Step 3.  Install the Standoffs

The standoffs are mounted to the back panel of the enclosure and attach to the component side of the PCB with the seven segment displays and tact switches facing out.  The six plastic posts in the back panel must be tapped 6-32 to hold the standoffs.  You should use a small hand tap with a gentle touch.  Be careful to stop as soon as the front of the tap hits the bottom of the post hole otherwise you will strip the threads.  If you do, don't worry since you can just epoxy the standoffs in place just as well.

The hex standoffs are made of aluminum and have a 6-32 male thread on one end and a 6-32 female thread on the other end.  The male thread is slightly too long for the plastic posts so you must grind or cut about 1/16" from the end.

Install the six hex standoffs in the tapped posts.  I would recommend tightening them firmly by hand.  If you use a tool, be careful not to strip the threads.