How to combine lighting with portability?

jkiker · Post by **jkiker** » Fri Jun 15, 2012 2:53 pm

Hi all,

I am in the planning stage for a new project. I plan on lighting it, which will be a first for me. My fighter will be inflight, so it will be mounted on some variation of a pole. For the lighting, I would like to run the wires through the pole and have the main power supply in the base. The trick is, I want to have the ability to disconnect the model from the base/mount for portability. I have a couple of RCA size mini-connectors for sound equipment. I thought maybe I could put the female plug in the model, with the male plug at the top of the pole; pull them apart and voila! easier portability.

The question is, can these RCA plugs be used to transmit power? The model will have 3-6 LED's, and while I know nothing about lighting yet, I think one of those low-voltage power supplies in the, say, 5-12 volt range would work.

Or perhaps there is a much better way to achieve the result I am hoping for? I am sure this has been figured out before, so any and all workable ideas are welcome!

Thanks, Jim

Ziz · Post by **Ziz** » Fri Jun 15, 2012 3:49 pm

They can absolutely transmit power. By RCA plug, you mean the ones with the pin in the center and the four shield things around it? If so, you're better off getting a headphone jack set instead - a stereo one will give you two electrical connections to work with (plus ground) so you can have circuits on different voltages running off the same power supply and it gives you a more positive "snap" connection when you put the connectors together.

Scott Hasty · Post by **Scott Hasty** » Fri Jun 15, 2012 4:42 pm

Yep, as stated, go with a headphone (aka phono) jack. 1/8 inch shold be more than enough for most low power requirements.

jkiker · Post by **jkiker** » Fri Jun 15, 2012 4:50 pm

Hi Ziz.

Well, sort of. These came from Radio Shack, and while the plug itself is the same size, it is somewhat longer than a standard RCA plug and there are no shield bits. The package just says "Mono 1/8" Phone Plug." The plastic body screws onto the metal base part, and the base part has two attachment points that are enclosed by the body when the bits are screwed together. That said, headphone jacks sounds like a better idea, although at this point I do not expect to need the setup you describe.

Are there better ways of achieving the desired goal?

Thanks, Jim

Ziz · Post by **Ziz** » Fri Jun 15, 2012 6:31 pm

What's the RS stock number - should be 274-_____?

jkiker · Post by **jkiker** » Fri Jun 15, 2012 8:22 pm

Hi Ziz,

FWIW, 274-286. And that is good to know because...

Ziz · Post by **Ziz** » Fri Jun 15, 2012 8:39 pm

Because I wanted to look it up on RS's site so I could see exactly what you had.

this or this would be your best choices for companion pieces depending on how you need to interface your build to the stand and how the wiring lays out.

jkiker · Post by **jkiker** » Sun Jun 17, 2012 1:09 pm

Hi Ziz,

Yep, I've got the matching female plugs around here somewhere for these plugs. The only thing is, the plastic body of this set of plugs seems rather soft, so I wonder if a heftier-than-usual model would be too much for these things?

In the meantime, I am working up a set of plans, and I think I need to figure out where the plug/wires/possible circuit board need to go before I start cutting out main frame parts. I have started reading more about lighting on the board here; may I contact you directly for some more advice?

Thanks, Jim aka Yoda

Ziz · Post by **Ziz** » Sun Jun 17, 2012 2:11 pm

Don't use the plastic sleeve. Take the metal part out and attach it directly to the kit. The panel mount female jack has a nut that threads onto the end - just drill a hole in the kit and mount the jack into the hole.

For the cable/inline one, the jack usually unscrews from the sleeve - again, drill a hole and put the jack directly into the plastic. You'll have to be really tight with that one though as you only get one shot at drilling the right size hole for the threads to grab properly. Start small and work your way up.

Either way, if you're worried about the size/weight of the ship then do a test build. Tape the major components together and find the balance point. That's where you need to put your display rod/power connection.

jkiker · Post by **jkiker** » Mon Jun 25, 2012 12:04 pm

Hi Ziz and all,

No worries on the balance issue; I'm familiar enough with that. The only thing I didn't quite follow was your recommendation for the stand/cable to be plugged into the model's female end. You said, "...drill a hole and put the jack directly into the plastic. You'll have to be really tight with that one though as you only get one shot at drilling the right size hole for the threads to grab properly." Do you mean drilling a hole to fit the threads (remembering that as I see it, the stand will be a decent-sized brass tube running from the base & power supply, with the male jack at the end to fit into the ship); or, do you mean that the stand piece needs to be threaded to screw into the jack's metal connector?

Back to the lighting, is it possible to use an LED to edge-light a piece of clear sheet plastic? I have the idea to make the instrument panel from clear plastic, say .040", paint the solid areas of the panel, add some clear colors as needed, and attached an LED to the side edge. Would that work?

TIA, Jim

en'til Zog · Post by **en'til Zog** » Wed Jun 27, 2012 2:23 am

Edge lighting instrument panels that way goes back at least to World War II instrument panels. Look for old (old, old) military surplus stuff for samples.

