Help Identifying Callouts in an Old Drawing 1

[stormloader]

Hello everyone,

I have this old shaft drawing and I’ve circled several callouts in green. I guess they are geometrical tolerances, but I’m not exactly sure how to interpret them. I also don’t understand the numerical values inside their bubbles—what do they mean, and how should they be read?

Any insight into this would be greatly appreciated!

Thanks in advance.

 

[Brian Malone]

The items you have circled don't appear to be be geometric tolerances to me. They seem to be defining reference Datums or inspection points or flag notes. Do you have additional sheets of the drawing with general notes, etc.?

Amazing tech described by your drawing! The thin-walled (~.09~.12 inch) shaft geometry is a challenge to form and finish, then the inspection is an equal challenge for set up alone and interpretation.

 

[GregLocock]

I think that's a bit of a clue for B.

and this for A

 

[mfgenggear]

I will post in s little bit. But agree with previous post. Hard to believe that some of these drawings are before our times. And the machinery was mostly manual.
I started doing this type of work.
Challenging is saying it mildly.

 

[WKTaylor]

Looks like company specific drawing system... pieces from here and there... NOT MIL-

 

[RoarkS]

1st off, not like anything I've seen/I don't recognize the formatting. BUT It sure feels familiar.

Looking at -A- I'm guessing a Datum simulator/gage tooling, is installed into the associated bolt circle to establish a central axis from which A1 dimensions are pulled. Basically saying hey this dimension is associated with gage A, and A1 is probably a bar offset a known distance from the central axis for sweeping a test indicator on OD surfaces. All the A1 dims appear to be the most unsupported portion of the thinwall OD, thus check in this area per the note "for this length" 2.850 for the first A1 on the left.

If I had to guess I bet the part sits flat on -A-, in a vertical orientation. B is probably mounts on the end of A for checking length. C, is probably a "complication"... an "add on" to the -A- simulator. to grab the diameter of the Hirth coupling. D, is probably a dial indicator to position the minimum of that groove to establish part clocking because that clocks the 1 offset hole in the 12 hole BC. E, is a tool that gets concentricity between the inside and outside... I bet its a "C" frame that slides onto or clamps onto the A axis.

I bet I know exactly what that tool looks like... at least I know what It looks like in my head.

I've had to build tools like this for gaging DCMA parts designed from way back before a CMM, and no alternate means were approved. Building a really nice datum simulator to sweep test indicators from was the only way. We finally got smart and just convinced them the CMM could pull it off.

Absolute nightmare part.

 

[GregLocock]

I liked the way the effect of WW2 rationing was still present. Thou shalt use the letters in alphabetical order for each different attribute. So you have view A datum A section A-A, none of which are necessarily related.

 

[ghostdigital]

Those are Datum lines, targets and areas.

The balls indicate the type of simulators for gaging and location

 

[WKTaylor]

MAYBE MIL-STD-1 [and thru MIL-STD-24] might help interpretation... The MIL and the drawing are about the same era.

also NAS30 and NAS31 [surface roughness C/Os might help.

What company's name is on the drawing?