Changing Axis on CAD Model

[Underspec]

I know it's been said before. How do you change the Axis on the CAD model again, so that you don't have to setup the part to match the CAD? I never really played around with this before.

[Cumofo]

EDIT~
Preferences~
set up~
CAD

Then you can mess with the model in real time

or if your clever, do it befor you import the model.

!
1) choose your alignment features offline style.
2) Start the program, and then measure them manually.
3) you should level ASAP, then probe the rest of the features.

-Gabriel

[Bill **********]

Actually you don't EVER have to change the axis on the CAD model. Just add rotations in your alignment to make your CMM think its running the same way as the CAD axis. I have never change the axis of a CAD file in 15 years of CMM programming. A +90 degree rotation about the Y points Z ahead and X down, a -90 degree rotation about Y points X up and Z toward you etc.

[Paul Sarrach]

I know it's been said before. How do you change the Axis on the CAD model again, so that you don't have to setup the part to match the CAD? I never really played around with this before.

Question. If you are going to take the time to change the Axis on the CAD, why not just do in the setup with the CAD equals machine?

exactly what do you mean, part to match the CAD?

[DrBudman]

Actually you don't EVER have to change the axis on the CAD model. Just add rotations in your alignment to make your CMM think its running the same way as the CAD axis. I have never change the axis of a CAD file in 15 years of CMM programming. A +90 degree rotation about the Y points Z ahead and X down, a -90 degree rotation about Y points X up and Z toward you etc.

Thats the way I do it also......

[rebeldude]

I just let it think it is in those axises on the cad model. It works fine. Just make sure you load it the same every time or any angle changes in the program will be wrong. Otherwords, if you program offline to the cad, when you do the manual alignment it will pick it up as such.

[John Riggins]

I know it's been said before. How do you change the Axis on the CAD model again, so that you don't have to setup the part to match the CAD? I never really played around with this before.

I think what you are asking is how to change the trihedron to match what you have setup on the granite. For example: you look at what the trihedron shows (Z+ pointing to say Y+) and you want the trihedron to match your setup.

Here is what I do:

F5 (gets you to "Setup Options)

Click on the "Part/Machine" tab

You will see dialogue that says: Cad "X+" axis equals which machine axis?
And then some pull-down menus to select "X+, Y+, Z+, X-, etc.

Change each one until they match your setup on the granite.

Then click "Apply"

Then Click "OK"

Now, I have found it beneficial to first pick points or a plane on the Cad to establish your Leveling Plane (or some other feature to level to). And then immediately, before doing any other Alignment steps, level and X,Y,Z Origin on the plane (or whatever feature).

This works for me.

Email me if you want more help.

[BOB PARSONS]

CAD AXIS

THE METHOD JOHN JUST DESCRIBED IS HOW I LEARNED IT FROM B&S.

[Bill **********]

Why go through all of that hastle when all you need to do is add rotations to your Alignment. You can set the part/gage/fixture whatever up any dierction that you want. NONE of the CAD axis directions need to match the machine axis directions. We'll fix that in a minute.

Here is the trick. Hold out your CMM guy Right Hand Rule crippled hand. +X points away from you, +Y points toward your left and +Z points up. Now reach over with your left hand and grab your right hand thumb with the thumb of the left pointed toward your palm of the right hand. Rotations in the direction of your left hand fingers are positive rotations, opposite the direction of the left hand fingers are negative rotations. Now grab your +X index finger with your left hand thumb pointed toward your right palm. Again rotations in the direction of your left hand finger are positive rotations and opposite the directions of your left hand fingers are negative rotations. Now grab your +Y middle finger left hand thumb pointed toward the right hand palm, rotations in the direction of your left hand fingers are positive and the opposite are negative.

If you look at the CAD before doing any alignment it will show you the CAD axis directions. Pick up a 3-2-1 alignment on the fixture Jig corner and create an alignment. I typically initially set +X the long directions and +Y the short direction on the gage with +Z up. Once you established this alignment you can now add rotations to it to get the real world part situated into the CAD axis system. If the CAD +X is the short direction of the gage simply rotate 90 degrees + or - about the Z+ to point it in the proper direction. Sometimes you will need to do two rotations to get it all situated correctly, but this is a lot faster and easier than chasing design guys around trying to get them to move your CAD. The other problem with moving CAD and changing axis directions is that your layout results are NO LONGER in Car Body Coordinates. With this method everything relates right back to the customers CAD model.

If anyone needs some more help with this feel free to drop me an email.

Bill

[John Riggins]

Why go through all of that hastle when all you need to do is add rotations to your Alignment. You can set the part/gage/fixture whatever up any dierction that you want. NONE of the CAD axis directions need to match the machine axis directions.

Question Bill,

Does the Probe animation match the real world using this method?

[Bill **********]

John,

The probe animation works using this method everytime. In fact you will know immediately if your rotations are correct simply by looking at the probe in the CAD window.

Bill

[John Riggins]

Bill,

I just tried the method you spelled out and yes, it does work just the same as what I do.

The method I use is a bit faster for me, but I am sure thats only because thats what I figgured out how to do (self-taught) and it is second nature to me as I am sure what you use is second nature to you.

Whatever works. If it gets the job done and gets accurate results thats what counts.

Thanks,

John

[Paul Sarrach]

I agree with John, I have stated it time and time again about this subject. It takes seconds to align part to machine. And the best thing about is the Probe animation matching what you see in the graphic screen. That is the 1st thing I do after I import my CAD. drop down a couple of menus look at part change the x y z axis, never have to worry if you rotated incorrectly, is there gonna be a crash. Not saying your way is wrong, just that the way John and I do it, has many benifits and is not a hasle, having to think about all the rotations compared to looking at the part and filling in the 3 axis's seem to be more effiencent

[Bill **********]

Back in the day Pcdmis didn't have the ability to click and change axis directions so I've been doing it this way for a very long time. As you said, whatever works for you is fine. I just can't see chasing around after Design guys to change axis directions in customer CAD.

Bill

[rangerboat72]

We also use the Cad to Part option...

We also use the Cad to Part option, actually our customers prefer us to use this method so we are not altering the cad coordinates (In-Car-Position) to reflect our CMM coordinate system... Much simpler once you familiarize yourself with it...