# My Deus Ex: Human Revolution-inspired candelabra project



## seanspotatobusiness (Jul 27, 2012)

I have started a project to imitate the candelabra featured in the computer game Deus Ex: Human Revolution. The candelabra looks like this: http://imgur.com/a/BUQ8D#1

I'm having some trouble implementing my project, specifically with the diffusion of light. See below for a bad representation of my plan.

I'm using frosted 38mm diameter acrylic tubes and my original plan was to insert a metal tube holding a strip of 5050 RGB LEDs. However, despite the frosting and even addition of light diffusion "gel" (plastic sheet) inside the tube, points of light are clearly visible. One possible (long-shot) solution I read was to insert clear beads in the space between the LEDs and the outer tube, which may or may not diffract the light sufficiently.

Alternatively, I could use an RGB power LED such as the one here but the viewing angle is quite wide and I'd suppose I would need an optic which I am unable to locate for this LED.

The wiring will not be hidden but will be braided and decorative so that it doesn't look out of place.






Click to enlarge:


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## rock_007 (Jul 27, 2012)

Interesting project, first of all to say, you want to imitate the candelabra in a computer game, seems interesting. Try to get some help from the internet if you can regarding the query. There is no display of image on link 2 i.; the (one here) link. Try to find an optic for your project if available on the Internet.


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## blasterman (Jul 27, 2012)

The issues you are dealing with are the same ones DIY light saber makers have to deal with. More specifically, the issue with LEDs killing the illusion of a diffuse rod because of hot spots. A suggestion to approach the problem from that angle first. I know a lot of those guys have solved it.


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## RoGuE_StreaK (Jul 28, 2012)

As per blasterman's reply, but not just DIY; the cheap Hasbro lightsabers use a white polyethylene foam tube as a diffuser, and I know others have used this method. Not sure where you can find this as I've never looked for it, but white _rod_ polyethylene foam (ie. no hollow in the middle) can be found in many hardware stores as foam sealant strips for doors etc. DIY NERF people use it to make their own foam darts.

Here's a look at the lightsaber thing on Park Sabers: http://www.parksabers.com/Blade_Anatomy.html


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## seanspotatobusiness (Jul 28, 2012)

Hi. Thanks for all the replies. Regarding the foam tubes, I see the Hasbro design uses multiple small LEDs. I'll keep this as an option but since I would like to be able to change and tune the colour, I want to use RGB LEDs and it would be such a chore to solder so many leads. I imagine that the foam severely attenuates the luminosity of the LEDs as well?

There are many DIY light sabres which use power LEDs and collimator lenses so I think I'm going to attempt this route next. Can anyone suggest good value suppliers to the United Kingdom (I'll see if I can find any on this forum)?

I should also say that I'm hoping to use one of these controllers, designed for LED strip lights, to power the LEDs. I'm pretty sure that for most RGB power LEDs, I can wire three in series and connect directly to the controller, as though it was an LED strip.


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## RoGuE_StreaK (Jul 28, 2012)

Maybe you could use a tight-angle TIR (total internal reflection optic, think of them as kinda part reflector part lens), I got some bits shipped from LED Rise and they came from Romania, so kinda local for you and I believe it would be free shipping.
You haven't said how long or thick the tube is, from the 38mm OD I'd guess from the pics it's maybe 250mm long? Shouldn't be as much issue with fade-out along the length for you if you use base illumination.

Not sure about the controller, generally around here anything refered to as a "power" LED is considered to be more reliant on a constant current rather than a constant voltage, but that's probably going a bit overboard for your application. Find out what the Vf (forward voltage) of the LED is (or should roughly be), how much current (roughly) is required, then feed that into an LED calculator and grab a resistor to match the results. Your source driver is 12V, so for example if your LED Vf is 3.5V and current is 350mA, you'd need a resistor to suit a voltage drop of 10.5V (3x LEDs) and 350mA, with a supply of 12V (that one looks like it can do up to 2A, so that's fine); resistor for such a case would be 1Watt 4.7Ohm.

http://led.linear1.org/1led.wiz/


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## seanspotatobusiness (Jul 29, 2012)

Hi Rogue. Thanks for your advice; I really appreciate it.

The tube is 38 mm outside diameter, 35 mm inside diameter and 300 mm length. Indeed you're right; I won't want as tight an angle of collimation as those making light sabres. Any idea what angle I should try first? My guess is 25 degrees.

