Locating Hex-shaped Pin Holes
Locating Hex-shaped Pin Holes
(OP)
Plastic part. I have a pattern of 4 hex holes for round pins to go into. How do I locate the hex hole pattern? My first thought is to treat it kind of like a round hole pattern, but show dimension across the flat of one hole as follows:
4X .072 HEX
|LOC|DIA .005M|A|BM|
Upon doing some research, I seem to find the solution to be using profile of the hex shape, but I'm not sure how that helps to locate the hex.
Any and all help and/or examples is appreciated.
4X .072 HEX
|LOC|DIA .005M|A|BM|
Upon doing some research, I seem to find the solution to be using profile of the hex shape, but I'm not sure how that helps to locate the hex.
Any and all help and/or examples is appreciated.





RE: Locating Hex-shaped Pin Holes
You consider cylindrical envelopes created inside of hex holes and locate those envelopes as if they were cylindrical holes.
Functionally you place cylindrical pins into the holes anyway, so the (imaginary) checking fixture will have set of round pins to check hex holes as well, which is exactly what the idea of irregular FOS is.
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Locating Hex-shaped Pin Holes
Thanks
RE: Locating Hex-shaped Pin Holes
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Locating Hex-shaped Pin Holes
RE: Locating Hex-shaped Pin Holes
"Know the rules well, so you can break them effectively."
-Dalai Lama XIV
RE: Locating Hex-shaped Pin Holes
Are these accurate holes on a substantially less accurate pattern?
--
JHG
RE: Locating Hex-shaped Pin Holes
RE: Locating Hex-shaped Pin Holes
The top FCF controls the size, location, orientation and form.
http://www.dimcax.com/gdt_web/september-00.htm
RE: Locating Hex-shaped Pin Holes
RE: Locating Hex-shaped Pin Holes
"Know the rules well, so you can break them effectively."
-Dalai Lama XIV
RE: Locating Hex-shaped Pin Holes
Season
RE: Locating Hex-shaped Pin Holes
we do this all the time.
RE: Locating Hex-shaped Pin Holes
RE: Locating Hex-shaped Pin Holes
Certified Sr. GD&T Professional
RE: Locating Hex-shaped Pin Holes
unless you need to control the hex holes orientation - that's a whole new ball game.
but you said round pins fit into them, so gauge it with round pins!
RE: Locating Hex-shaped Pin Holes
Suggest You detail the hex-hole planform and edges carefully: these aspects may be structurally important.
Are internal hex corners rounded-off [radiused] to eliminate stress concentration of a sharp-entry corners that might initiate cracking under pin-interference-pressure?
Are entry and exit edges chamfered or rounded-off [radiused] to facilitate pin entry and eliminate sharp edges that might initiate cracking or chipping... especially at the hex corners?
These details could be added to a basic 'sharp-hex' profile as 'typical' details.
NOTE.
Stress guys hate 'random orientations of sharp entry features' [corners]: suggest the hexes have a common hex-orientation in either an [X-Y] or [polar] arrangement.
Regards, Wil Taylor
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o We believe to be true what we prefer to be true. [Unknown]
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