Easy way to rotate an alignment! Please help.

[Josh Seiden]

I've been programming Calypso for a decade. I'm now using PC-DMIS with 2013 software. Big difference, but I can figure it out if someone could tell me how to rotate an alignment. Something simple, for instance:

Datum A is Z PLUS
Datum B is X/Y zero.
Rotate to Datum C +5.0000" in X, -5.0000" in Y.

I'm on the alignment screen. How do I rotate my alignment for Datum C. Thank you.

Josh

[Darrollh]

If it’s what I’m thinking, make datum C your origin.

[Josh Seiden]

A is primary (Z plane), B is secondary (diameter), and C is tertiary (diameter). B is the XY origin. I need to simply add C to my base alignment without changing B as the XY origin.

[JacobCheverie]

Can you attach a snippet of your print? I would assume you’d want to construct a line from B to C and rotate to the line about Z+.

[Josh Seiden]

Thanks for responding. I just threw together this example. Imagine this is a square block on the table. B is a diameter and the origin of the part. There's also a diameter C that's the tertiary datum. I need to know how to rotate to C, while still keeping B as the XY origin.

[Douglas]

Is datum c a feature? What type
Sounds like you want

Level z+ to datum a
Rotate xplus to datum c feature about z+
Offset rotation angle 45°
Origin x from datum b
Origin y from datum b
Origin z from datum a

[Josh Seiden]

Thanks for responding. You are telling me what I need. Since this was an example. What if C was not 45 degrees? What if it was X+ 2.5500" and Y- 1.7500"? Do I have to rotate by degrees or can I rotate by the print dimensions? Keep in mind that I want B to be the XY origin.

[Douglas]

I guess it depends on other stuff, if datum c was the only feature I'd probably just trig the angle and rotate by that....

Edit: this stuff depends exactly how the print shows it

If it is one of 2 drill holes or something straddling the x axis I'd probe both holes, construct s midpoint and rotate to that

[Josh Seiden]

Thank you. I don't want to create a midpoint since it'd throw off my nominals. Is it possible to put in the datum C coordinates without calculating an angle?

[Douglas]

Im assuming because x and y values of datum c are equal it is a feature at 45° from x axis if I'm picking up what you're laying down that is

Edit: -45 from x axis I suppose

[Douglas]

I ran calypso before pcdmis the last 5 years... sorta get where you're at it is an adjustment for sure

Fundamentals don't change,,, well except for the whole tip2 and tip4 star naming convention, hexagon had to be different

But you fundamentally know what the machine can do and what you want it to do just new code to do it

[JacobCheverie]

Josh,

Measure datum feature A. Create an alignment, select the plane, Level Z+, end alignment.
Measure datum feature B. Don’t origin yet.
Measure datum feature C.
Construct a line between B and C.
Create an alignment, select the line, Rotate X/Y (your choice) about Z+. Now set X and Y origin on datum B and set Z origin on datum A.

Some members of this forum will advocate creating a third, final, and complete alignment that has all the preceding steps; namely Level A, Rotate B-C line, Origin X&Y on B and Z on A.

Hope this answers your question. Good luck, it’s interesting to go from Calypso to PC-DMIS. I program both regularly and they both are certainly unique.

[Josh Seiden]

Thank you. This sounds easy enough. Do you ever rotate by the print dimensions? Maybe this isn't a PC-DMIS thing.

[Douglas]

Wouldn't that put the tertiary feature on the axis selected to rotate, rotate X+ to the constructed line gives that datum c feature y value 0 not 5,-5

[Douglas]

Oh... get used to frequently saving progress. I crash pcdmis a fair bit and most will agree

[JacobCheverie]

Always keep one finger on CTRL and another on S, quick save every 3 seconds. I’m pretty sure they told me that at level 1 training

[Douglas]

Every other feature or so here

[Douglas]

Yesterday a crash worked in my favor, half hour into the afternoon it crashed but made me reconsider the measurement plan and probably saved me time in the end

[neil.challinor]

I think what Josh Seiden is looking for when he asks

Thanks for responding. You are telling me what I need. Since this was an example. What if C was not 45 degrees? What if it was X+ 2.5500" and Y- 1.7500"? Do I have to rotate by degrees or can I rotate by the print dimensions? Keep in mind that I want B to be the XY origin.

Is a constructed, offset line. That would allow him to fix the offset between his two holes rather than rotating by the theoretical angle. As other people have stated, it all depends on how it's shown on the print.

[NinjaBadger]

Offset lines can (will) often cause errors in and ABC type alignment. Unless the pitch of the holes is perfect then if you use an offset line then report the Polar angle of Datum C it will have and angular deviation.

The only safe solution really is to trig out the angle.

[neil.challinor]

It depends what you're trying to do. If you have two holes and the distances between them in both axes are boxed on the drawing (T.E.D) then, yes, trig out the angle and rotate by that. If only one distance is boxed use an offset line to "fix" the distance in that one axis.