Installing a LED in an MG's head

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Koshernova
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Installing a LED in an MG's head

Apologies if there is a thread about this. I tried searching the forums for it, and tried Google and other message boards, to no avail.

I recently got the MG Turn A, my dream MG that I never thought would be released... looking at the way the head is set up, it's crying out for a LED to be installed there. Trouble is, I have no experience with LEDs except the ones kits are designed for already.

Can anyone point me towards a tutorial for putting LEDs on an MG's head, or better yet, on the Turn A in particular? I have the ambition of combining this with a tutorial I saw, about powering it with a USB cable instead of a battery.

Thanks!
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ScornMandark
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Basics of working with LEDs

Calculator to determine what resistor you'll need

(links found on Michael Fichtenmeyers LED tips page)

As for the actual insertion of leds into the head? the trick is finding where in the head you've got the space for the lights. Sometimes you can get away with one bright LED the fills the head cavity with light, and you're done. Sometimes, you need to either get multiple smaller lights or clear out some of the obstructions to get the light to come out all the right places.

However you decide to stick in the LEDs in the head, You'll need to run wires into the torso where your battery compartment/USB hookup is for the power. You may also want to wire in your resistors in the torso, just because there's more room there than in the head. One method is to use thin, flexible wire (enamel coated "magnet" wire is good - it's used in windings of electromagnets - found at your local radio shack or equivalent). The wire can be threaded down the neck or between seams, and only a small hole need be drilled to acommodate them.

Alternately, you could do some serious surgery and replace the neck with something like a headphone mini-jack. If you're not planning on taking the head off much, this might be too much trouble.

Also, you will want to consider masking the inside of the head as well. If you get a decently bright LED and don't coat the inside of the head with an opaque layer, the head itself will glow along with the eyes! Amusing, but generally not the effect you're going for...

Hope this helps, as this is what I do when LED'ing my models. If you would like some examples of other models I've LED'd, I can get some pictures when I get back home tomorrow night.
The Mekton Zeta Mailing List wrote:27. I will not put emergency destruct devices in my mecha. I will put them in my pilots. Nothing motivates like thermite.
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Koshernova
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Thank you very much, ScornMandark! Those tips and links help a lot. If you have any pictures lying around, I'd love to see them!

I am probably going to paint the model, most likely a couple of coats of spray paint and a gloss coat. So, I reckon I won't have the problem you describe of the whole head lighting up :)

EDIT: What do you suggest to do, in case the LED dies? Have you had this experience, and what have you done in that case?
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ScornMandark
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Assuming Ike lets me out of Houston by 1, I'll get some photogs tonight :)

As for the LED burning out, to be honest it shouldn't happen, basically ever. If you follow the instructions for using a limiting resistor, your LED should last upwards of 20 years. Plus, its cool to the touch, unlike incandescents :) Basically, if the LED doesn't smoke when you turn it on, you're golden.

The biggest trick is to make sure your resistor is sized properly. USB ports are rated at 5 volts, and the LED package will say on it what the current and voltage requirements are. Either use the resistor calculator in the links above, or use the simple formula below:

5 volts - LED volts = resistor volts

Resistor volts / LED current = Resistor Ohms



for example:

5v - 2.8v (pretty typical LED volts) = 2.2v for resistor

2.2v / .020 Amps (20 mA, typical LED current) = 110 Ohm resistor.


These are typical numbers, make sure to use the actual numbers from your particular LED (or set of LEDs).


If you use several LEDs, make sure to set them up properly. If you use a few in series (connected together in a line), they all need the same current draw and their total voltage needs to be less than 5v.

If you use them in parallel, each LED needs its own resistor.


Hopefully that makes sense, and I'll try to get some pictures up tonight :D
The Mekton Zeta Mailing List wrote:27. I will not put emergency destruct devices in my mecha. I will put them in my pilots. Nothing motivates like thermite.
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ScornMandark
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Wiring and power of a 1/60 Big Scale Real Detail Strike Gundam.

The test subject. I actually wired this guy a few years back. I had planned on sort of finishing him, and never got around to it (like most of the things I'm going to get back to :P ). Instead, he'll be a good wiring example.

Closer up. This is a good example of checking your model head for light cracks. It's easy to overlook little pinhole spots that light'll come out of, so keep an eye on those.

Plugged in. I didn't use a USB cable, I used a battery pack. Same principle applies, though.

