Manual Alignment Reversing Vectors

[[Da...]]

Recently on our DuraMax, we've had programs get flipped during manual alignment, resulting in a crash.  These programs have run fine before, so it is a recent development.  I've done some preliminary troubleshooting like check probe qualifications, base and start alignments, and even rebooting.  Any thoughts on what could be causing this?

 

[[Ke...]]

I've experienced it with short cylinders in a Base Alignment, but using a simple Start Alignment (Circle + Point) usually corrects the issue 

[[Ma...]]

Don't use cylinders as secondary in base alignment directly.

Use two circles recalled into 3d line ( just recall their centers ) - This way you will have always stable direction.

In other alignments you can use cylinders freely - just not in base alignment.

I got problems while having a sphere as primary and cylinder as secondary ( forged towing hook ).
Even with manually scanning at right spots it was switching direction.
If you help yourself with start alignment with 2d line, then cylinder in base alignment is ok too.

[[No...]]

When using cylinders for alignment, always make sure to probe the points in the correct depth order. That means if the first circle path is defined on the +X end and the second on the -X end, make sure to probe the points in that same order during manual alignment. Otherwise the axis may get flipped and with it the whole alignment (you can't trust the CAD view here). You don't have to probe all the points shown in the alignment dialog, just make sure to follow the correct depth order. There's still a slight chance it may get flipped despite keeping the order (cylinders are a bit touchy here - it depends on the diameter/height ratio), so as Martin said, it's better to use two circles and a 3D line instead.

Edited 10 hours ago

[[Ra...]]

Norbert is correct. This also applies for 2D lines, the order of points taken matters. Used to happen to me all the time when I didn't know any better.