The Modern Firepower Pinball Project - Stern Backbox Hinges

The parts for the Stern Backbox Hinges came in from Marco Specialties.  I took plenty of pictures, so I'll let the pics do most of the talking this time.  Note, I did not have the washer in the photos, nor did I install the washer.  Everything seems to work without the washer, and as rarely as I will every pivot the backbox, I probably will never use a washer.  If I change my mind, I can always install it later.

The Stern Backbox Hinge Bolt assembly includes a Hex Spacer Nut, a Carriage Bolt, a plastic spacer, and a washer (no pic).

Click through for all the details...

The Williams Hinge Pivot Nut (Left) is very similar to the Stern part, but the threads are completely different sizes.

Another view, you can see that the Williams Hinge Pivot Nut uses an Allen key.

The Stern Hinge Pivot Carriage Bolt shown installed in the Stern Hinge.

On the reverse side of the Hinge, you can see the Stern Hex Spacer Nut and the Plastic Spacer.

To install, a 1/2" hole was drilled through the cabinet.  Note, only drill a pilot hole until the relief hole is cut (below).

Inside the Cabinet, a relief hole was drilled with a 1" spade bit.  The hole was sunk to approximate 3/8".

Shown installed, the Stern Hex Spacer Nut inside the cabinet.  It rests flush with the cabinet surface.

Shown installed, the Stern Hex Spacer Nut outside the cabinet.  The nut protrudes a fraction of an inch.

The Plastic Spacer is then installed on the Hex Spacer Nut.

Then the Hinge and Carriage Bolt are installed and everything is tightened.

Helpful tip:  I used two spacers, on installed and the other simply wedged between the cabinet and the hinge near the backbox, to ensure that the hinge was installed parallel to the cabinet.  Only then did I mark and drill the holes into the backbox.

 

Another angle, you can see the hinge remains parallel to the cabinet.  Plenty of room for the side rails to be installed.

Another view of the hinge bolted to the backbox.  I spaced the hinge 3/4" from the back of the cabinet/backbox.  Not sure if that is an official measurement, but this spacing appeared common in the few rare pictures I found that showed this angle.

The Stern Backbox Hinges fully installed and pivoting.  On a Williams cabinet design, no less.

I also installed a backbox latch to secure the backbox in the upright position.  You can see it unlatched in the previous photo.