Max & Min Dimensions
Max & Min Dimensions
(OP)
Simple question... When is the use of MAX or MIN appropriate?
When would a dimension like .060 MAX be preferable over .060 +.000 / -.010?
Am I telling the machinist by applying a MAX dimension that don't care if the dimension is .000? 9000 ft for MIN? My guess is yes... But then why would anyone want to use these terms?
When would a dimension like .060 MAX be preferable over .060 +.000 / -.010?
Am I telling the machinist by applying a MAX dimension that don't care if the dimension is .000? 9000 ft for MIN? My guess is yes... But then why would anyone want to use these terms?





RE: Max & Min Dimensions
RE: Max & Min Dimensions
I have used the MAX dimension when I draw something that looks like an aluminium angle. I specify a radius of 12mmMAX. The minimum acceptable radius is zero, as you noted above. This allows the fabricator to use stock aluminium angle, if he has any lying around.
RE: Max & Min Dimensions
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: Max & Min Dimensions
Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services
www.infotechpr.net
RE: Max & Min Dimensions
So use carefully... And probably sparingly, in only a handful of situations. I like the thread depth use and the min radius sounds like a handy application for me.
Thanks.
RE: Max & Min Dimensions
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: Max & Min Dimensions
Chris
SolidWorks 09, CATIA V5
ctopher's home
SolidWorks Legion
RE: Max & Min Dimensions
Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services
www.infotechpr.net
RE: Max & Min Dimensions
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: Max & Min Dimensions
http:
Page 28: http
Chris
SolidWorks 09, CATIA V5
ctopher's home
SolidWorks Legion
RE: Max & Min Dimensions
"Wildfires are dangerous, hard to control, and economically catastrophic."
Ben Loosli
RE: Max & Min Dimensions
RE: Max & Min Dimensions
You bring up a major point of contention I've had with a customer I used to have to deal with. With the original print there was no specification on the radius yet you were getting good parts, then one day you got parts that didn't work yet they were manufactured using the same print. Wasn't there a huge uproar that originally blamed the manufacturer for the error since the print had "worked" in the past? The customer I dealt with had used certain vendors for years and when they went through a big cost savings crusade, they had things re-quoted and began to use different vendors. The result was a lot of bad parts made to print. The prints were not very good and the previous vendors had worked their way through the issues over the years and had figured out what the customer had wanted. The first knee jerk reaction was that the new vendors were morons because the prints were yielding good parts before the switch and it took an act of Congress to get them to see that the prints were the problem, not the vendors. The biggest issue was the misuse or non-use of GD&T.
Anyway, I don't mean to hijack the thread, I just wanted to know if the manufacturer originally got the blame for the non-functional parts.
Powerhound, GDTP T-0419
Production Manager
Inventor 2010
Mastercam X3
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II
RE: Max & Min Dimensions
I use a lot of max values for draft angles too. I don't care if the mold maker uses zero draft if they can get the part out of the mold. Usually, the mold maker will use very nearly all the draft I give them.
You definitely have to think through the consequences of all your dimensioning choices.
RE: Max & Min Dimensions
RE: Max & Min Dimensions
It was all internal to the parent corporation. I worked in the mold shop where we machined the molds for the glass plants to form the product.
We did a lot of fine finish polishing on the molds by hand and these blend radii where part of the hand process.
Once we understood the problem and had inspected the molds, a simple drawing change and instructions to polish guys and the issue was resolved.
"Wildfires are dangerous, hard to control, and economically catastrophic."
Ben Loosli
RE: Max & Min Dimensions
It defines the meaning of Max & Min and gives examples of when to use them.
The issue above where MBD gets involved is significant and has come up in other MBD related threads.
I think max/min has been discussed before too.
As to why to use them, it's to maximize the likelihood of "good parts" while ensuring function.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Max & Min Dimensions
Solid Edge V20
RE: Max & Min Dimensions
4X R.030 MIN TO 2X FULL R MAX
I was confused at first but I figured it out and plan to use it where appropriate in the future. One more exception to my dislike of MIN and MAX.
Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services
www.infotechpr.net
RE: Max & Min Dimensions
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
RE: Max & Min Dimensions
Is that so the shop can just use whatever punch they have that fits?
i.e. for a .500 wide slot the call-out could be:
R.03+.22/-0
Allowing them to punch with whatever fits?
V
RE: Max & Min Dimensions
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Max & Min Dimensions
Well, I'm thinking that calling out the max size is advisable when calling out the min, as he's done, while still not wanting to have a situation where the slot radii are produced beyond 'full R' (in other words, a hole at either end that exceeds the width of the slot).
But maybe I'm over thinking things.
RE: Max & Min Dimensions
That said, looking at Peters example again I'd have to question whether the 'MAX'on the end is really needed, though I suppose it balances the 'MIN' on the 2X .03.
It's one of those where I get the intent but wonder if it's more confusing than it's worth and if showing an 'Alternate Profile' may be better.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Max & Min Dimensions
Eh?
RE: Max & Min Dimensions
Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services
www.infotechpr.net
RE: Max & Min Dimensions
In the unlikely event you are concerned about it being bone shaped by a few thousandths then applying additional controls is appropriate.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Max & Min Dimensions
I use the examples in Y14.5 to define slots, I'm simply saying that if someone wanted to control the dogbone issue, a controlled radius would probably be a more simple way of doing it as opposed to a MIN/MAX callout.
RE: Max & Min Dimensions
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Max & Min Dimensions
Maybe I'm not familiar with the part where indicating only the MIN is OK because the MAX is already defined per the spec being that the feature is a slot.
RE: Max & Min Dimensions
Peters Note is trying to give to options. An essentially rectangular cutout with Minimum corner radii of .030. Or a conventional slot with R defined by the width. Given that the max R is limited by the width of the slot, I was questioning whether it was really needed to say 'MAX' at the end.
Frankly, this confusion is enough to convince me that using the note Pete put may not be a good idea.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Max & Min Dimensions
I do however use "MIN" and "MAX" on assembly and interface drawings. It is often beneficial to specify a min or max distance in relation to other components when you do not require a specific tolerance or when a tolerance is defined by the features of the detail parts and it is impossible to put the parts together in a fashion that requires a specific tolerance.
An example would be two plates held together with fasteners. The plates cannot be any closer together than .000" but it may be acceptable to have a .010" gap between them. In this case a tolerance of +.010 MAX would serve just fine.
David