Ziz · Post by **Ziz** » Wed Jun 27, 2012 5:54 am

Here's a pic of the bottom of my AMT KBOP (original release, not R2 repop)

http://farm9.staticflickr.com/8164/7453 ... e162_b.jpg

Female jack mounted to bottom of kit, male jack glued to end of tubing in base. (Yes, that's one of the guns on the base - I need to fix that.)

chiver · Post by **chiver** » Wed Jun 27, 2012 8:05 am

Great idea, I might use this for mine, if I can ever figured out how to light them, I like how now i'd be able to rotate the models from storage to display

TREKKRIFFIC · Post by **TREKKRIFFIC** » Wed Jun 27, 2012 11:33 am

I've used the size K plug and jack from Radio Shack on a few of my models:

http://i146.photobucket.com/albums/r259 ... erplug.jpg

http://i146.photobucket.com/albums/r259 ... erjack.jpg

They only allow positive and negative connections but so far that's all I've needed for my builds.

For my last two builds I actually built them with onboard batteries; perfect for flying around the room!

bradb667 · Post by **bradb667** » Sun Jul 01, 2012 2:24 am

jkiker wrote:FWIW, 274-286. And that is good to know because...

Maybe it doesn't matter in this case, but if you use this jack for power (and the recommended female plugs on the other side), don't you momentarily short VCC to ground during plug insertion and removal?

Might not be a good general-purpose solution for power, especially if a microcontroller is used.

Brad.

jkiker · Post by **jkiker** » Mon Jul 02, 2012 9:26 am

Hi Brad,

Considering that I am pretty ignorant regarding lighting, you are likely correct. On the other hand, I am thinking about having a three position switch, so I can select a battery, wall wort, or completely off; if I turn the power off, wouldn't the issue you describe go away? If not, it sounds like it would be "back to the drawing board" for me.

Do you have further recommendations for how to go about this?

TIA, Jim

bradb667 · Post by **bradb667** » Wed Jul 04, 2012 12:20 am

Hey Jim-

I'd think a switch could resolve the issue, sure.

Really I didn't mean to imply doing this wouldn't work - I see photo proof in this very thread that seems to show it works fine.

But as an example... say you were powering a Jupiter 2 off batteries and had the core effect running. Plugging in external power might cause the microcontroller to reset and ruin the visual effect.

I suspect this won't ever be a real issue for lighting a kit like it would be for a LiPoly powered GPS data logger or something, and even then it's more likely annoying than anything else.

I just thought I'd mention it in case somebody reads the thread later and gets the idea that an audio jack makes a great generic external power plug - I don't think it does. I'd be more inclined to use the other style jack shown in this thread.

Sorry to worry you for nothing,

Brad.

jkiker · Post by **jkiker** » Wed Jul 04, 2012 12:33 am

Hi Brad,

No worries, Sahib; your point was valid and I appreciate the input. Being a lighting green bean (newbie), it is all a big minefield for me so the more I can learn from folks like you who actually know what they are doing (and including a tip of my hat to Ziz), the less likely it will be for me to screw this up!

Thanks, Jim

Styrofoam_Guy · Post by **Styrofoam_Guy** » Wed Jul 04, 2012 1:16 am

If you put an on-off switch in the base then there should be no power running up your plug when you plug and unplug your model.

bradb667 wrote:
jkiker wrote:FWIW, 274-286. And that is good to know because...
Maybe it doesn't matter in this case, but if you use this jack for power (and the recommended female plugs on the other side), don't you momentarily short VCC to ground during plug insertion and removal?

Might not be a good general-purpose solution for power, especially if a microcontroller is used.

Brad.

jkiker · Post by **jkiker** » Mon Jul 09, 2012 9:06 am

Hi all,

First, thanks for all the input so far; now I would like to tap the collective for more specifics. This project is a Y-wing in 1/48 scale and it will be a two seat layout. I plan to light the engines and add some lighting to the cockpits, including the instrument panels and some console lights via fiber optics. I think two superbright white LED's for the engines will work, although there seems to be a range of lights I might use. As a result, I am confused and could use some additional input. Remember too I am a lighting newbie, and for now I am not planning an extensive lighting project for everything I do. This is closer to being a one-shot, at least for now!

I think I will want to use a 12 volt regulated DC wall wort and a 9 volt battery source, using a three-position switch in the base. I will use a mated pair of stereo headphone plugs for power, so that I can disconnect the ship for transport. I think I'll need a small circuit board in the model to regulate power to the LED's.

I think I can use 30 AWG wire wrap wire, which I understand does not require soldering. I tend to over-build, so I find myself wondering if the wire-wrap technique can/needs to be augmented with CA or something... I also want to "de-rate" the LED's a bit to give them a longer life. I'd like for the engines to be bright enough to throw light/shadow on the vectrals, but not be blindingly bright, and I'll use white lights for the cockpit and add color as needed for the few scattered fiber optic lights. Given all this, what specific LED's, circuit board, resistors, etc. would be required? And what have I missed?

