Projection vs Intersection

[[Ro...]]

What is the difference between an intersection and a projection of a cylinder onto a plane? A program I am working on is using a projection to a plane to get the true position of a bore at a compound angle. I have not seen that before, and personally would have used an intersection to said plane. I ask because I get very different results when using one vs the other. 

[[Ri...]]

I believe that the biggest difference with projection is the order in which it is set, so make sure you aren’t actually projecting the plane to the cylinder. 

[[Ro...]]

I believe the order of the projection is correct, but the results for position are quite different. If I choose the cylinder for the position then choose projected tolerance zone, and choose the plane for Feature 1, and set offset and reference length to 0, I get very similar results, less than 10 microns, compared to using the intersection of cylinder to plane, so I believe the intersection is the correct way to do it. I just was curious to why the cylinder projection is so much different. 

[[Ke...]]

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Perhaps the Intersection is translating along the Cylinder axis (until it intersects the Plane); whereas, the projection is just using the origin (or centerpoint) of the Cylinder and (looking for a different word besides "projecting" 😂)...projecting it directly to the Plane 

[[Ro...]]

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Yea, after more thought, that is the conclusion I have come up with as well. 

[[Ri...]]

Intersection would be projected along the axis of the cylinder normal to the axis of the cylinder until it hit the surface you told it to intersect. 
 

Projection would be taking the axis of the cylinder and projecting it along the axis of the cylinder normal to the axis of the surface you told it to project to. 
 

if the two surfaces aren’t very square to each other then you would see vast differences. 

[[Ka...]]

 
That’s a very clever question!
Is that really the case? 
Is the projection point the point where the axis of the cylinder intersects the projection plane?
Is the point of intersection the point where a line perpendicular to the projection plane intersects the MIDDLE of the cylinder’s axis?

 

What is completely unclear to me is the position of a cylinder in general. This is because the question arises as to which point on the axis of a cylinder is used to determine its position.