hi Ravi you have to locate the holes from datum only if u are controling it from a non datum then u have to consider tol allowance for feature as well Thanks &...
I have a drawing where I am dimensioning a pattern of tapped holes Using a composite position control. I also want to specify a projected tolerance zone for...
... It should go with the level you want the projection to be measured. Also, it should be in the PLC and/or FRC. PLTZF and FRTZF are established by the PLC...
Hello, I am a cmm programmer/inspector. I feel I have a pretty good working knowledge of GD&T and I dive into the standard as needed. Usually I can understand...
I had been looking at section 1.3.1, but after posting here, I looked on cmmtalk and found a reference to section 5.10.1 which answered my questions nicely. I...
I have a rather long part that I need a couple of holes to have a true positon callout of 3.5, both only in the fore/aft direction and only in the positive...
I'm not sure I understand the intent here. Why do you want to use a unilateral tolerance? Why not just move the nominal location of the holes by 1.75 in the...
I don't want to move the nominal because if a new tool is ever made, I would like it cut to the exact same model. If I change the nominal, I run the risk of...
Unless I am much mistaken, TruePosition by definition means a tolerance zone *around* the specified dimension. If you want a unilateral tolerance for one axis...
true-position callout is a circular/spherical tolerance zone as i understand it,so there is no way to specify a unilateral tolerance zone using a true-position...
I have been handed a legacy drawing to update to the current GD&T standard. The part is a shaft with a curvic coupling at one end. The pitch plane is called...
Pardon my ignorance, but I am not familiar with the term, "curvic," or "curvic coupling," and your simple drawing and explanation is a little too "simple" for...
Sorry about the earlier post. A curvic coupling is a splined face that can be to connect shafts. I have uploaded 2 files. In figure one the curvics are...
So, if I understand this arrangement correctly, it is essentially mating to "cones" together (that are splined to carry a torsional load), correct? That would...
A curvic is akin to a spline only its on a plane. They are most common on the end of a cylinder. They have teeth and and mesh with their expected opposite on...
Sorry. Tool late for this info. Already covered ground :). Don ... From: Donald Coon To: Y14-5_User_Group@yahoogroups.com Sent: Thursday, March 09, 2006 7:01...
Don, thanks for the explanation. If the physical interaction of this type of item does not inherently create an axis, then runout would not be a correct...
Mark, You mentioned earlier that a cone constrains "5 degrees of freedom" I agree (it constrains all except the rotation about the axis). A curvic constrains...
Paul, Right you are regarding its ability to stop all 6 degrees of freedom. In my mind I was seeing that it was axisymmetric and therefore my mind "didn't ...
All of our curvic applications are axial tranfer as you suspected. No bending around corners. For us its action along a shaft(think rotor mast or tail rotor...
Who wants to wade in on whether a curvic can have a virtual condition? I'm supposing that to work properly the contacting surfaces of a curvic have to be...
Ooooo, you are sick, man! Sick, sick, sick! ;-) Ok, as soon as you can tell me how "big" the curvic can be (or small), then I'll tell you what its virtual...
I may a little late in this discussion, and lurking is killing me.. Another way to describe a curvic coupling is visualize a spline manufactured on the end of...
I am curious about the real effects of applying (M) for a threaded feature in a TOP combined or not with a projected tolerance zone (P)... Can somebody help me...
My understanding is that anytime GD&T is applied to a thread, it is the pitch diameter that is being controlled, unless otherwise specified. Depending on the...
Yes thanks, this is what I was thinking... I was using (M) but without really giving it a careful thought. Plus we do inspect our threads at MINOR DIA (noted...
Without the modifier "M" it will be RFS which is more unreal for pitch dia., major dia. or minor dia. The "M" does allow the design of functional gaging....
"we always done it like that" (for the past 50 years!) doesn't make it correct. didn't have gd&t 50 years ago. i agree with wes and IMHO RFS would make more...
