The first thing I needed to do was free the components from the old case. I wanted to use the system tray from the old case, simply because it contains a back plate for the ports and PCI cards. Removing this wasn’t trivial, but not really that hard either.

The system tray is hinged on one side and that hinge is riveted in place. I simply drilled out the rivets and popped off the hinge. I removed the plastic bits of the old G4 case, and since the airport antenna pokes out the bottom of the system tray I removed it so the tray would sit flat. I have no intention of getting an airport card for this Mac, so it’s pretty much useless.

The only other bits I salvaged off the old case were the power on, restart and programers switch buttons. Just pry gently and they come right off the faceplate. The plan was to reuse them in the new case.

Once I had everything out I put it together on a piece of plywood I had bought. I hooked everything together just to see if my patient had survived surgury so far. It fired up without a complaint!

Now things get a little more interesting. Being a condo dweller, I really don’t have a nice garage or work area, just the patio. I needed some tools to work the wood, and my wife was kind enough to let me invest in a RotoZip saw. For anyone who works with tools, you’ve probably heard the saying “the right tool for the right job.” I will admit the RotoZip isn’t the best tool for everything I’d be asking it to do, but it is adequate and my tool budget couldn’t afford a whole workshop of equipment. It’s small, and capable enough to get me through this project.

The first thing I did was cut down the plywood base to size. The pannel came 2’ x 2’ which is larger than I wanted. I narrowed it down, and cut a hole in the bottom for the power supply fan. this means the PSU will draw air from outside the case, instead of pulling hot air from inside the case. That was intentional.

Now a quick note on the RotoZip. They make a nice little attachment for cutting holes in things. It works really great until you get more than halfway through your cut, then the center of the circle moves and you find yourself cutting a spiral. Neat huh? Well not if you really wanted a circle.

I’m sure the RotoZip folks mean well but I found it easier to cut two, almost half circles using the same center point. Then just free hand the little tabs left holding the center stock away. Learn from my mistakes young Jedi.

The next mistake I’ll get over right now too. I really should have waited to cut the hole in the base till after I had the sides assembled. Remember the old adage, “Measure twice, cut once.” Well dispite the fact that I measured everything four or five times, I still wound up making mistakes. The hole wasn’t a big problem, just the side of the case pushed the PSU over farther than I had anticipated, so I had to cut the hole a little larger. Not a big deal, and it’s the bottom of the case no one is going to see anyway.

I looked high and low for something to serve as feet for the case. I wanted something that would dampen vibration. I wasn’t able to find purpose built feet, but did have an interesting idea. The DIY store had some rubber stoppers. I bought four of them and drilled holes in the corners of the bottom piece. The stoppers fit in about half way, which leaves a nice gap for air to get to the PSU and they’re flexible enough to dampen vibrations.

I picked up three pieces of Redwood from the DIY store and really didn’t want to screw them up. I did measure the sides several time, and wound up cutting them a little longer than necessary and shaving them off bit by bit to get them to fit right. The front, left and right sides have they bottom edges cut such that they sit on the plywood base, but still overlap it. I believe professionals call this a rabbit joint. I also cut the right and left sides of the front piece so that it covers the right and left sides of the case. I drilled holes for screws rather than just glue it all together. I may still glue it for final assembly but part of me wants to just use the screws in case I wind up modifying the case later on.

I used the plunge router attachment for the RotoZip to cut out space for the CD Rom tray to slide in and out of the front. I also used this to remove stock where the power button would go. This button only stick out about 3mm so I needed to remove a good bit of stock, without cutting all the way through the front cover. I then drilled holes for the buttons to poke through.

The left side of the case is the most interesting. The setup of the case has the PSU and disk drives on the left side and then the logic board. I wanted to draw air in the left side, past the drives, over the logic board and out the right back corner of the case.

I cut out about 1cm depth on the inside of the left case piece, then adjusted the RotoZip 5mm deeper and cut again, but making a smaller box. Finally I adjusted the RotoZip to go all the way through, and cut 4 slits for the incomming air vent. Then on the inside I covered each of the vents with strips of wood, secured to the case in the little step left when I routed the two different sized boxes. The point here is to allow air in, but still baffel the noise from getting out.

I assembled the three sides of the case and then put the PSU, logic board and case fans in where I wanted them to go. I placed the back (which was just plywood cut to size) and then traced the outline of the components onto the back.

Then I used the RotoZip to rough out the openings, and the router attachment to clean up the edges. For the most part I just cut it free hand, and it came out pretty well for the back of the system tray. I did use the RotoZip circle guide to cut the holes for the case fans, and then the router attachment to remove stock so the fans actually sit inside the back of the case. I also removed some stock around the PSU, so that when inserted, the PSU attaches to the back with screws.

Next up was the hard drive mounting system. I cut two boards and put quarter inch channels in them at regular intervals. Then I cut away most of the center of each to allow for air flow. I used some aluminum channel I bought at the hardware store, cut to the length of the hard drives, drilled holes and attached them to each side of the drives. The drives then slot in nicely between the brackets. This leaves the drives in vertically and once the top of the case is made, they won’t come out as the case will be very close to the top of the brackets.

The CD holder was similarly configured. I cut two “L” shapped brackets which are attached to the bottom plywood, and shaped such that they clear the logic board. I then put two pieces of aluminum angle stock and drilled holes to fit the cdrom mounting points.

With the brackets in place on the bottom, I attached the PCB containing the power button to the front of the case, assembled the sides and put all the guts into the case. I don’t have any pictures of the final cabeling, as it’s not secured or neat just yet, but it will be routed and secured for final assembly later on.

I’m happy to say the whole thing still runs. I’m happier to say it actually runs quite a bit cooler. Using two 80mm case fans to draw air through the case, my cpu thermometer reads 20 degrees cooler than in the old Sawtooth case, and this is with just a temporary cover over the top.

Unfortunately the CPU fan really does stick out aubibly now, so I will have to deal with that eventually but things are moving along in the right direction.

Next step: fashion the top cover, and finish the case with sanding and some sort of protective finish.

The Quest to Silence a Mac
Mon June 19 2006

Building The Basic Box
Sat September 02 2006