Simplify3D User Forum

I imported 2 stl files
ran the Dual Extrusion Wizard, this resulted in a grouped model
I then selected the group and rotated it -90 on the Y axis.
Then I pressed CTRL-T (drop to table)

It did NOT drop the group to the table but dropped each individual stl file to the table, resulting in them being misaligned
note that one of the STL files does not actually touch the table when in that direction.

Its fun working with multi-part models!!

I'm guessing that you didn't "group" the parts together using the Group Selection on the Edit drop down menu. This is designed to prevent the individual bits moving around independently....and will allow the Centre & Arrange to work how you want it to. Just selecting multiple parts doesn't have the same effect.