Old problem and again I struggle...CAD, Cyl shaped part, alignment

I have a part that basically looks like a Gauge Pin with a hole drilled thru it (90 perp to the longitudinal axis of the cyl).

I am having a very difficult time trying to get this thing aligned using CAD. I have tried 3 points on one of the flat ends, then 2 points along the length, and a single point on "top" about halfway between the thru hole and the nearest end.

Get Iterative Alignment error.

If I dont use iterative alignment, and instead use cir at one end, a cir at the other end, and the thru hole, I can't get the features to "stick" to the CAD.

I've got the part laying on its side inside a R&R AVP 11-20 V-shaped standoff, with the thru hold pointing up, and the length of the part inline with the machine's X-axis.

Running PCDMIS 2013MR1

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NinjaBadger over 10 years ago

Datums. Align to the datums.

OR, measure the OD as a cylinder.
Measure that ID as a cylinder
Measure a POINT on one end.

Level to OD cylinder
Rotate to ID cylinder
Origin to OD Cylinder (2 axis) and point on end

6 DOF locked.

If that ID cylinder isn't square to a rotate axis, so what? You MUST KNOW what it's angle is to the cad axis, you do the LEVEL, ROTATE, ORIGIN, ORIGIN, ORIGIN, then ROTATE ABOUT using the angle it is off 'square', then do origin (axis) OFFSETS if needed.

Looks pretty simple to me really.

Everything is when you know how though isn't it?

A couple of things - it doesn't look like the CAD co-ord system is as you've got it on the CMM

Use Opeation>Graphics Display Window>Transform to get it to match how you've got it on the machine

Now..

Change workplane to xplus or minus
Create the OD cyl on the CAD (Level in xplus or minus depending on the vector of the cylinder, and origin in Y and Z)
Create the ID cylinder on the CAD, and rotate to ZPLUS about X
Create a point on either end face (depending on the drawing datums) and origin in X (unless the drawing has the datum coming from the through hole, in which case Origin X in the ID cyl

Now run the program and measure the features in the right order and direction etc.
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NinjaBadger over 10 years ago

Datums. Align to the datums.

OR, measure the OD as a cylinder.
Measure that ID as a cylinder
Measure a POINT on one end.

Level to OD cylinder
Rotate to ID cylinder
Origin to OD Cylinder (2 axis) and point on end

6 DOF locked.

If that ID cylinder isn't square to a rotate axis, so what? You MUST KNOW what it's angle is to the cad axis, you do the LEVEL, ROTATE, ORIGIN, ORIGIN, ORIGIN, then ROTATE ABOUT using the angle it is off 'square', then do origin (axis) OFFSETS if needed.

Looks pretty simple to me really.

Everything is when you know how though isn't it?

A couple of things - it doesn't look like the CAD co-ord system is as you've got it on the CMM

Use Opeation>Graphics Display Window>Transform to get it to match how you've got it on the machine

Now..

Change workplane to xplus or minus
Create the OD cyl on the CAD (Level in xplus or minus depending on the vector of the cylinder, and origin in Y and Z)
Create the ID cylinder on the CAD, and rotate to ZPLUS about X
Create a point on either end face (depending on the drawing datums) and origin in X (unless the drawing has the datum coming from the through hole, in which case Origin X in the ID cyl

Now run the program and measure the features in the right order and direction etc.
Cancel
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