Well, as the due date for project Ophidian nears I have been kicking it into high gear to complete my mods. I pulled an all nighter last night but it was worth it as I was able to complete nearly all of my work leaving only my wiring for today.
Here are some pics of the project in progress:
As I mentioned in previous posts, I am painting all the screw heads and the wheel frames while I am at it. I think the small details make all the difference.
I am fitting the bottom of the case with a 1/4" thick sheet of acrylic. I am using cast acrylic for its clarity. This feature has 2 functions, I plan on using it for a lighting experiment and also as a window feature on the bottom of the case. Anyone who has ever followed any of my work logs knows, I like floor boards on the inside of my cases. I just think they look sharp. However, for this case I decided to do something a bit different, I am cutting out the bottom of the case and creating a large window that will allow light from the fans to spill out the bottom of the case.
I have to start buy cutting the acrylic. This is the only sheet I have so I cannot afford to screw it up. If you plan on cutting acrylic I suggest using a jig saw. Get a blade with the finest teeth you can find. I like to use my bi-metal blades as they have very fine teeth. I run my saw at maximum speed and move nice and slow. Cast acrylic is particularly brittle so you need to take your time.
I use 2 Irwin clamps and a nice straight board to create a fence for my saw however I have found that my work comes out much better if I do it free-hand. Just 2 cuts and I have a piece of plastic that is a precise fit to the bottom of the case.
Before I can cut the window I need to mount my wheel frames. I need to be absolutely sure that I have all the screw holes for my wheels accounted for prior to cutting the window. When planning a project I have found that making a step by step list is the best way to avoid costly screw ups. I usually prepare a list of each step in the mod and the order in which they should be carried out.
I need to drill 4 holes per wheel and I will be using the same bolts and nuts to mount the wheels that I used on the fan grills. After drilling the holes for the wheel frames I am better able to plan my floor window cuts.
I am creating a nice big oval window between the back set of wheels and the hard drive cage. I start by punching 2 big holes with a 4.5" hole saw then I connect the 2 holes with my Dremel. I cleaned up the edges of the cut with my Dremel and a file.
The next step is to prepare the acrylic sheet for mounting. As part of my light feature I am putting LEDs in the acrylic with the hope of transmitting light to the edges of the plastic to create a rim of green light around the bottom edge of the case. I am placing 4 green LEDs in the acrylic and concealing them below the hard drive cage. With all of my lights concentrated at the front of the system I am going to need to polish the crap out of this plastic to ensure the best light transfer possible.
I started by drilling the holes for my LEDs. I am using a 3/16" plastics drill bit. This will give me the right size hole for a 5mm LED. I will need to expand the hole slightly to allow the back edge of the LED to penetrate the plastic, for this I am using a universal bit. I placed the holes in a staggered pattern. Since these LEDs are going to be hidden under the hard drive cage I did not worry too much about precision and just eye balled it. Once my holes were drilled I used the acrylic as a template and drilled corresponding holes in the bottom of the case.
Polishing plastic takes some time but if you have the patients there is a big payoff. I like to shape things by hand whenever possible and on this case I wanted the acrylic plate to have nice beveled edges. I clamped my belt sander in my bench vice and began to work the plastic one edge at a time. Using 120 grit sandpaper, I was able to quickly get the shape I wanted. With practice, you will be able to get nice even beveled edges on all sides.
Once the bevels were created I moved on to wet sanding. Using 400 grit sand paper and water I sanded all the rough spots out of each of the edges. It took about 40 minutes of alternately sanding and dipping in water to get the nice smooth edges I was looking for.
After wet sanding I moved on to polishing compound. Many people like to sand with finer and finer grits but I have found that my Casewell polishing kit allows me to skip these steps. Using a medium grade compound and wheel I am able to achieve a glassy finish. I followed that with a polishing rouge that's the consistency of lotion. Following this final step the acrylic is smooth and clear as glass. Polishing in this way is a messy business but you will get a super high shine.
After completing the acrylic plate I trimmed my window with rubber "U" channel and then mounted the acrylic plate by sandwiching it between the chassis and the wheel frames. A few nuts and washers and the mounting is complete. Mounting this acrylic was not without its problems, I had to mod the plastic mounting brackets on the front of the case in order to make everything fit properly.
Finally I have everything together! In retrospect, I think I would have gone with black wheels if I had it to do all over again. The last step for the night was to slip a PSU into the case for testing and remount the fan grills with our newly painted screws.
Okay it's 4:15am...time for bed.
Next post: wiring and testing