I'm currently working on drawings that require dual dimensioning by the customer. The formats for metric and imperial unit dimensioning and tolerancing are different (i.e., leading zeros vs. trailing zeroes, unequally disposed tolerance). Is there a way I can set up the dual dimensioning such...
I'm doing a capability study on the flatness of a group of parts. The IDI indicated the Weibull as the best plot use. The LSL on flatness is always 0. What I noticed is if I enter a 0 for the LSL I get a Ppk of 1.08. If I leave the LSL blank I get a Ppk of 2.72. Why this difference and which one...
We are currently dealing with an issue where I work and it is regarding the degrees of freedom constrained by a toroidal datum feature used as primary. To be specific, it's not an entire torus, it's just about 7 degrees of the subsidiary radius but all 360 degrees of the main radius. It seems to...
Does this make any practical sense? I just saw a figure in Y14.43-2011 (Fig. B-11) with this and I'm trying to wrap my head around whether it's actually valid and what could be the use of it. I didnt' find any explicit prohibition of it but that shouldn't automatically mean that it can be done...
On figure 4-45 of the 2009 standard: if B were made the primary datum, would that eliminate the need for the customized DRF? I know the inspection result will be different than having A as primary so there's no need to go there.
Thanks,
John Acosta, GDTP S-0731
Engineering Technician
Inventor...
Hi guys,
Is there a difference in interpretation between the two scenarios?
John Acosta, GDTP S-0731
Engineering Technician
Inventor 2013
Mastercam X6
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II
I need a little help here.
How would I go about ensuring that the flat on the internal D-hole is oriented to the gear tooth pattern? We are referencing an AGMA spec to dictate the geometry. I don't know the number of the spec. My assumption is that the tooth geometry--and tolerancing--is...
Hi all,
We are currently in the process of specifying some controls for a steel ring that we want to make and I have a question about the direction we are going. The part is basically a thin ring--about 4mm thick or so--that will be machined and heat treated. We know that the part will...
Hey folks,
Another question has come up. I found another thread on this subject but didn't find a definitive answer in it. I don't find direct support for parallelism on a per unit basis. This seems to be a legitimate extension of principle but I'd like to get others opinions or maybe point...
Hey guys,
Another question:
Do you see anything wrong or questionable about the attached drawing? Assume all the dimensions are there, it's just teh profile related to the DRF that I'm asking about.
Thanks,
Powerhound, GDTP S-0731
Engineering Technician
Inventor 2010
Mastercam X6
Smartcam...
Since all geometric tolerances apply in free state condition by default what is the purpose of the circle F in Fig. 6-53? I have always been under the impression that a circle F modifier is only used when there is a restraint note on the print and the specified feature is to be check...
Here's a hand drawn sketch of a question I got a couple of months ago. I've been meaning to post it and just now remembered. Being that the only case of a projected tolerance zone of any kind in the 94 standard is shown as a special case of position I wonder if it's a stretch to use the same...
Hi everyone,
We have a dilemma here and I need to either be corrected or backed up. Attached is a simplified example of what we're dealing with. My stance is that since datum B is an axis, there is really no orientation refinement possible, thus the datum B reference should be removed from...
Another question guys:
I am currently dealing with another spline type issue but it's a different part. The spline is the female part. The standard invoked is 1994.
The 9 spline center of the part has the minor diameter called out as a datum and it is a toleranced dimension. The minor...
Hi guys,
I need to specify a spline as a datum on a part that we are having built. The spline has a tooth missing so that it can only be put on one way. We also have a spline table on the print that specifies the spline data. How can I call out the spline geometry, not the pitch diameter, as...
Hi guys,
I've put together a list of fundamental GD&T concepts for your review. This list is based on frequent errors I see when checking prints. I thought I would put them all in one place and make the list available to the designers and engineers here. I want to submit it for peer review...
I'd like to get everyones take on an issue. If a machine shop gets a print with no GD&T on it as well as no reference to any dimensioning standard, how much responsibility does a machine shop have to catch any unspecified tolerances. For example: a 3 foot long rail with various slots and holes...
What are the opinions of those that frequent this board in regards to the qualifications required for one to be able to teach GD&T? Currently it seems that there is no requirement, but to prohibit someone from teaching based on the fact that they have no ASME certification seems extreme. My...
This thread was started so as not to hijack the "Symmetrical" thread any more than it already has been.
Regarding ringmans reference to FIG 5-21 in the standard, I have no idea what you are trying to convey about rectangular tolerance zones by using this example. This is a perfect example of...
Hi all,
Are there any quartz guys out there? I've been in it for about 5 years now and it seems to be a fairly small field in my part of the country.
Powerhound
Production Supervisor
Inventor 2008
Mastercam X2
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II
