Align to 2 circles that are not in the same plane.

[Jan d.]

This is embarrasing: I can not get PC-DMIS to align properly to a line that I construct through 2 circles! I feel so stupid but I just can't get it to work.

Here is the situation: I measure a flat plane and I level to it. I am sure that works. Then I measure 1 circle (which is NOT in that plane), and I move the X,Y origin to it. That works too!

But here is the problem: now I measure a second circle. It is neither in the plane of the level plane, nor at the same level as the first circle. I create a line per the following code:

LIN2       =FEAT/LINE,RECT,UNBND
            THEO/-1.8375,-2.195,-0.4525,0,0,-1
            ACTL/-1.83772,-2.19522,-0.45218,0.1429261,-0.1203922,-0.9823838
            CONSTR/LINE,MID,DATUM -J- SH4 C1,DATUM -K- SH4 B3

Whatever I do, I can't get this to work properly. My suspicion is that the line is 3D or something. Anyway, what I want to do is to project the circles into the plane and then construct a line.

I can remember that this question came up before, but the search does not get me the result.


Any suggestions?



Thanks, Jan.

[Wes Cisco]

This is embarrasing: I can not get PC-DMIS to align properly to a line that I construct through 2 circles! I feel so stupid but I just can't get it to work.

Here is the situation: I measure a flat plane and I level to it. I am sure that works. Then I measure 1 circle (which is NOT in that plane), and I move the X,Y origin to it. That works too!

But here is the problem: now I measure a second circle. It is neither in the plane of the level plane, nor at the same level as the first circle. I create a line per the following code:

LIN2       =FEAT/LINE,RECT,UNBND
            THEO/-1.8375,-2.195,-0.4525,0,0,-1
            ACTL/-1.83772,-2.19522,-0.45218,0.1429261,-0.1203922,-0.9823838
            CONSTR/LINE,[COLOR=Red]MID[/COLOR],DATUM -J- SH4 C1,DATUM -K- SH4 B3

Whatever I do, I can't get this to work properly. My suspicion is that the line is 3D or something. Anyway, what I want to do is to project the circles into the plane and then construct a line.

I can remember that this question came up before, but the search does not get me the result.


Any suggestions?



Thanks, Jan.

It is still terribly early, but I think the "MID" is your problem. If you want to project to the plane then level to your plane, make sure you are in the proper workplane, measure each circle then consturct a 2D line. That should do it. HTH

[Matthew D. Hoedeman]

#1) BOTH circles will need surface sample hits to establish a totally 3-D location (you will have to do manual-mode auto feature circle for this)
#2) The constructed line NEEDS to be 3-D or Pcdmis will try to force it into whatever workplane you are using.

[Jan d.]

It is still terribly early, but I think the "MID" is your problem. If you want to project to the plane then level to your plane, make sure you are in the proper workplane, measure each circle then consturct a 2D line. That should do it. HTH

Got it! Works fine.


Thanks Wes, Jan.