Regarding the resistors, the main (only?) reason I want to wire it up in series (I guess I will need separate cathodes/anodes for blue/green and red for that to be possible) is to avoid heavy energy loses in resistors. One watt per colour per LED comes to 9 W of wasted energy and problematic heat! If I can get them in series, I think I'll only need to drop 2.5 V with 350 mA for blue and green and maybe 1 V for red. I expect that I may use these (I've ordered one to test).

I will need to investigate the above pictured controller. I only measured the voltage when it was disconnected - I don't know whether it regulates current or voltage.


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## RoGuE_StreaK (Jul 30, 2012)

Actually I don't know if those controllers would regulate _anything_, pretty sure they'd just PWM each line. It says input/ouput: 12V. Also make sure you take note of whether it's "common cathode" or "common anode", this will dictate which pins you need to tye together. Come to think of, you NEED common cathode if you are dealing with a "power LED", as these only have one cathode and three anodes, whereas the 5050s have indiviual cathodes and anodes for each colour, and can be set up either way.

Honestly with the distance you are dealing with, I'd just say "experiment"! Get some power LEDs and put them at the base, see how well or badly the light shapes. You could then try something like a ping-pong ball as a diffuser, experiment sanding it in various places to maybe diffuse it more or thin it down to allow more light through... yes you are drastically losing light rather than trying to reshape it, but I think if you have a bright enough source it won't matter a damn at such short distances. You could spend forever trying to model the beam patterns, calculating to the inverse-square law, etc.

[EDIT] Ah just checked your LED link, those ones have individual cathodes, so ignore my comment about power LEDs


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## Gunner12 (Jul 30, 2012)

What about electroluminescent stuff? You could try wrapping white electroluminescent panel around something, or a few white electroluminescent wires in a white plastic tube. This will decrease the hotspots of LED and will not require a TIR optic or a diffusing tube. If your TIR and diffuse tube is not matched well, you could end up with one end of the tube being brighter then the other.

White uelectroluminescent is pink when unpowered though, so that might not work for your project, and I don't know hot bright they are and if they are useable for actual lighting.

Best of luck with your project!


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## AnAppleSnail (Jul 30, 2012)

Gunner12 said:


> White uelectroluminescent is pink when unpowered though, so that might not work for your project, and I don't know hot bright they are and if they are useable for actual lighting.
> !



Rarely useful for useful light beyond indicator lines.

I suggest: Get 3 RGB strips in a triangular prism, put white foam around them, and call it a candlestick. You'll need all your usual controller-type stuff hidden, but this conceals the wires inside the light diffuser. White foam passes a fair amount of light, especially if you get the kind without TiO added to whiten it.


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## seanspotatobusiness (Jul 30, 2012)

Hi. I did consider electroluminescent stuff but both the light output, lack of colour customisation and the expense led me to ultimately choose LEDs. I think electroluminescent panels would look pretty sweet nonetheless.

AppleSnail, I'm not sure what you mean re: the triangular prism... would the LEDs be facing into the prism or away from it? Are they inside it or out?


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## AnAppleSnail (Jul 30, 2012)

seanspotatobusiness said:


> Hi. I did consider electroluminescent stuff but both the light output, lack of colour customisation and the expense led me to ultimately choose LEDs. I think electroluminescent panels would look pretty sweet nonetheless.
> 
> AppleSnail, I'm not sure what you mean re: the triangular prism... would the LEDs be facing into the prism or away from it? Are they inside it or out?



My (white) LED strip lights are about 8mm wide. Imagine cutting a bar from triangular stock with 8mm faces. Glue the LED strips to the sides this bar (Which serves as a heat spreader) and stab this into the center of your foam 'candle' shapes. Attach wires in secret and you're halfway there.





Crude drawing of RGB LED strip being applied to one face of a triangular metal bar stock.


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## seanspotatobusiness (Jul 30, 2012)

Hey Apple. Thanks for the schematic! Unfortunately, I don't think it will work for me. I've currently got an RGB strip wrapped around a metal tube. I wrapped some packaging foam (this sort of stuff) and the spots are still clearly visible. In fact, while the spots are dimmer, I'm not sure that the gaps between them are actually brighter (I've got half of the length with foam and half without). I'm going to use the tube/strip in some other application where I will have a larger distance for the light to diffuse.


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## AnAppleSnail (Jul 31, 2012)

Try carving styrofoam? It's far more isotropic. I find the soft foam rolls don't diffuse as well as I thought.


