Approach vectors

[[St...]]

I'm trying to understand approach vectors. I've got cylinder 3 on the XY plane at +30 degrees from X axis. The RDS head is at A -30, B -90. It's approaching the cylinder at a weird angle and crashing the chamfer area. I want it to approach directly in line with cylinder axis.

[[Ri...]]

Since it is not square to any of the sides of the cube, this is where you will need to have a significant amount of clearance distance for it to travel along the axis of the holes. 

[[Ma...]]

What value is in "Cleareance data" for approach? I use 0 for cylinders and curves - with non-zeroe value it's making bad movements.

[[Pe...]]

It's approaching from your clearance plane.  You have two solutions that would work for it:

Since it is an angled hole you can use clearance distance.  You probably want to turn on the graphics to see what it will do here:

 

Then you can set a clearance distance that it will go to before entering the feature:

 

Your other alternative would be position points:

Just make sure you have one before and after your circle paths.

[[Sv...]]

In such situations, I always use the intermediate position, as described by Perry Steever2.

[[Ri...]]

If you create an alignment to the feature at entry, you won't need position points.

All you have to do is increase the Clearance Distance.

If I wanted to approach the hole location you have, my alignment would be at the intersection of the center of the hole and the OD body.

For an example, in the attached image, see Alignment Ref #2.

Then I set the Clearance distance proportional to the Clearance Cube from Clearance Plane settings.

Now you can navigate without collisions or CMM Position Points.

With a proper alignment all of your vectors will be correct.

Edited 1 hour ago