Unplugged. One important part of wiring the mech, especially for external power supplies is finding an inconspicuous spot for wiring in the connection. Assuming you're doing a 1/100th scale, you could use a mini-USB connection, or wire the usb cable to a stereo mini-jack. I used a connector I scavenged from work for the main power supply, and stereo mini-jacks for some of the other connections.

The head. I decided to use a removable connector because I was using it for a short stop motion thing in which the head gets popped off. Plus, it makes it easier to wire, since you're not fighting the wires while assemblingthe head and body etc. This might be especially good in your case, since you would be able to paint the head seperately from the body.

The inside of the head. Sorry its a little fuzzy, I don't have a good macro on my camera... Anyways, the whole head is lit by one Bright White LED. (~4000 mcd) I situated it in the head pointing forward, and tinted the eyes and sensor plate with Sharpie Markers. You may want to use a particular colored LED (like yellow) and just mask the eyes, letting the yellow come through. Your choice. If you want multiple colors from one LED, you need to use a white LED since that's the only one that actually has multiple colors in the output. If you put a yellow LED behind a red filter, no light will come out. You have been warned :)

The connection in the neck. I had to remove the neck joint entirely to make room for the stereo jack. Fortunately, the 1/60 "Big Scale, Real Detail!" models have a lot of hollow space.

Here is the junction of all the wiring in the torso. I put the resistor here, as well as branching wires to the backpack connector and both arms. One with the flash, to see if I could get any clearer of a picture.

Wiring schematic. This is basically how the circuit is wired electrically. The dots are where the wires actually connect to each other. I put the resistor for the light in the head in the torso; if you don't have much room in the head to work with this might be a good space saver option. There are several branches off to the left hand side of the drawing. These are where I wired in other things as seen below:

I ran the wire through the shoulder, down the arm, into the hand, and into contact pads on the hands. Then, individual weapons could have matching contact pads and be powered through the hands. Neat...if id had worked :P The wiring was good, it's just hard to get a good connection via a contact pad.

So, I went back in and installed a connector in the back. Another stereo mini-jack, to provide a semblance of modularity for whichever pack I wanted to attach.

I decided to use the Launcher Pack. It was big and open, and just asking for one, really.

The connector in the pack. It fit in pretty nicely, although I had to do a little finageling to get it lined up so that the pack would just plug in as normal.

You can see the early attempt to use the hand connector. It worked ok, but usually I had to press the hand into the handle pretty hard to get a solid connection. Not exactly the "throw the switch and forget about it" I was going for.

The circuit for the gun. Note it is nearly identical to the head, but since it's designed to be modular I didn't want to tie the power connection to a specific setting. So, the connector outputs 9v, just like the battery pack, and any current/voltage limiting is in the weapon pack itself. Plus, since the gun is so big and empty, there was lots of room for resistors etc.

Holding the gun, unplugged. I think that having a plug-in-able power source is better than an internal battery, just in that you don't have to crack open the model to change the battery. On the other hand, you need to run a cord to it.

Plugged in.

Plugged in, rear view. Here's where choosing a good location for your power plug comes in handy. Note it is below the backpack completely.

Powered up!

Firing at the camera! A little bright for the camera, but you get the idea.

Hope all this helps! I've got a few other models that I can get pictures of. Also, I'm planning on building another new MG in the near future, and I can do a more in depth, step by step if ya'd like.
The Mekton Zeta Mailing List wrote:27. I will not put emergency destruct devices in my mecha. I will put them in my pilots. Nothing motivates like thermite.
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MarkW
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You might want to look at my page as well--I've lit several, from 144 to MG, and they are all basically the same idea. You might find some different angle pics to help out (especially on the Sazabi page).

http://mysite.verizon.net/modelwerks/ti ... Primer.htm
http://mysite.verizon.net/modelwerks/ms ... n_Eyes.htm
http://mysite.verizon.net/modelwerks/ms ... ks/GFT.htm
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Meteoid
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I attempted to light a 1/60 big scale Gundam Exia on battery power, it zapped the batteries too quickly though, probably because I was trying to light the head, the GN Drive and the chest Orb. Is there a way to make a rechargeable light up Gundam?
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ScornMandark
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A couple of things could have happened there. Assuming you're using LEDs, what kind of batteries are you using? How are the LEDs wired - series or parallel? Are you using a current limiting resistor?