Thank you very much in advance for any light you can shed. :-)

Jim

jkiker · Post by **jkiker** » Wed Jul 11, 2012 9:38 am

Hi all,

Upon further review, I think I will use 4 AA size batteries in a clip for that side of the power, and a 9 volt regulated wall wort for the plugged-in power instead of the 12 volt. What I am reading suggests 9 volts should be plenty.

New question: can I use a resistor with each LED and not need to use a circuit board? Or, would running the power through a small board be better? I plan on making the two superbrights in the engines to be removable, but the LED's in the cockpit will likely not be removable unless I build in a removable section to get at them.

Thanks, Jim

Joseph Osborn · Post by **Joseph Osborn** » Wed Jul 11, 2012 10:39 am

Jim, I think you should match your battery power to your wall transformer side, i.e. 6 volts of batteries in 4 AA batteries matched to a 6V transformer. There's no need to put any kind of board in your model unless you just really want to, and it seems like you should be able to run the whole model on just three white LED's by using one of them for the cockpit with fibers and the other two for the engines. You can use transparent paints to tint the various lights in the cockpit. This simple arrangement would be an excellent lighting project for a beginner.

jkiker · Post by **jkiker** » Wed Jul 11, 2012 1:52 pm

Hi Joseph,

Thanks for the input; I am trying to read up on this, and your post reinforces my thinking; that is, that for a simple lighting situation like this (no blinking, sequencing, etc.) that I will be able to use an appropriate resistor for each LED. I do think, however, that I'll use four lights; the two man cockpit can, I think, use two LED's, though obviously not as powerful or bright as the engines, both for the main instrument panels and the console lights.

And a follow-up question for anyone: I think I'd like to use a couple of 5mm superbright whites for the engines; am I right in thinking that I should use a narrow beam type, say 15 degrees? Or something with a wider cone of light? And just how bright should these be, given that I want enough light to cast shadows in the vectrals, but not enough to blind anyone? In other words, bright enough to be visible in a normally-lit room?

Thanks and cheers, Jim

Joseph Osborn · Post by **Joseph Osborn** » Wed Jul 11, 2012 3:14 pm

Simpler is almost always better when it comes to lighting a model. For engine lights, I like to use some kind of diffuser to shine the LED against; the wider the angle of the LED means you can place it closer to the diffuser if space is an issue. To just put an LED shining out of the engine tube sort of looks cheap to me. A diffuser could be something as elaborate as a piece of theater gel, or as simple as a piece of clear plastic sheet that's been scuffed with fine sandpaper. If you use a superbright white, you can dim it a little with a bigger resistor if you deem it too bright.

jkiker · Post by **jkiker** » Wed Jul 11, 2012 4:02 pm

Hi Joseph,

Actually, I quite agree about shining a naked light out the back end of a spaceship. I had planned on using a clear plastic disk, sanded, as a diffuser; what I had not thought of is that the viewing angle of the LED will make a difference if the diffuser is mounted fairly close to the LED. So; I was thinking of mounting the diffuser about 1/2" from the LED in the back end of the engine, with an exhaust cone that extends about another 1/2" beyond that. Can you recommend a good viewing angle (proper term?) for the LED for such a setup?

TIA, Jim

southwestforests · Post by **southwestforests** » Sun Aug 26, 2012 4:11 pm

Is a ways off from happening yet - maybe October - this is good info to have since for first time ever I'm going to mount lighted model on a stand with power frm the stand.

Mr. Engineer · Post by **Mr. Engineer** » Sun Aug 26, 2012 9:22 pm

jkiker,

IMHO, 12volts is a bit too high for a few LEDs. You might want to try something lesser, like 6 volts. Also, the weight of the model would be quite heavy due to the amount of batteries needed to make up the 12volts.

Also, you mentioned a combination of 12volt wall wort and a 9volt battery. Are you doing a relay system where with the absence of the wall wort, the battery will kick in?

jkiker · Post by **jkiker** » Tue Aug 28, 2012 7:26 pm

Hi!

Well, over the last couple of weeks, I have continued to learn and I have purchased a regulated 6 volt power supply; the output will match the 6 volts available from four AA batteries. The batteries and the hook-up for the power supply will all be contained in the base; I have a three-position switch that will allow me to run either the batteries or the power supply, or have both off. I wanted the flexibility to display the model with lights even if no wall power is available. And since the voltages are the same and both cannot be "on" at the same time, I do not think I will need relays or other electronic components.

I had thought about putting batteries in the model, but weight is a consideration as is arranging it so they can be removed and replaced, not to mention some kind of switch so the lights do not get power from both the batteries and the power supply at the same time!

I hope this explains where my lighting design, and my head, are at. Questions? Have I missed something? Let me know!

Cheers, Jim

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How to combine lighting with portability?

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