Alignment

[[Cl...]]

I have a small .075 driver (X shaped) at the working end. The 4 tabs aren't long
enough to get more than a .015" long line to use for my planar rotation in the
base alignment.

Initially I created a symmetry from the two opposing lines and used that for my rotation.
I want to try something different, so I created two theoretical points and constructed a
3d line using them and the symmetry for my rotation. I would like to know your opinion
on doing it this way.

The first pic, just to show what it looks like.

The second shows the 2 theoretical points (Y+/Y-) & the symmetry to make a 3d line for planar rotation.

The third pic is my initial symmetry creation from two short lines for (symmetry) planar rotation.

Part_Solid.PNGAlignment_2.PNGAlignment_1.PNGPart_Solid.PNGAlignment_2.PNGAlignment_1.PNGPart_Solid.PNGAlignment_2.PNG

[[Cl...]]

Part_Solid.PNGAlignment_2.PNGAlignment_1.PNG

[[To...]]

That will align your part to the machine's rotation and not the actual part.

[[Cl...]]

Because of the theoretical points?

Even though I'm using the symmetry created from the part?

[[Ja...]]

I see people using symmetries, constructions, theoretical features, etc. in base alignments from time to time. It makes me cringe and here’s why – All constructions, theoretical features, symmetries, etc. all need something to reference from like an origin, orientation, etc. If you use these types of features in a base alignment, where are they getting their needed information from? Nowhere! The base alignment hasn’t been established yet! So Calypso is going to use a best guess (literally and figuratively) and you’re relying on that guess to be correct. The majority of the time it will be, but sooner or later it’s bound to be wrong (IE – It thinks Y is Z or something similar). Then what’s going to happen? – probably a nasty crash. So never use those types of features in a base alignment unless you’re also using a start alignment. And never have those types of features in a start alignment, ever! Don't give Calypso the opportunity to guess. Always lock down your 6 six degrees of freedom 1st (even if you have to probe the fixture or something else to lock down the last degree) before using any of those features. I had to learn that the hard way early on in my programming career.

[[To...]]

Please sign in to view this quote.

Actually, the machine's coordinate system, so in this case the rotation around Z is relative the machine's XY axis. Or, a previous alignment if you made a change after using his original line symmetry.

[[Cl...]]

Below the trihedron is the main datum (a cylinder) which I used for my spatial rotation and XY origin.
A point on the very top for Z zero, and the 3d line created from the two theoretical points & a symmetry
from two scanned lines for planar rotation.

I did use a start alignment with actual probed points. In retrospect I guess I could have used a similar
strategy for my base alignment. I used the theoretical points because I saw Zeiss do it in a program
they wrote for us.

I figured it must be right if they did it, but I wasn't sure.I simply wanted a longer feature to use for planar
rotation, and thought that might be a good way to get it?

[[To...]]

Please sign in to view this quote.

The plot thickens....3d line created from two theo. points & a symmetry from 2 scanned lines.???? I can't understand why you use 2 theo points for the BA. can you post a screenshot of your BA window?

I might create a symmetry construction from 2 points, one on each side the +Y leg and another symmetry construction from 2 points on each side of the -Y leg and then create a 3d line recalling the 2 symmetry constructions.

[[Cl...]]

I thought about doing that, but I wanted a feature for planar
rotation that was at least as long as the top cylinders diameter.
Probed points wouldn't give me that.

I appreciate all the input. I'll stay away from theoreticals for
alignments in the future. 😃

Have a great weekend.

[[Ja...]]

Tom, I’ve seen Calypso guess wrong more than once when some type of construction gets used in the base alignment. So I’m wondering how that can be if Calypso ties everything to machine coordinates? Not trying to start something here, just not understanding.

[[To...]]

I've heard of some horror stories, so there may be more to this, like you say.

[[To...]]

Please sign in to view this quote.

Making theoretical features is not going to help you either, since they are based from your alignment.