@bstanford:
No, that flatness feature control frame does not control location of the surface feature A. It is used to qualify datum feature A. Without it, surface feature A can be of any shapes.
@Op:
Bottom face is the primary feature for datum A.
Your secondary datum feature B can be attached to dimension of 2x width of the slot.
Your tertiary datum feature C can be attached to distance between ends (inner or outer) of the slots.
Your datum feature A controls 3 DOFs (degree of freedoms). You can use width of 2 slots together as secondary that controls 4th and 5th DOFs which is rotation and translation up and down. You will need one more feature to control 6th DOF so that you plate does not move side to side horizontally...
Hi, Garland23:
I checked Figure 6-30 (ASME Y14.5-2029). Datum feature "C" is a primary datum for thread M42 x 1.5 - 6g.
Primary datum feature must stand alone. It can't be "qualified" by secondary or tertiary datum features.
Yes, it is possible for a primary datum feature to be related back...
Feature "D" is too small to qualify for a primary datum. "A" is a primary datum feature not because of character "A" but rather the precedence of A/B/C in the feature control frames.
Datum feature "A" is a primary one according to the feature control frame on your prints. You don't want to make it parallel to datum feature "D". It should be the other way around.
Why do you need to "import the equations.txt file from Part1 into the assembly"? Your equations in your assembly can reference any variables or feature dimensions in your parts so long as they are loaded to memory.
Surface of profiles with datum controls shape, size and orientation, while surface of profiles without datum only controls shape and size. The feature with this feature control frame is free to move in space of your coordinate system.
Thanks, 3DDave! But, if I use a profile tolerance of [1000 (U) 0], I'll have to inspect both USL (upper specification limit) and LSL (lower specification limit). I want to inspect USL only. How do I nullify this LSL?
Yes. It is derived from another feature in the assembly. Center line of this feature is coincident with centerlines of many other features. That is why 26 MAX. is no good. Sadly, there is no GD&T equivalent to 26 MAX.
No, I don't have a control for the MIN. It can be as small as "zero".
My issue with dimension 26 MAX. is that there are a lot of center lines. It is not clear which center line this dimension is associated with.
I can't do that as I don't care how small this dimension is. I just want to control this maximum dimension.
This dimension must be < = 26.
Basically, I am asking what is equivalent to 26 MAX. using GD&T feature control frame.
I have a feature size of a block. I need to control distance from end of the block to a datum "A". How do I use profile of surface FCF to control max. distance to the datum?
Your parts (part 1 and 2) have no relationship. Why do you want to force a relationship? What you are after is revision record of their parent assembly.
Putting in more intelligent characters into part no. causes redundances. You may want to read this technical research report...
Well, each feature shall be toleranced per ASME Y14.5-2018 section 4.1 (a).
Also, direct tolerancing on the dimension is NOT exclusively used on FOS dimensions.
4.1 FUNDAMENTAL RULES
Dimensioning and tolerancing shall clearly define engineering
intent and shall conform to the following:
(a)...