I am trying to create a solid with multiple countersink holes in it.

First I create a Rectangle in 2d then using the pushpull tool, I give it some depth in the z axis
next I switch to plane view, and create a countersink hole, all is good up to this point
next, using the linear duplicate tool, i select the countersink hole and setup the x/y dims,
I also set as associative
The duplicate creates multiple countersink holes but also duplicates the the solid that the countersink hole is in
I can not seem to deselect the rectangle solid when performing the linear duplicate. what step am I missing.

Edited by user Monday, September 4, 2017 8:06:34 AM(UTC)  | Reason: Not specified

Tim, Thank you for the help with the Linear Duplicate question, I watched the video which made it very clear, and finished my project.
I just purchased the software a few days ago, and still have a lot to learn, i have no previous 3D experience, so I appreciate the help very much.
Thank you again
Bob