Midplane through a rectangular pattern

[markGJ4RF]

I have a set of bodies created using the Rectangular Pattern tool, but the quantity of repeats is a defined parameter, not a fixed value.  If I create a midplane using the outer-most planes of end bodies in the pattern then I get a reasonable midplace, but as soon as I change the parameter driving the number of repeats (a) one of those planes goes away and the midplane is now using cached geometry and (b) the midplane is no longer in the middle of the pattern.

The attached file is a very simple example.

The only solution I can come up with is to use equations to calculate the extent of the pattern based on my other parameters, which seem a bit clunky. Does anybody have a better suggestion? Thank!

[jhackney1972]

Exercising your supplied model does not exhibit any issues with the set midplane unless you pattern count goes below 2.  Maybe you can create a video showing your problem and post it.

[g-andresen]

Hi,

A variable number of instances leads to a variable length of the pattern.
The centre plane is calculated as an offset from the starting point from this total length.

günther

[markGJ4RF]

John, thank you for your reply.  @g-andresen below got the intended sense of my question which is to keep the midplane in the middle of the pattern no matter how many repeats there are.

[markGJ4RF]

Thank you. Your solution works, but it is what I was hoping to avoid (my original post refers to "use equations to calculate the extent of the pattern based on my other parameters").

The reason I want to avoid this is ultimately laziness, I suppose. F360 is doing the calculation for me already when it performs the pattern operation, but then I need to do the calculation again to figure out the offset for the middle. Not a huge deal, just a little less convenient and perhaps slightly more prone to having the two calculations come out different (through rounding or something).

I'm still new to F360, so I appreciate having you folks around the help me find my way.

[g-andresen]

Hi,

Ultimately, it always depends on the initial situation.
Either you fit an pattern into a given housing, for example, or you create a housing from the conditions of an existing pattern.
Further settings are conceivable for both situations.

günther