Well, seems my “bargain” 16N is pretty worn

[mksj]

It an old worn drill chuck, not sure why you would expect it to be better. I have a Jacobs chuck that was in very good condition and use a high quality arbor, but still found that by clocking the chuck relative to the arbor that I could dial down the TIR. Drills have quite a bit of runout, much more than what you are measuring, one reason why on the mill I mostly use mechanic/stubby length drills. All my other drill chucks have an integrated arbor and I also have CNC type chucks that can be used with end mills. They have a TIR of around 0.001" at 3" from the chuck, but they were all purchased new. The Jacobs chuck was purchased used but not abused, actually quite a nice chuck with a TIR in the 0.001" range, but I primarily use my keyless and an ER-32 collet system if I need high precision/stability.

 

[great white]

It an old worn drill chuck, not sure why you would expect it to be better. I have a Jacobs chuck that was in very good condition and use a high quality arbor, but still found that by clocking the chuck relative to the arbor that I could dial down the TIR. Drills have quite a bit of runout, much more than what you are measuring, one reason why on the mill I mostly use mechanic/stubby length drills. All my other drill chucks have an integrated arbor and I also have CNC type chucks that can be used with end mills. They have a TIR of around 0.001" at 3" from the chuck, but they were all purchased new. The Jacobs chuck was purchased used but not abused, actually quite a nice chuck with a TIR in the 0.001" range, but I primarily use my keyless and an ER-32 collet system if I need high precision/stability.

View attachment 414709

I know its an old chuck. That doesn’t mean I shouldn’t try and make it as good as it can be.

Just because something is old and worn doesn’t mean you throw it away and buy a new one, or push it aside for something “better”.

I keep telling my wife that every day….

 

[tq60]

Did you tighten in all 3 holes?

You start in any hole and go snug.

Next hole a bit more

Last hole finish.

Sent from my SM-G781V using Tapatalk

 

[great white]

Did you tighten in all 3 holes?

You start in any hole and go snug.

Next hole a bit more

Last hole finish.

Sent from my SM-G781V using Tapatalk

Yup