Angle Less than One Degree.
Angle Less than One Degree.
(OP)
Looking at an Inch print using ASME Y14.5-1994 specifying an angle of .50 degrees.
Does one use a leading zero or not on this dimension? 0.5 degrees or .5 degrees
Thanks
Does one use a leading zero or not on this dimension? 0.5 degrees or .5 degrees
Thanks
RE: Angle Less than One Degree.
This wording was not in the 1994 standard that I am aware of.
If you look at figure 2-2 in the 94 standard, it does show a tolerance of -0.2 degrees with a leading zero.
RE: Angle Less than One Degree.
Number of trailing zeros depends on a tolerance for this angular dimension. Generally saying - both dimension and tolerance must have the same number of digits after decimal point.
RE: Angle Less than One Degree.
Thanks
RE: Angle Less than One Degree.
RE: Angle Less than One Degree.
RE: Angle Less than One Degree.
Mike Halloran
Pembroke Pines, FL, USA
RE: Angle Less than One Degree.
This looks really close to .35+/-.15.
So we usually look to the next standard if the Current one does not answer our questions.
Thanks again for all the feedback
RE: Angle Less than One Degree.
0deg35' +/- 0deg15'
RE: Angle Less than One Degree.
Does Y14.5-2009 (paras. 1.5.5 & 2.3.3) really show the angle using mixed unit symbols? (deg and '), as opposed to 0°35' ±0°15' ?
RE: Angle Less than One Degree.
RE: Angle Less than One Degree.
http://www.tipmaster.com/includes/charentities.cfm
You can also use the standard Alt key method;
Alt 0176 = °
Alt 0177 = ±
RE: Angle Less than One Degree.
What about the fact that a directly toleranced angle is very likely ambiguous and/or not providing the control that the part's function requires? If the considered feature is a planar surface then there is no tolerance zone for such a spec other than 4 lines drawn on a 2D cross-section of the feature that define min & max angles. If the considered feature is cylindrical then what is the controlled feature component and what is it controlled relative to?
For drafted features all the same issues apply. We've all seen direct tolerances applied to draft angles, but "relative to what measurable element/reference frame?" is the unanswered part of those specs.
Since this is a GD&T forum it seems appropriate to bring up the fact that the directly toleranced angle being discussed should be replaced with a basic angle from a plane or axis of a datum reference frame that is included as part of a position or profile call-out... Yes? No?
Should I have started a new thread?
RE: Angle Less than One Degree.
Whether to use GD&T is a separate discussion.
One other extraneous point that's a little closer to the core of the discussion is that it will almost certainly be necessary to include a synthesized view with the angle exaggerated, in order to make any sense of the direction of a small angle.
Mike Halloran
Pembroke Pines, FL, USA
RE: Angle Less than One Degree.
I think that's along the same lines as your comment, so yes I agree!
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
RE: Angle Less than One Degree.
I made the drawing more simple just to show the feature in question. I see how a profile of surface could be used instead of of a directly dimensioned angle with a +/- dimenion. The r2.0 is there to show the cross section go through a circular area of the part
Thanks
RE: Angle Less than One Degree.
Since you are using The Y14.5 standard, may I suggest you relocate your datum feature symbol B. The standard states that datum feature symbols identify physical features and should not be applied to center lines, planes, or axes.
The problem for manufacturing/inspection is how do they know which feature the center line/plane is referring to.
I would also consider Mike Halloran's point - how do they know which way the angle goes? Is it tapered up, or down? You may have to exaggerate the angle or clarify with a note.
RE: Angle Less than One Degree.
The angle direction should be implied. This part comes off a mold and for this to happen the draft can only be in one direction because the if it was the other way the tool we would crash.
Good points and also thanks for the feedback.
RE: Angle Less than One Degree.
Peter Stockhausen ://www.lin kedin.com/ profile/vi ew?id=3006 4526&t rk=tab_pro
Senior Design Analyst (Checker)
Infotech Aerospace Services
www.infotechpr.net
http
RE: Angle Less than One Degree.
If you have access to ASME Y14.8-2009: "Castings, Forgings, and Molded Parts", section 3.6 specifies different methods of assigning draft angles. Maybe you can find something interesting for you.
'Directly toleranced angle' method is not among them mainly because of all the reasons that Dean and J-P highlighted.
RE: Angle Less than One Degree.
I'm sure I will rightfully hear about it if I'm incorrect with the assertions I'm making in the file
Dean
www.d3w-engineering.com
RE: Angle Less than One Degree.
I'm not disagreeing; I'm just thinking out loud... what if someone tries to arbitrarily call one side of the wedge an implied datum and then tries to scrunch all the angular tolerance onto the other side of the wedge?
I'm not saying that's wise, because a datum can only be made from high-point contact and thus we can't know the form of that "datum" side. But is an angle with a ±tolerance really meant to control form?
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
RE: Angle Less than One Degree.
I think you could say that someone may try to scrunch all the angular tolerance to one feature & use the other as a reference surface. I don't think they have any standard to back up what they're doing, so maybe that's the same situation as splitting the tolerance equally on both sides
Since we have no standard to define a tolerance zone for directly toleranced angles I don't think form can be considered controlled this way... I can imaging features which both have horrible form, but with best-fit lines (one for each feature) at a given cross-section having an acceptable angle between them, I think a supplier could declare the feature to be in spec.
I think it's quote odd, in a bad sort of way, that so many drawings have default tolerance blocks with +/- angle tolerances included. These tolerances don't really mean anything, er, I mean, they may mean several things.
Dean
www.d3w-engineering.com
RE: Angle Less than One Degree.
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
RE: Angle Less than One Degree.
RE: Angle Less than One Degree.
DeanD3W, you make a valid point, but I wonder if you're over stating it a little.
Certainly for critical stuff with angles I tend to use profile and encourage others to do so. However, I'm hesitant to completely throw out +- dims on angles but maybe I'm pandering to the 'GD&T is too complex/costs money' crowd.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?