(Continued from Page 2)
Since I took part in Apple's power supply exchange program the tower was already relatively quiet. I thought it needed better cooling even with my new "Hi-Flo" HiPo G5-esque shell. The stock 120mm internal Pabst cooling fan was not centered on the HS and the upper half of the HS did not receive adequate cooling (Upper refers to the "upper half" when the case is closed. With the case open it refers to the right half of the HS). If I placed my hand on the HS with the tower running and it was very hot. I wanted a quick and dirty solution to duct the airflow over the HS and to better isolate it from the rest of the case. What would work better than a shroud?
A shroud was first constructed from cardboard and the dimensions transferred to sheet metal purchased at Home Depot. The shroud was designed with an offset, integral fan (10mm x 40mm Sunon) to better cool the copper heatsink. It was painted with high-heat white paint.
In addition an exhaust (20mm x 40mm) fan was attached to the other side of the HS for better airflow.
Both fans are wired for 7V so they are relatively quiet while providing additional cooling. In the future I'd like to remove the rear 40mm and add a 120mm exhaust fan to the case exterior and duct it over both the HS and hard drives.
The end product wasn't so pretty but it worked well. A more professional shroud is planned in the future with slightly different fan placement (it should be moved closer to the bottom of the HS to better augment the 120mm Pabst and avoid interference from the optical drive cable when the case is closed).
The power supply is a major contributor of heat in the Apple MDD tower design. I considered moving it outside the case but decided against it for aesthetic reasons.
I used some Home Depot sheet metal to make a duct to direct the air intake for the dual PS fans to cooler external air from the front and top of the case instead of sucking warm, internal case air in from underneath it. It is attached with 1/4 magnets. This essentially isolates the PS airflow from the balance of the case.
I had to trim the rear of the GF4 Ti video card so that it would clear the PS duct.
The large top vent allows errant convection currents to escape the case innards.
A Few Finishing Touches:
Open cell foam was cut and secured over the large top and front case openings to help keep the interior cleaner and cooler.
The first front aluminum power panel was finished with vinyl film but I was not satisfied with the overall quality. It was held in place with double sided sticky foam tape.
A new smaller power panel was also created from 0.8mm 5052 Al sheet. The finish is much more professional than the original. It is held in place with small magnets epoxied to the rear of the panel. I attached a small lexan dome to the power button with double sided cellophane tape so it was easier to access through the panel.
Initially, opening the case was accomplished by inserting a thin, rigid metal object, such as a hex key, through the perforated metal depressing the lever that operated the side panel locking mechanism. It wasn't elegant but it did allow for cleaner case lines.
Ultimately I removed the side panel locking attachments and used 3/8 by 1/8 magnets to hold the door shut. It holds the side closed quite securely and also provides for easy access.
The machine went back together fine and worked great (no leftover screws ;-)).
However when removing the perforated shell from the finished assembly I found that the vinyl scratched and/or tore somewhat easily on the metal edges. The design was intended to provide easy shell removal and the easily damaged vinyl would be an impediment. It was definitely time for those Aluminum side panels.
5052 Aluminum sheet (~4.7mm thick) was used to construct the new side panels (They were surprisingly heavy). There were quite a few deep scratches in each panel when I received them. About 40 minutes of wet sanding per panel provided a smooth, slightly directional, brushed finish which removes 99% of the scratches from shipping. The surface cosmetics are acceptable but I'll likely polish them at a later date. The panels were attached using black button head socket cap screws (M5, .8 pitch, 20mm long).
The Aluminum panels really finish the cosmetics nicely although the look doesn't really match the Apple Cinema display.
For legs I used four solid lexan cubes and attached them with double sided foam tape (That stuff is very strong).
The fit and finish is basically what I had originally intended.
It is not as nearly shiney as it looks in this picture. Me like. :-)
The M(ach)5 name comes from a combination of "MDD" and "G5". It is also an "homage" to Speed Racer. ;-)
In the future I may build two matching 5.25" FW drive cases for the optical drives. I've also thought about creating a new display enclosure for the Apple 20" LCD but for now it will remain in standard trim.
As much as I enjoyed performing this mod I'm happy that it's complete.
Thanks for the great site.-Louis
= Back to Page 1 or Page 2 =
For other System or Case conversion articles, see the Systems Topics page.