Compound Datums

[[Ni...]]

Good Morning,

I have an idea on how to create a compound datum in calypso when both datums are diameters. But I now have a compound datum between 2 planes and I am not sure how exactly to translate this into calypso.
Could someone help me with this?
I am looking to find True Position of Dim29 using datum F | A-C | B
Datums A-C is the one I am not sure on how to set it up in calypso.

Thank You,

compound A-C.png

[[Ma...]]

I would choose offset plane - take 2 points on base A and 1 point on base C with offset ( as they mentioned C1 point )

[[Ni...]]

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I found 2. Which one would be the correct one? Plane with offset(A-C 2) or offset plane(A-C 1)

plane with offset.PNGoffset plane.PNG

[[Ja...]]

AC-1 should be used.

[[Ni...]]

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Alright. How about the strategy? are only 3 points enough, 2 on lower plane and 1 on upper plane?
Or should I do polyline on both surfaces?

[[Ja...]]

I have never used offset plane so I dont know for sure but I think three points on datum -A- then clearance data then point on datum -C- (use datum target dimensions for this point). Try and watch for collision...

I dont know how if the datum target for -C- is a line or just a point. you can know this from side view of that print if it shows a specific height at which the datum target -C- is located. If not shown then it is a line for datum -C- target but I dont know how it all works still. Try or wait for someone else to respond...

[[Ma...]]

Because of A-C usage as secondary base, then only one axis is used ( A1 or a2 )

As Jayesh Patel mentioned choose A-C 1 ( second attach. )
Only 3 points can be edited for offset, but if you make 1st point on C base, then you can posibbly take unlimited points on A base.

I don't know exactly what comes first, but try first set offset in evaluation window, then get points ( you can recall them also )

[[Ni...]]

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I don't exactly understand what offset numbers I should be using and where does that number come from. does it come from my base alignment? am I supposed to find out how far datum C is from the base alignment on the X? Y? Z?
Youre also saying if I make one point on datum C surface, then I can do polyline on datum A? in the same strategy?

Sorry for all the questions but its my first time using offset plane and ive read other posts but I am still not sure how people come up with those offset numbers and where they came from.

[[Ma...]]

Sorry, but i am not at machine now.
But basicaly - datum A is origin, datum C has basic dimension on drawing ( imagine you put shelf on wall where left pin is much higher then on right )

Offset plane was discused on this forum recently

[[Ni...]]

This is what I did. Point 1 is on Datum C. Point 2 and 3 are down on Datum A.
Here are what happens when I put offset numbers FROM point 1 which I picked on datum C. which should be negative. I checked the distance between both planes and got 1.7980 which is why I put -1.7980 from datum C.
Last picture is what happens when I put the offset numbers as positives.
It seems to move the actual position of points 2 and 3 in the simulation when I add an offset.
I don't know how this would work as Datum A-C in the true position of the small diameters.

[[Ma...]]

Seems like 2nd try was correct - it should be positive.
But on drawing is datum A defined as one plane near to datum C - 3rd point is not on correct place.