Author Topic: LED / wiring question  (Read 2458 times)

tehmarken

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LED / wiring question
« on: December 31, 2006, 03:05:37 PM »
So I found a good Zaku, after being in the search for one about 2 months now (who woulda thought it'd be so hard to find a Zaku??). And I've got it in my head to put an LED in for the mono-eye. The head looks big enough with some minor cutting, but what I think will be the hard part is the wiring I'm planning.

I'd like to cut out one of the shoulder spikes and turn it into a rotational switch. I figure I can cut on off with an angled / conical cut, and glue on a piece of metal to sort of clip it in place and allow it to freely rotate. Then have the LED's wiring running from the head, into the torso, and out the shoulder to the shoulder pad and glue it on either side of the spike.

It looks like I had plenty of space to put a small battery either in the torso, or possible even on the shoulder.
The only thing I'm wondering, is the best way to secure the wiring. Would regular crazy glue be enough to hold the wire in place and not melt, or would the current cause enough heat along the wire to melt the glue? Would putty be a better idea for securing the wire?

Major Blah

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LED / wiring question
« Reply #1 on: December 31, 2006, 03:25:36 PM »
I don't think you have to worry about too much current melting the plastic, it's not going to happen.  Just make sure you add a series resistor to reduce the current going to the LED to get a more consistent glow that lasts longer.

tehmarken

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LED / wiring question
« Reply #2 on: December 31, 2006, 03:33:45 PM »
Quote from: "Major Blah"
I don't think you have to worry about too much current melting the plastic, it's not going to happen.  Just make sure you add a series resistor to reduce the current going to the LED to get a more consistent glow that lasts longer.


Yeah, I plan on going over it with my Circuits prof. before assembly, I may even get a variable resistor and set it to another spike to adjust the brightness, depending on how hard the are to get or how hard it turns out to do the spike-knob.

Mindless

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LED / wiring question
« Reply #3 on: December 31, 2006, 03:38:13 PM »
I don't think a battery on a few volts can send out a current that is strong enough to melt plastic or glue. I think a battery is only on a few milliamperes so no danger there.

As for mounting the powerswitch to the LED in a shoulder spike, I'm sure it will work out well.

And as Major said, add a few resistors. Just don't add too much resistance or you wont have any glow at all.

tetsujin

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LED / wiring question
« Reply #4 on: January 01, 2007, 09:54:04 PM »
Quote from: "Mindless"
As for mounting the powerswitch to the LED in a shoulder spike, I'm sure it will work out well.


I wasn't sure if that was what he was suggesting - I think it's a bad idea, though.

Basically, a solution like that is needlessly complex.  You're creating work for yourself with no real benefit.  There are a million places in a HG-size model, let alone a MG-size model, where you can hide a small switch, or a potentiometer, or even just a connector pair you can disconnect when you want the light off.  The plan for turning a Zaku spike into a knob is not one of the simpler ones by a long shot.  The simplest ways to do this all involve finding some out-of-the-way location, something not easily seen.  For instance, you could stash a little thumbwheel pot inside the midriff, extending down to where the hips are - and then access it by removing the side skirt armor.  Or you could stash it inside the back, and access it by removing the backpack.  Or you could stash it inside the chest and access it by opening the cockpit plate.

Now, the problem with the spike plan: you're going to be at risk of making gaps appear around the edges of the spike.  The outward appearance of the spike in the end will depend on how precise you can be with this installation - and I can tell you from experience, unless you have the right tools it's really tough to put an axis on-center and perpendicular to a particular plane.  If you're not on target, then you'll see the part "wobble" as you turn it - it only takes a small error to make the discrepancy visible.

I believe strongly that those who say "it cannot be done" should not interfere with those who are doing it - but I think it's a waste of time.  Think about all the other things you could do, with the model or otherwise, with the time it'd take you to fiddle around with a shoulder spike trying to make it a dial for a potentiometer.

Oh, and of course there's enough room in a MG Zaku head for a LED monoeye.  You can fit an LED just about anywhere.  Just get the right size LED - not those 5mm monsters that are the most common.
---GEC
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