Probing Horizontal Cylinder

[[Ty...]]

Good morning all,

I have a program checking a shaft that is horizontal in a V-Block. I am trying to program this cylinder using a 2 section circle path.
The first circle path probes just fine, but then the probe tries to go underneath the shaft following the diameter to start the second section. Obviously the shaft runs into the part and "crashes."

I feel like there is a box somewhere that needs to be clicked or un-clicked or some other simple solution.

Screenshot 2024-02-05 112419.pngScreenshot 2024-02-05 112801.pngScreenshot 2024-02-05 112820.png

[[Ju...]]

Is there another clearance plane between the two paths? Also, double check your retract distance under Clearance Data for that feature.

If not, you may want to have the second path start on the same side of the cylinder as the end of the first path and scan the opposite direction. I usually delete the Circle Path (2 sections) and replace it with two individual circle paths to do this.

[[DW...]]

Are you using a line in your base alignment to clock rotation?

[[Ty...]]

I am using a 3d like for the Rotation in space, and a plane for the Planar Rotation.

[[Ma...]]

Basically what's happening is the machine is trying to take the shortest path to the start of the next circle. Because you scanned 180 degrees and it over-traveled a little bit the shortest path is under the part. Set your scans to start and end a degree or two above the center of the circle and it will work fine. You can also add clearance point(s) between the circles if you absolutely want to get 180 degree or more scans.

[[Ma...]]

Programming as separate circles instead of a cylinder will also work. Programming individual circles inside the cylinder strategy will work too if the scans are in opposite directions, ie it starts circle 2 on the same side that circle 1 ended on.

[[DW...]]

Please sign in to view this quote.

I would advise against that. If you probe the points of the line in the incorrect order, the spatial axis will be inverted. Perhaps use a plane for spatial rotation (you can use the CMM granite, or the plane on top of your V block). The spatial rotation axis should then be +Z. Double check your scan paths.

Please sign in to view this quote.

This shouldn't be the case. If the scan paths are set to start at 90° and go -180°, and the clearance group is +Z, it should scan circle path one from 90° to -180°, retract, come back over the top of the cylinder to begin probing the second scan path at 90° from +Z.

[[Ma...]]

Add clearance data - sometimes it will decide that shorter path is underneath

[[Ri...]]

Calypso travels via the shortest path. Due to uncertainty error, even though you may tell it to stop at 180° it might go slightly beyond that, and then at that point it is technically a shorter path to attempt to go under to get back to 0°.

There are multiple ways to overcome this:

1) Reduce your scan range to say 179°.

2) Break up your two scan paths, and add a Clearance Data between them.

3) Break up your two scan paths, and reverse the second path (Start at 180° and travel -180°).

[[Ja...]]

From the image posted, it looks like you do not have a CAD model for the part. I am wondering if that might be problem why the scan is going straight from end point of first path to end point of second path and crashing instead of taking a spiral path around the the part or another reason might be just because the stylus system is orthogonal to that cylinder feature.

[[DW...]]

Please sign in to view this quote.

Huh, you learn something every day. I swear I have done 180° scan paths on cylinders and it does not go underneath as described by OP.

[[Ri...]]

Please sign in to view this quote.

It's not guaranteed to do that. I've had a part loop 10 times and never crash, and then the next run crash. It's random, so I just don't run the risk anymore.