3 LEDs in parallel would draw ~60 mA, which ain't a lot...unless you're using a button cell batter (like a watch battery). Those are good for driving a single LED, especially if you use a bigger resistor to under-drive the LED. Watch batteries tend to run ~50 mA hours: 50mA for 1 hour, or 1 mA for 50 hours. So, a 20 mA LED will run for 2.5 hours before running out. AA batteries, on the other hand, tend to run about 2800 mA hours. A 20mA LED, if left on 24/7, will run for nearly 6 days (140 hours of run time). Assuming you turn it off most of the time, you'd be fine for quite a while.

If you want to make a rechargeable gundam, you'd need to put in rechargeable batteries and provide a connection to the recharger to plug it in. At which point, you might as well just make it a plug in connection and skip the batteries altogether. Radio Shack or other local electronic stores sell wall transformers in assorted voltages, typically 3, 6, 9, 12, etc. These plug into a standard outlet like the transformer on phone chargers, laptop cords, and most other electronic equipment. You can buy a socket to install into the model and the transformers come with assorted connectors to fit different socket sizes.

If you really like the portability of the batteries, consider installing larger (AA, 9V) batteries in a base of some kind and running the connection up into the model from there. That way, you can swap out the batteries easily (and you can use standard rechargeable ones to boot!).

If you're really dead set on having the rechargeable batteries in the model itself, you'll need to provide a connection from the + end of the topmost battery and the - end of the bottommost battery (assuming - is on the bottom). You can then tie the + end to the + side of a voltage matched transformer (like the ones mentioned above) and the - side of the batteries to the - side of the transformer. So, if you have 2 AAA batteries in series, you've got a total voltage of:

1.5V + 1.5V = 3.0 V

Using a 3V transformer, you can leave it plugged in when you're by an outlet, and when you unplug it, it'll run itself off the batteries until the batteries run down (at which point you plug it back in). See circuit below:

Rechargeable Diagram

Hope this helps!
The Mekton Zeta Mailing List wrote:27. I will not put emergency destruct devices in my mecha. I will put them in my pilots. Nothing motivates like thermite.
DylanB2010
Posts: 1
Joined: Wed Sep 28, 2011 4:58 am

Re:

ScornMandark wrote:Basics of working with LEDs

Calculator to determine what resistor you'll need

(links found on Michael Fichtenmeyers LED tips page)

As for the actual insertion of leds into the head? the trick is finding where in the head you've got the space for the lights. Sometimes you can get away with one bright LED the fills the head cavity with light, and you're done. Sometimes, you need to either get multiple smaller lights or clear out some of the obstructions to get the light to come out all the right places.

However you decide to stick in the LEDs in the head, You'll need to run wires into the torso where your battery compartment/USB hookup is for the power. You may also want to wire in your resistors in the torso, just because there's more room there than in the head. One method is to use thin, flexible wire (enamel coated "magnet" wire is good - it's used in windings of electromagnets - found at your local radio shack or equivalent). The wire can be threaded down the neck or between seams, and only a small hole need be drilled to acommodate them.

LED watches is quite beautiful and colorful. there are all kinds of LED watches. Looking for LED watch supplier? DGPal store can supply all kinds of high quality and fashion wholesale LED watches at good price.

Alternately, you could do some serious surgery and replace the neck with something like a headphone mini-jack. If you're not planning on taking the head off much, this might be too much trouble.

Also, you will want to consider masking the inside of the head as well. If you get a decently bright LED and don't coat the inside of the head with an opaque layer, the head itself will glow along with the eyes! Amusing, but generally not the effect you're going for...

Hope this helps, as this is what I do when LED'ing my models. If you would like some examples of other models I've LED'd, I can get some pictures when I get back home tomorrow night.



Thank you very much, ScornMandark! Those tips and links help a lot. If you have any pictures lying around, I'd love to see them!
Umsden
Posts: 2
Joined: Fri Aug 03, 2012 11:12 pm

Re: Installing a LED in an MG's head

Koshernova wrote:Apologies if there is a thread about this. I tried searching the forums for it, and tried Google and other message boards, to no avail.

I recently got the MG Turn A, my dream MG that I never thought would be released... looking at the way the head is set up, it's crying out for a LED to be installed there. Trouble is, I have no experience with led tubes except the ones kits are designed for already.

Can anyone point me towards a tutorial for putting LEDs on an MG's head, or better yet, on the Turn A in particular? I have the ambition of combining this with a tutorial I saw, about powering it with a USB cable instead of a battery.


Thanks!
I took assitance of my expert mechanic and my LED lights are working well.
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