Runout - Shaft with Notch
Runout - Shaft with Notch
(OP)
I have a cylinder shaft with a small flat notch on it roughly centered about the length. I am applying a total runout tolerance to the shaft.
In the drawing view, the shaft is layed out horizontally and the notch is shown on the top surface, while the bottom surface is shown as one continuous line.
How do I specify that the runout applies everywhere but the notch? Or is this implied? Do I need a FCF on both sides of the notch? From what I could find, ASME Y14.5-2009 doesn't talk about breaks in the surface where a runout is applied.





RE: Runout - Shaft with Notch
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at posting policies: http://eng-tips.com/market.cfm?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Runout - Shaft with Notch
If the face to face tolerance is more important than the centreing of the notches, you can apply a positional tolerance to the dimension.
RE: Runout - Shaft with Notch
Dave D.
www.qmsi.ca
RE: Runout - Shaft with Notch
RE: Runout - Shaft with Notch
Powerhound, GDTP T-0419
Production Manager
Inventor 2009
Mastercam X3
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II
RE: Runout - Shaft with Notch
Cylindricity combines roundness, straightness of an axis and straightness of a surface.
Dave D.
www.qmsi.ca
RE: Runout - Shaft with Notch
RE: Runout - Shaft with Notch
Dave D.
www.qmsi.ca
RE: Runout - Shaft with Notch
I'm applying runout to datum feature A (shaft), thus relating to datum axis A (shaft axis).
RE: Runout - Shaft with Notch
That being said, the 9.5.5 refers to figures 9-6 & 9-7 which are the same examples used in the 94 standard. We have the datum axis derived from 2 features and the circular runout is required on one of the features.
Your example is to itself and not 2 features. I know that the words in 9.5.5 say this may be legal but the example reflects something different. I, again, would reflect the OD with cylindricity since it is well understood.
Dave D.
www.qmsi.ca
RE: Runout - Shaft with Notch
I do agree that cylindricity would be better understood here.
As for my company using the 2009 standard, the drawings absolutely reflect that and our manufacturers are working with us as we progress into the GD&T world. Most of this is actually new for them as well.
RE: Runout - Shaft with Notch
I would NOT recommend the 2009 standard in my drawings at this time. It is WAY too complex and you would be better off using the 94 standard especially since everyone is new at GD&T.
I have been training in this subject for over 20 years and will not incorporate much of the 2009 standard changes into my basic GD&T seminar. In the Advanced seminar, I will get into degrees of freedom, calculating MMBs depending upon whether they are primary, secondary or tertiary, MMC application to profiles, etc. but it is heavy.
As I stated, go cylindricity and apply the same tolerance as you had in mind for the total runout.
If your company and your suppliers are new to GD&T, get some training and then find someone who would be your GD&T guru for ongoing consultation. Make sure that everyone in your plant who will be using GD&T receives the same training. The danger is that you could be putting something on a drawing that you may not understand and cost your company a lot of $$. On the other hand, one could end up with conflicts on the drawing and could lead to a part made to specification that may not function. BIG MESS!!!
Dave D.
www.qmsi.ca
RE: Runout - Shaft with Notch
I'm just the CAD guy though, so I don't have much input on what our company decides to do...but I see no reason for us not to adhere to the '09 standard.
RE: Runout - Shaft with Notch
RE: Runout - Shaft with Notch
I would suggest training to the 94 standard and then, maybe, in a couple of years converting to the 2009 standard. It is a complex standard relative to the older standards with some typos and other errors in the initial printing.
Dave D.
www.qmsi.ca
RE: Runout - Shaft with Notch
Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services