Wednesday, September 12, 2007

The perfect geek material

I never like wood, but I thought it was the only material that you can custom in your garage. Over the years I have a circular saw to cut 2"x4" beams for play things, now the saw is being recalled. I also have a little power sander to smooth the coarse wood so as for the surface not to be too tough for the touch. I once brought a jigsaw to build a custom corner table. I thought it was good but it got thrown away. An fake antique table replaced it.

I was looking for something to replace the cardbox in the yard, when I come across acrylic. I thought it was perfect. It's look like glass, lighter but tougher. And you can cut it to size with a knife. Perfect, just what I needed. So I designed a rather complicated box with lots of compartments, doors and openings in it, using a free CAD package.

I fit my design into a 2'x4' flat piece of acrylic at 1/8" thick. When the piece comes, it was perfect. It really looks good, crystal clear. It was protected by plastic film so you cannot scratch it while cutting it. The thickness is just right. It's just tough for you to build a strong box. Any thicker cost a lot more, and any thinner it feels plastic instead of glass. But there's one catch. There's no way you can cut it with a knife, at least not a decent long edge.

So I brought out my jigsaw. It's tough work. It's very slow to cut through the acrylic compared to wood that is a lot thicker, which is expected. Also, you cannot make a straight cut with a jigsaw, unless you have a decent work bench, which I don't. I should have ordered custom cutting which is more expensive than the material itself. At least for the long cuts, I should use some help. But I soldiered on.

The good thing is that, at a right saw speed, the blade create just enough heat to melt through the acrylic, but not too much melting, giving a nice smooth edge. The saw dust are basically acrylic melted into tiny beads. It's everywhere but a lot more pleasant than wood dust and it's much easy to clean.

The bad - the unexpected jigsaw instead of a knife leaves me with rectangles big and small, all without straight edges and right angles! I know it would be a challenge to fit the pieces together. Also, the dimensions are more than 1/8" off after cutting. So I have to run through the CAD package to made alterations as I went along.

Luckily I brought some small right angled wedges to help to glue the pieces together at the corner, and some squared tubes to help with the squareness of my box. And I settled for some toxic solvents for a quick welding of the pieces, instead of using slow solvents and requiring clamps that I don't have, and don't know how to apply in small spaces.

You can imagine the final box is comparable to a cardboard box using coarse tapes to stick the pieces together. But acrylic is something. You can see the glue, it's clear but there are bubbles in it. It's hard not to use excessive glue for the uneven pieces. It drys hard and visible, but it's as clear as the acrylic. Basically it's just acrylic melted and reformed. The wedges at the corners are ugly, no sides are straight and barely square. No edges are smooth.

But the whole junk is rather addictive to look at. It's my junk and it's like glass suspending in glass. You got to enjoy the fine details, like uneven application of the glues on the edges and hinges. The curved edges, and the blurred edges just like glass. Best of all, it's tough and highly functional. If I order custom cutting for the large pieces, or invest in a bench saw, it would be perfect the 2nd time round.

I can imagine 1/16" thick sheets will be perfect for delicate things, such as custom electronic enclosures. You should be able to cut it accurately using knifes. Polish the edges and use thin glues that make perfect invisible joints. You can drill small accurate holes, or cut out large portions for a screen mount etc. You can order custom laser cutting for you name to stick on it too.

The major problem I had was needing a lot of motors with gearboxes to mount on my beautiful junk. It's just too expensive compared to the whole box, and looked ugly. You can get bare motors a lot cheaper, compact and powerful. But without gears and crank arms they are useless. So after exhausting the web to find something suitable, I cut a little piece of acrylic as the crank arm and drill a hole in it. I put the bare motor shaft in it and glue them together using gorilla glue. It surprised me that now it's a very tough crank arm! The rest of the problem is mounting the motor onto the box. It just need another small piece and screws to clamp the motor securely in place. Now even the motor mount and the crank arm are transparent and look good, with screw suspending in mid air.

I fell in love.


cowboyclaws said...

Pictures!!! I need pictures!!!

The Player said...

I deliberately use few glue so the structure is temporarily and can be modified more easily. Before I refined the electronics and wrings, making it into a full 7 day feeder, my dog passed away unexpectedly, though he was old, but still chasing the kids. Pieces began to fell off and I borrowed a few pieces to fix other things. Now it's in a corner of the garage, with nothing much to look at.