Rockwell 21-100 dial question

jimmyb11

Aluminum

Joined

May 3, 2008

Location

Toronto

• Dec 28, 2019

• #1

I have a new to me mill 21-100 and have a perplexing question. There are four graduated dials on the machine, two on the X axis, one on the y and another on the z axis. Two dials have graduations for .200" travel and two are .100" travel. When I measure the travel the .200" give me a true reading and the .100" dials give me a measurement that is half the true travel. Can someone tell me which dials are which on your machine? Are they different or they all the same, which dial goes where on your machine.

Seems weird but sometimes I miss the big picture.....................

Thanks

 

plastikdreams

Diamond

Joined

May 31, 2011

Location

upstate nj

• Dec 28, 2019

• #2

Which axis are the dials on?

Did the .100 give a reading of .050?

 

jimmyb11

Aluminum

Joined

May 3, 2008

Location

Toronto

• Dec 28, 2019

• #3

currently I have the .100" dials on the x-axis and one full revolution has a true travel of .200" yet the dial tells you that you travelled .100".

 

plastikdreams

Diamond

Joined

May 31, 2011

Location

upstate nj

• Dec 28, 2019

• #4

Have you tried putting the dial on y?

 

jimmyb11

Aluminum

Joined

May 3, 2008

Location

Toronto

• Dec 28, 2019

• #5

The .200 dials on the y read correctly, one full revolution travels .200 true travel

 

jimmyb11

Aluminum

Joined

May 3, 2008

Location

Toronto

• Dec 28, 2019

• #6

So the manual says x=.200 Y=.200 z =.100 not sure why the bonus dial is a.100 as it also resides on the awkward end of the x lead screw.

 

L

L Vanice

Diamond

Joined

Feb 8, 2006

Location

Fort Wayne, IN

• Dec 28, 2019

• #7

I bought my Rockwell mill new in 1974. It came from the factory with power feed on the right end of the table, so there are only three cranks and dials. X and Y have 200 division dials and the vertical crank has a 100 division dial. I suppose your mill has an incorrect replacement dial.

Larry

 

jimmyb11

Aluminum

Joined

May 3, 2008

Location

Toronto

• Dec 29, 2019

• #8

That appears to resolve the issue, the bonus dial is what perplexed me, machine working well, thanks to all, great hobby mill, too bad they didn't index the R8 spindle with an indexing pin, it feels odd not finding one but the brake solves the issue of installation. Best to all!

 

crossthread

Titanium

Joined

Aug 5, 2004

Location

Richmond,VA,USA

• Dec 29, 2019

• #9

I have two mills one of which has the R-8 spindle. I'm not a huge fan of R-8 but it works. I would not worry too much about the indexing pin. I'm not a huge fan of that pin either. The mill that has an R-8 spindle lost the pin years ago and I never miss it and it's not worth replacing it in my opinion.