Repeating pattern feature measurement confusion

[Anonymous]

I am confused about measurement for a repeating pattern. I have a square 90mm long. In the square I have a circle 10mm long. It is offset inside the square by another 10mm. When I go into model mode I create a hole based on the circle and use the repeating pattern feature to attempt to make a pattern with 9 circles spaced out between each other by 20mm. The glyph for Distance Type in Repeating Pattern options shows Extent should equal to the length of all the circles plus the distance between the circles. I know I want the distance between the circles to be 20mm. Since I am creating 3 circles for one side, it should be 10mm x 3 + 20mm x 2 = 70mm. That is too long and the correct value for Extent distance is 60mm. Is the glyph for Extend not correct? What am I misunderstanding?

In other words, if I set the length to 70mm, based on the glyph picture, that should equal 3 holes @ 30mm + 40, which when divided by 2, leaves a 20mm separation between holes which is what I want. But 60 is the correct distance. It seems maybe the glyph is not correct as it should show an additional spacer to match the quantity.

[TrippyLighting · Accepted solution]

Maybe I am  not exactly understanding what you are saying, but Extend only shows the distance between the center of the first and last pattern instance.

Extend does NOT include the diameter or otherwise dimension of the patterned object.

[Anonymous]

That would explain it but the glyph does not show what you describe. The Repeating Pattern Edit Feature properties shows:

Distance Type: Extend

The glyph picture next to that clearly shows an arrow going from one end of the object to the other end of the repeating object. That being said it makes sense now.

Total length to space out repeating pattern: 70mm

1 circle size: 10mm

3 circle sizes: 30mm

Distance between circles: 20mm

Distance to use for Repeating Pattern Distance parameter: 60

5 (radius of 1st circle) + 10 (diameter of second circle) + 5 (radius of final circle) + 20*2 = 60

It's confusing and would be simpler if it used the entire length of the dimensioned objects rather than just the center. I guess there must be some reason this was done otherwise it would not be done that way.