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## RoGuE_StreaK (Jul 31, 2012)

Actually sean you haven't mentioned what the LED spacing is on the 5050 strips? I've seen plenty that have big gaps between them, no matter how you try to diffuse it you won't be able to overcome that, you need tight spacing to begin with.
If you do have the ones with large gaps, perhaps there could be a way of wrapping them so two strips cross each other diagonally in such a way as to fill the gaps in one with the LED of another...

As a side thought, to try to diffuse multiple spots, you'd want to place the diffuse material far enough away from the LED so that it is catching overlapping pools of light from the neighbouring LEDs, rather than having the diffuser hard up against the LED, which will just give you a diffused spot. Perhaps also you could experiment with adding a dollop of clear caulking silicone over each LED, it may possible act as a dome lense and give a larger angle of emission? (or it might do the complete opposite, hence "experiment")


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## seanspotatobusiness (Aug 1, 2012)

Okay, I'll try it next time I get my hands on some (will ask friends to save any Styrofoam they get) but I imagine it will severely attenuate the light.

The LEDs strip is the highest density I could find (120 per metre for RGB). Unfortunately, the circumference of the pole leads the LEDs to almost be in a line. There are four lines running up the pole. In retrospect, I could have avoided that by wrapping two separate strips up the pole and aligning them out-of-phase.

As well as the acrylic tubes already being frosted, I inserted a few layers of diffusing plastic sheet. There isn't enough space in the tubes for other items to not be pressed up against the LEDs. Although I will try the Styrofoam, I'm expecting I'll have to use the strips for something else and wait for the power LEDs to arrive. The strip I already adhered to a pole, I will use in a frosted vase of 10 cm diameter. I think the extra 3 cm all around will make a lot of difference, plus the glass is more heavily frosted.

Incidentally, I noticed that my aluminium pole got very (skin-damagingly) hot after about 15-20 minutes power. I will need to ensure that the pole is connected to some metal which can better dissipate heat to the environment.


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## yliu (Aug 10, 2012)

Can't you just put high power emitters on the bottom of the frosted tubes, so it will be like a flashlight with a traffic wand?

Look up "Philips LivingColors", maybe you could also fit Red, Green and Blue colored dies on the bottom, then you could make all the colors you want and the tube should light fairly even.


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## seanspotatobusiness (Aug 12, 2012)

Hi Yliu. Indeed, that is the method I'm attempting now.

I'm stuck trying to solder the copper rod heatsink into place. I need a thermal connection between the LEDs and the candelabra and this is my solution:






The problem is that I'm unable to melt the solder/keep the candelabra heated/heat the copper rod. I've tried using a regular soldering iron to maintain an elevated temperature combined with my soldering gun (which is only meant to be switched on 12 seconds in every minute). I also try using a mini blow torch (about the size of a large permanent marker pen) but the flame keeps going out, presumably because it's upside down and getting blown out by hot oxygen-depleted air).

Edit: forgot to say that 45, 30 and 15 degree collimators were not sufficiently tight enough. I have ordered 5 degree ones and expect them in a couple of weeks.


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## yliu (Aug 12, 2012)

Maybe you can use the thermal glue or whatever it's called, it is used to glue the CPUs to their heat sink.

Good luck.


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## RoGuE_StreaK (Aug 13, 2012)

How are you attaching the LED to the copper rod?
Is the candelabra cup intended as an extended heatsink, or is the solder purely as an attachment method? Can you perhaps place the cup on a hotplate if soldering is a must? Or could you just drill through the cup and tap a screw into the copper?


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## AnAppleSnail (Aug 13, 2012)

seanspotatobusiness said:


> I'm stuck trying to solder the copper rod heatsink into place. I need a thermal connection between the LEDs and the candelabra and this is my solution:
> 
> 
> 
> The problem is that I'm unable to melt the solder/keep the candelabra heated/heat the copper rod. I've tried using a regular soldering iron to maintain an elevated temperature combined with my soldering gun (which is only meant to be switched on 12 seconds in every minute). I also try using a mini blow torch (about the size of a large permanent marker pen) but the flame keeps going out, presumably because it's upside down and getting blown out by hot oxygen-depleted air).



Arctic Silver thermal epoxy is also epoxy. Regular 10-ton epoxy in thin layers is reasonably thermally-conductive. My brazing torches run in most any position EXCEPT inside a bottle-shaped object. If you do not trust Arctic Silver, then you'll have to heat the base to puddle solder. Then use needlenose pliers you despise to hold the copper slug as you heat it quite hot. Press this onto the solder while heating the top of the copper slug. Once it sets, remove heat and hold it in place. Or use your second needlenose pliers and apply ice to quickly cool things. This will hiss and steam excitingly. You should probably not breathe the steam (Explains a lot about me, eh!?). Then attach LEDs and wires. I've made custom copper housings out of pipe and sheet copper this way.


