A good friend of mine does alot of video projections in dusty locations with his new Mac Pro tower. He asked me if i could build him something to keep the dust out so i set to work. I have a wood shop and a laser cutter that i have been using/learning for the last year and a half but this project was my first introduction to the 3D world. Autodesk was nice enough to give out their 123D software and thats where it all began. This was a first trial that has been a success, the case keeps the dust out and its easy to replace the filter. Made from 1/8 inch birch plywood, a $15 ac computer fan and a $6 auto filter. Completing this project opened up a whole new world for me with my laser. As the laser only has 2 axis, it can be a challenge to create projects that are not flat. I now have the skills and confidence to create 3 dimensional objects.
Step 1: 3D Modeling
After downloading 123D I set to work creating the 3D model. First I 3D modeled the Mac Pro tower, a cheap replaceable and easy to find air filter i found at the auto store that was just a tiny bit bigger than the computer, and an auxiliary fan. Then i made a shape i liked that wasnt too much bigger than my first objects and deleted out the original shapes to create a cover that would fit all my parts perfectly. I then sliced the object twords the bottom above the fan so that it would come out in 2 pieces. As the mac pro draws air from the bottom ring, I wanted the computer to sit inside the filter and be sealed just above the intake ring on the computer shell. This part of the project was by far the most time consuming as i had never created to scale 3D objects but it was also the most valuable and important part. I knew that if I took my time and got everything right, it would make the build so much easier. As this was the first try, i was hoping everything would fit right so i wouldn't have to do it over again.
Step 2: Template for the Laser
After the 3D modeling was completed in 123D Design I then sent my model to 123D Make to decide on the perimeters for the case. This is where you tell the computer what your material size is and how you want your shape to look. I decided on radial slices to keep the weight down and i also really enjoyed the look. The open style would come to my advantage as i needed air flow into the top and bottom, i just needed to figure out how to keep air from the middle. In 123D Make, i was able to inspect all the connections and add or subtract radials to strengthen weak areas, which led me to find that for my particular project, 21 radials and 21 verticals look the best. This program is an amazing time saver as it calculates all the groves and notches, i can only imagine trying to draw that all up on my own to scale. My biggest complaint with the program is the nesting capabilities, which are not that efficient. I ended up sending the templates into Aspire to re-nest all of the parts and was able to cut my material use in half by flipping and nesting pieces inside each other. Once that was complete I sent the templates to the laser cutter, where i cutout the corresponding shapes from 1/8 inch birch plywood that i had stained black.
Step 3: Cutting and Clear Coat
My laser bed is 3'x4' so it only took a few pieces to get the job done but it could have been cut out on a smaller laser or cnc. 123D make will help you set all your perimeters for your machine. I chose to use black stained 1/8" birch plywood as it is cheap and i love the look. A huge advantage to the black stained birch is that it hides the laser burn marks and residue so you dont need to sand after cutting. Once the cutting was complete, i put a clear coat of polyurethane on each side to protect the pieces. Another advantage to this is that it adds thickness to the ply to make the notches even tighter, but it is something to note as sanding or painting the plywood will change your fit and for complex designs, this can be a hassle.
Step 4: Assembly
The next part was definitely my favorite, piecing it all together and hoping it fit! I cut out 2 rings of the same diameter and imbedded neodymium magnets in each one that would hold together the 2 parts. To conceal the magnets, i cut out birch laminate that i also stained black and adhered it over the magnets to hide them. The filter i chose was just a simple auto filter that happened to be just the right size. I really wanted my friend to be able to find a replacement filter no matter where he was that was cheap so this made the most sense to me. I then set to work figuring out how to keep the dust from the main compartment and keep the case from scratching the computer. I had some stainless steel coated mylar laying around from another project and decided the thin reflective material would work great and add a cool element to the project. I decided that adding felt to the inside would be another nice touch and keep the computer safe from scratches. I laser cut the felt and mylar to size and stuck the 2 together. The felt was the exact size and the mylar had some overlap. i found that with such a perfect fit, it required no adhesive to stay right where i wanted in the case and remained easy to remove if needed. I had left myself just enough room in the 3D design for the felt and mylar and really i just got luck on this one as i hadn't fully decided on the liner until everything was all cut out. I then installed the fan in the top with a few screws and routed the cord. i made sure to choose a common size and one that was powered by AC so it could be plugged into the wall rather than most computer fans which run of the DC power supply. I think this case would work without an auxiliary fan but i didn't want to take any chances with my friends investment. After everything was assembled I then added a few artistic touches and crossed my fingers for the moment of truth. She fit like a glove!
Step 5: Final Product
And then it was so.... surprisingly stylish and yet extremely functional. I am super proud of the way it turned out and my friend was super surprised. He had expected just some box with a filter in the side and a fan on top, what he got was something of an entirely different level. After completing the project, i just couldn't stop designing and thinking about new projects. Definitely like to thank Autodesk for giving the world their 123D products for free, they have really given anyone with computer access, the ability to make dreams a reality.