Perp Construction Two Cylinders

[[To...]]

I've always understood the application of a Perpendicular Construction was from the Mid-Point of Feature1, perpendicular to Feature2. However, when I do it with two parallel cylinders, the line is not at the mid-point of Feature1. It's at the origin of Feature1.
I also tried it on 2019 and it does the same thing. I'm loosing my mind....LOL

Anyway, the perp construction is showing me some really wacky results in simulation.

PerpConst_two cylinders.jpg

[[Cl...]]

I wonder if the depth of the cylinders makes a difference? I've had problems with shorter cylinders.

[[Da...]]

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What if you recall feature points from cylinder to a circle and use that as a top feature in perp?
I'm not 100% sure, but it might do the trick.

[[Ky...]]

Hello all,

Something seems very off with those cylinders, at least the actuals. Reading from the CALYPSO F1 help, when choosing a cylinder, it calculates the "center of gravity", which I assume is the overall average of points with each one weighted the same, but for some reason it looks like the software is calculating it more than 3000 (I assume mm) below the nominal.... It's hard to tell with the information I have with just that image.

Nominally speaking, at least, it seems to assume the origin of the cylinder is the center of mass, which is perhaps a bit strange, but CALYPSO does assume cylinders are infinite in at least most calculations, so it might just be the best with it can work with.

Hope this proves useful.

[[Ri...]]

I don't understand how you would generate a Perpendicular Distance between two parallel axis lines. There is no direction that either of the axis can generate other than Z, any other solution would just be pure assumptions by the software.

[[Ph...]]

Recall the "Feature1" cylinder into a point and use that. Do not use "Recall Feature Points" unless you're wanting to use the average of all measured points.

[[To...]]

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Had already created 3 circles from the 3 path strategy, so I could use the middle circle. Though recalling all of the cylinder points would give me the combine average info.

[[To...]]

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Sounds like you're not familiar with the "From the mid-point of Feature1, perpendicular to Feature2" guidelines.

Same thing would apply to 2 planes, right? However, with 2 planes, the 3d line will come from the mid-point of plane1, perpendicular to plane2. In fact, with 2 planes, the perp distance is the same as a Cartesian Distance. The only difference is you get a token 3d line with a perp construction.

Cart Dist_Perp Const_Comparison.pdf

[[To...]]

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I was also perplexed with the odd Z and the 15° angle.

[[Ri...]]

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I'm aware of how in principle it works, but I've never had it work properly between two cylinders. This same behavior is seen with the Cartesian Distance between two axis lines - which is why for a Cartesian Distance you have have to go in and specify the directions via the Primary/Secondary Datums.

It appears that the issue is around what it is calling the center of gravity for feature one on the axis line - which is why it behaves correctly when you use a point to recall the center of the axis line.

You can see this in your example where it is placing even the nominal perpendicular line at the origin of the two features, not at the midpoint. I don't know if this is a bug or not. It behaves correctly if you use a Plane as Feature 2 - it pulls the midpoint of the cylinder instead of the feature origin.