Part 3 - Case Preparation
With three useless (to me) Macintosh IIcx cases from which to choose, I picked the least scratched and dented parts from each. The case I chose was yellowed, but I didn't care about that, since I was planning on painting the whole thing anyway. None of the parts was clean, so all had to be scrubbed with detergent. It's not just that I'm picky about handling dirty parts, it's easier to mark a clean part with a pen or awl than a dusty part.

As you can see from the photograph, the Yosemite motherboard is a tight fit width-wise in the Macintosh IIcx case and would require a lot of test-fitting during case modification.

	Tight fit overall.

	Tight fit left front (facing back).

	Tight fit right front (facing back).

Although it would seem the motherboard could fit into the case without further modification to the inside sides, this is not the case. The thickness of the case sides tapers from a small amount (I didn't actually measure it), to a formidable thickness at the bottom of the case. In addition, there were reinforcing ribs on either side and mounting tabs that would require removal for the motherboard to fit.

	Motherboard mounting tabs and case side reinforcing ribs to remove.

I simply scored the plastic where needed and snapped it off with a pair of pliers. Not very neat, but effective. I then routed out a groove for the motherboard on each side of the case using a Dremel motor tool and burr bit. I placed the groove about 3/8" above the bottom of the case since I would be using 3/8" tall stand-offs.

	Motherboard groove. This picture was taken after I had installed the stand-offs and trimmed the rear of the case. As you can see, only a slight depth of plastic needed to be routed out.

I repeatedly test-fitted the motherboard mock-up during this process until the mock-up rested on the bottom of the case without its edges pressing tightly against the case sides. I was a little worried at first that removing the reinforcing ribs and all this carving would weaken the case and make it too flexible, but apparently Apple engineered a very sturdy case and my worry was for naught.

Now that the motherboard mock-up fit perfectly, I placed it in its final position within the case. Then I used a 9/64" (≈3.6mm) center punch to mark the position of each stand-off in the bottom of the case. The case plastic is somewhat soft and easily marked. I didn't want too many screws showing on the outside of the case, so I decided to fix the stand-offs in place using an epoxy adhesive. Before mixing the epoxy, I trimmed and sanded each stand-off position so the adhesive would stick well. Then, I used cyanoacrylate adhesive to fix the stand-offs in place to verify their position with the motherboard mock-up. With everything looking good, I mixed up a batch of epoxy and dribbled it around each stand-off. This was left to cure for 48 hours.

	Stand-offs in place. Again, this picture was taken after I had trimmed the rear of the case.

	Stand-offs in place close-up.

When the epoxy had cured, I fitted the motherboard mock-up in place. Then, I marked where the PCI cards would butt up against the back panel. This is where I would trim off the rear of the case in preparation for mounting the acrylic back panel. I snapped the cover on the case and taped it to the case sides at the rear, since cutting away the back of the case would also cut away the tabs that held the cover in place. Finally, I set the fence on my trusty 10" (254mm) Delta table saw and, using a tungsten-carbide finishing blade, cut away the back panel in eight passes, two for each side. I had to be very careful to keep the case aligned with the fence for a square cut.

« PREVIOUS	« HOME »	NEXT »
•  Introduction  •  Planning  •  Patterns and Templates  •  Case Preparation  •  SuperDisk  •  CD-RW  •  Drive Activity Lights  •  Rear Panel  •  Switches  •  Test Fit  •  Cable Management  •  Painting  •  Final Assembly  •  Gallery  •