobs 14N chuck and stuck it on an Enco 5/8 ths straight
shank to 3JT arbor. It has ALWAYS wobbled. I figured that it was the
cheap shank and recently removed to replace it with a genuine Jacobs
shank since my machining skills have progressed a little bit beyond
the "mark with chalk, cut with axe stage". Appropriate chuck wedges
wouldn't work but the Enco shank was soft so I threaded it and use a
chunk of ¾ inch dia tubing and a 5/8 ths nut to pull the Enco straight
shank off with minor effort. Cleaned up the chuck and brand new
Jacobs 5/8 ths straight shank to 3JT arbor and gently pressed into
place. A reamer blank chucked in the mill has zero run out. Same
reamer blank chucked in the newly shanked 14N drill, 25 thou runout.
Damn. I must have mistreated the chuck badly over the past 9 years.
Got a new Jacobs 14N chuck with new Jacobs 5/8ths SS cleaned
appropriately gently pressed into chuck and tested with reamer blank
today. 12 thou run out on new chuck and shank. Zero run out when
reamer blank chucked into mill collet. WTH???
As an aside, a new Rhom chuck pressed onto cheap HF drill press has
zero run out.
Any insight on either what I'm doing wrong or how to fix it would be
appreciated.
Regards,
Jim
Reply to
JK
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Buy an Albrecht.
But if you wanna use what you have: Seat the taper well. Install the shank with Jacobs chuck into your mill. Tap lightly with a deadblow type mallet and check runout. Tap as needed until you achieve zero runout.
Reply to
skuke
Do a bit of investigating here. Chuck up your arbor and check if it is running true without the chuck on it. if not then note the high spot. Grab the reamer blank with the chuck on one end and the mill on t he other. Check the run out on the taper in the chuck, note the high side. Assemble so that high sides cancel. You may find that your chuck is truly wonkey. Have you had the chuck apart and cleaned and inspected? I went through a similar situation with a 14n and had the arbor and chuck together and apart a few times until I lucked on the orientation that worked. What I suggested above is a bit more scientific. lg no neat sig line
Reply to
larry g
End of discussion. JR Dweller in the cellar
skuke wrote:
Reply to
JR North
I have an Albrecht keyless with a Jacobs arbor 1/2 inch keyless , .023 runout as new , used the cold arbor warm [125] chuck assembly method , never tried to correct it as it does for my rough drilling and I have a Kawasaki keyless that is 35 years old from dad that only has .0003 .0004 for tight work in the mill which I don't do much of any more , do you think I can get the runout out of my Albrecht
Reply to
williamhenry
I don't understand this at all. What's this business about dialing in a ground rod? Indicate the spindle taper directly. Run true? Then carefully put in the arbor alone, and indicate it. Run true? Then carefully put the chuck on the arbor and install it, and only then put in something round, and indicate it. If it runs out badly, return the chuck as defective!
GWE
Reply to
Grant Erwin
Possible. I see two likely sources:
1) The Jacobs arbor is off center. (It should not be, but I would expect it of a Jacobs arbor before an Albrecht one.
2) A jaw in the Albrecht has gotten a burr from a drill spinning in it sometime in the past. (Or perhaps from gripping something the wrong shape -- Albrecht jaws are nicely hardened. New jaws are available, as are replacements for *any* part in an Albrecht. You can built a whole chuck from parts -- but it will cost a lot more than buying a whole chuck assembled.) Good Luck, DoN.
Reply to
DoN. Nichols
Well, if that's the way you feel, you can just go to hell.
Warmest regards, Chuck
Remove bogusinfo to reply.
Reply to
Tom Quackenbush
There is more than a chuck different here.
1. different insertion 2. different arbor or at the very least different arbor insertion at the very least. might try rotating the arbor to a different engagement angle...
Martin
Reply to
lionslair at consolidated dot
Dear Chuck Are you sure that it isn't a New York "damn" and a "thank you" would be a more appropriate response? lg no neat sig line
Reply to
larry g
Grant, Martin, Larry G
Thanks for the insight. I will do as you suggest.
Skuke, JR, I already have an Albrecht. Works like a champ but I save it for the fine stuff.
thanks to all for the advice.
Jim
Reply to
JK
I guess you mean New York _City_? You could be right. And maybe all those folks on I95 that I thought were giving me the finger were just saying, "Howdy"?
Maybe your're right.
Thanks, Jim.
Warmest regards, Chuck
Remove bogusinfo to reply.
Reply to
Tom Quackenbush

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