Saturday, November 24, 2007

Hinges Revisited

The whole episode with the hinges has gotten me a bit distressed, so this evening, I spent a lot of time working on my mangalore rifle buildup, which also has its own blog here. I made a lot of progress on it tonight, so if you haven't had a chance to check that page out, now would be a good time.

But let's talk about the tricorder!

Tonight my goal was to take another look at those blasted hinges, and see what I could do.

I started by removing the two outer hinges. These are the ones that have the wires soldered to them. This was actually pretty difficult, as the putty I am using is like solid rock. So I had to dremel away enough of the putty to expose the screws, then clean out the grooves in the screw head with an x-acto, THEN unscrew them using a tiny phillips head screw.

After that, I just had to scrape out the epoxy and excess putty. I was back at square one.

I figured out that the problem was that the hinges have a coating on them that makes them non-conductive. I needed to figure out where to go from there.

I dug up a few more hinges that I had lying around. Laying around? I dunno. But anyhow, I found some more hinges.

I lay (laid?) them flat on a piece of sand paper, and sanded away for a while, until it looked as if the surface had changed a bit. Got less clear. More foggy. Looked like I was down to bare metal. I rigged up my power supply, connected everything, and voila! (not to be confused with "viola", which is an instrument. Or "walla", which is a noise drama kids make when they're onstage simulating background/ambient crowd noise)

This was promising, and it looked like I was on the right track. It now appeared that as long as I sanded the coating off the back side of the hinges, they were able to conduct electricity. That was cool.

The downside is that not all hinges are created equal. The danger with almost any tricorder build up is that the hinges are not always making contact between their two halves. As you open and close the door on the tricorder, the hinges sometimes lose contact, and therefore lose conductivity. So the power cuts off, and the lights go off. The main bummer is that it usually causes a flicker in the lights. It would be different if they just shut down. But it's an annoying flicker instead.

I went through the three or four extra hinges I had on hand, and discovered that each of them behaved differently. Only one of the hinges maintained power flow through the entire range of motion. All of the others cut out somewhere along the arc. No big deal, as I'll just have to pick up some more hinges later, until I find one that works properly. I tried using pliers to squeeze a hinge tighter, but that didn't work.

I took my old hinges, melted off the wiring. I tried sanding them down and testing them too, but they suffered from the connectivity problems described above. Off to Watto's Junkyard, I suppose.

Since I had one working hinge on my hands, I soldered it up, and installed it following the same proceedure I outlined previously in this blog.

JUST to make sure I didn't make the same mistake twice, I rigged up power and tested it to make sure all was right in the world. And it was. And it was good.

Tomorrow, I'll need to find some more hinges, and continue with this madness. I was really hoping to have this tricorder ready for painting by the end of the weekend, but this hinge business was a two day setback. Not sure if I'll make that deadline, but I'll keep working.

No comments: