Old Terminology Help

[copter47]

I need a little help here, I have a sheet metal part with a call out for a hole I believe. But I don't know what the call out means and have never seen it before. We are reverse engineering some old print into 3D and need help distiguishing some old terminology.

On the attached file the center hole in the part is labeled 50HI-14?? Does anyone know what that means or has seen it before?

Thanks

 

[thruthefence]

That's "Flange Down" representing the way the stiffing flange is oriented. No clue on the 50HI-14.

 

[GregLocock]

Scaling the drawing by eye it doesn't look as though a 50mm dia hole with a 14mm flange is the right interpretation.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[thruthefence]

Are you with the guys who acquired the Bell 47 TC? Saw the booth in Display in Dallas this spring; nice work, and a labor of love!

 

[copter47]

Thanks for input it is about a 4" hole with about a .25" flange. It would be strange if they listed that hole and flange in mm since all other dims are in inches. We will keep searching for answers.

thruthefence - yes I am with that company that has bought the 47 TC.

 

[Sparweb]

Hey, no kidding, I sat in that B47, too. Pretty!

My guess is that it is a tool reference, not a dimension.
Bell would naturally have standard tools made for flanging holes, (like everyone else) so instead of specifying all dimensions and angles for the lightening hole, the draftsman could just call out the one tool required to make the hole. Done.

We've made a few such tools in our shop, from time to time. One tube + one plug, made with a lathe, fitting together, ready to be squeezed in a hydraulic press, made so as to locate center, shear through, flange the edge, and slide out, all in one operation.

Maybe, somewhere in a factory in Fort Worth there is a shelf with a row of round plugs and sockets that fit together in pairs, and one of them has "50HI-14" stamped on the side.

As for what to do about the part, either locate the tool (lots of aimless phoning around IMHO) or just scale off the drawing what you need and then make your own tool. Bell parts can be flanged 45 degrees in some places, or 60 or 30 in others, depends on where you look. Compare with other parts you may find a similar hole (theoretically made with the same tool) to this one and measure that directly to find out what the end goal really should be.


STF

 

[Yoker]

That's a Hole, Circular Lightening, 45° Flange. 3.50" diameter, 3.00" diameter at the foot of the flange.