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Just bought a Rockwell Mill. can't find model # or serial #

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John_Dennis

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#1
I bought this mill from a guy closing an auto shop.

The motor has been removed by the PO and the wires disconnected. I will try to clean the wires to see if they are still marked, but as of now they are all just black.

I have all the parts for the mill except 1 for the quill feed clutch. I think it is a tapered bushing about 2 inches in diameter.

It is an R-8 quill. I can not find any evidence of a locking pin in the quill. Don't all R-8 quills have some kind of key that stops the tool holder from spinning? Can this be repaired if it is sheared?

Any guesses on the age or model?

Thanks

John

00X0X_9NIgziTlTCi_600x450.jpg

00X0X_9NIgziTlTCi_600x450.jpg
 

Rbeckett

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#3
Rockwell used numbers to denote which wires went to what, I think so don't get too aggressive with the cleaners

Bob
 

wa5cab

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#4
AFAIK, yes. There should be an anti-rotate pin. Rotate the headstock clockwise about 95 deg. and look carefully inside the quill for signs of the sheared off pin. It will be past the end of the taper. As to whether or not it can be repaired, it depends upon how the pin was installed. Extend the quill and look for signs of the pin on the outside. If you find it, then it is repairable.

I bought this mill from a guy closing an auto shop.

It is an R-8 quill. I can not find any evidence of a locking pin in the quill. Don't all R-8 quills have some kind of key that stops the tool holder from spinning? Can this be repaired if it is sheared?

Thanks

John
 

John_Dennis

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#5
I was able to read enough numbers to figure out the wiring on the motor. The start capacitor is bad and I do not see any evidence of a run capacitor.

I ran the motor for 15 seconds without the capacitor just to verify that it would spin up.

Should this motor have a run capacitor?
 

John_Dennis

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#6
I hooked the motor up with a new capacitor. Runs great. The belt is not correct and is too short, making speed changes almost impossible.

Anyone know the correct belt length?

Thanks,
 

walzfab

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#7
If it has not been answered already, the Rockwell 21-100 mill R8 spindle does not have an anti rotation pin, at least my 1968 model does'nt. I just finished a tear down/ R&R of my new to me 21-100.
All bearing pairs had old varnished fibrous grease residue, cleaned in solvent, than repacked with Lubriplate 630AA grease (NLGI #1) Machine runs very quietly, will check spindle runout next.

Rockwell 21-100 mill
Atlas 10100 6*18 lathe
 

Panabax

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#9
If it has not been answered already, the Rockwell 21-100 mill R8 spindle does not have an anti rotation pin, at least my 1968 model doesn't.
My 1960 vintage 21-100 does in fact have an anti-rotation pin in the spindle.

Baxter
 

Shadowdog500

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#10
Here in an Army manual on the Rockwell Mill http://vintagemachinery.org/pubs/2793/4232.pdf
It contains a ton of info including a bunch of different wiring configurations. The wiring configuration on my mill is on page 67.

The motor on my mill had white numbers right on the black wires

I looked this up a couple years ago and found that these mills did not come with a locking pin for the collet. I never found it to be a problem, and as a result I even took the worn locking pins out of my 5C collet blocks as well.

Hope this helps, Chris
 
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walzfab

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#11
I bought this mill from a guy closing an auto shop.

The motor has been removed by the PO and the wires disconnected. I will try to clean the wires to see if they are still marked, but as of now they are all just black.

I have all the parts for the mill except 1 for the quill feed clutch. I think it is a tapered bushing about 2 inches in diameter.

It is an R-8 quill. I can not find any evidence of a locking pin in the quill. Don't all R-8 quills have some kind of key that stops the tool holder from spinning? Can this be repaired if it is sheared?

Any guesses on the age or model?

Thanks

John

View attachment 85276

View attachment 85276
Walzfab here, Greetings, Look at the rear of the machine base on your 21-100 mill (Cast iron base, not sheet steel cabinet) You may find a model-s/n tag/plate (if it's not missing) than google " Rockwell 21-100 mill serial number date"
Or similar verbiage see what comes up
 

Silverbullet

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#12
Hopefully your belt is wrong, if not the pulley may have been changed. I have a drill press with that problem . She looks like a nice machine, I hunted all over to find a small mill there out there. Good luck fixing her up.
 
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HardingeHLV

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#13
I have a combo mill but the head is the same as what you have. If you want, I will take my belt off and measure it for you no problem. I assume your belt is loose even after you've adjusted the tension via the slots in the motor mount plate. Let me know if you need this measurement.

Until then here is a heap of photos of my rebuild on my combo mill.

http://www.pbase.com/ttwells/rockwell_combo_mill_project
 
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