problem usung array and solid difference

I wanted to make an object with a repeating relief pattern. what I did was model up a shape to take away from the material. I did an array of 12 in the x direction. I made a box and then tried the solid-difference from the pulldown. I received an error, so I did it again but selected them 1 at a time. It worked for the first 3 and the last 7, but still gave me an error on the 4th and 5th. I was able to work around this by copying on of the other positions to these positions and it worked. I was wondering why this happened and if I was doing something abnormal, even though it worked on some of them? I am using rhino 4 commercial.

Thank you
Mike

Boolean operations can give weird results in any programs, not just Rhino. I've seen similar errors in many different CAD and modeling programs over the years. Sometimes moving objects a very small amount can help.

Hello,
depending on your model size you can increase your tollerances in options, it might work.
otherwise you can try installing the evaluation of RhinoGold and use its boolean features, you have better odds with it.