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## seanspotatobusiness (Aug 13, 2012)

Hi. Thanks for all the responses! The use of solder is intended to thermally couple the LED to the candelabra via the copper rod. Due to the construction of the first candelabra I'm using, it will not be possible to drill and tap but I might try this for the second!

The LEDs will be attached to the copper rod using epoxy on the sides but with the interface filled with cheap white thermal paste.

Having looked up the thermal epoxies, I notice their conductivity is 0.7-1.0 W/(m.K), compared to 0.3 for regular epoxy (about 400 for copper). I'm not sure they're worth the additional expense.

I don't have a hot plate but I could maybe use the gas hob. I won't, unless the following plan fails, because I'm afraid of burning myself!

My current plan is to epoxy the rods in place and then to melt solder in the space around the rods using my blow torch with the candelabra at an angle to allow hot air to escape.


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## AnAppleSnail (Aug 13, 2012)

seanspotatobusiness said:


> My current plan is to epoxy the rods in place and then to melt solder in the space around the rods using my blow torch with the candelabra at an angle to allow hot air to escape.



Try with just epoxy, please. Heating epoxy enough will burn it, leading to toxic fumes. I have found that desoldering with a torch is likely to create sufficient temperatures for common epoxy to burn. A thin layer of epoxy with wide surface contact is not much less thermally-conductive than a metal-to-solder connection (Near-zero 'meters' value in W/m*K gives low resistance).


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## seanspotatobusiness (Aug 13, 2012)

Okay, but the problem with using only epoxy is better illustrated in this modified diagram. The shape of the candelabra cup is such that there will actually be very little contact area between the rod and the cup. That's why I think I need something more conductive to fill the gaps. Perhaps I could epoxy the rod in and then just drip solder into place? The joints would be cold and I don't know whether they'd stay in place with the candelabra getting moved around during normal use.


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## bshanahan14rulz (Aug 13, 2012)

If it can't be damaged by heat, you could remove anything that would melt and just torch the copper and the cup until they are hot enough to wet teh solder and then just start feedign it lotsa solder.

Another idea is to have someone custom make you some aluminum sinks that will fit the space, or copper sinks if you can afford them. 

Have you already tested the "optics" you will be using? I'd start there to make sure that a single RGB high power LED will give you the effect you are looking for with little/no color separation.


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## RoGuE_StreaK (Aug 13, 2012)

Grab a file and roughly shape the copper to fit better.


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## hellokitty[hk] (Aug 13, 2012)

Why don't you just try putting the whole thing in your oven?
Just put a roll of solder in there and bake it.

Maybe you'll want to take a look at fx-sabers.com
They look pretty impressive to me :twothumbs Not meant for actual lighting though, but the lightsabers look pretty evenly lit.


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## RoGuE_StreaK (Aug 20, 2012)

Another cheap thing to experiment with for end-lit is cellophane (or whatever unbranded non-cellulose cheap stuff you can find in your local dollar store) - make a tube of it, rolling it say 10 times or more (ie. 10 layers), its bifringent properties combined with multiple layers helps spread the light. To a degree. Worth picking up a role for $2 to play with.


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## seanspotatobusiness (Aug 20, 2012)

I registered on the FX Sabre forum four days ago but they still haven't approved my registration. There is no contact information that I can find. I wanted to ask them about the cellophane since that's what's recommended in a thread in their forum.

Regarding the copper rods; on closer inspection of the cups, I noticed that there is some exposed thread (the cups actually screw onto this particular candelabra). I've ordered a tap and die set but the first one was out of stock and eventually my order was cancelled. I've ordered another from elsewhere and am awaiting dispatch.

Thanks again to everyone for their suggestions. I will update the thread as soon as I make notable progress (or hit the next obstacle)!


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## seanspotatobusiness (Aug 21, 2012)

It doesn't look like I'm getting onto the FX Sabres forum any time soon which is unfortunate because they've surely got an answer for this, but my current problem is the visibility of the outside edge of the diffusion film. I've ordered cellophane and will find out if it's any different from my current sheets.

The photo below shows the issue. Here, I've deliberately cut in various directions in order to break up the line and make it harder to follow but it's still quite clearly visible (the front tube is the one with film in - you can see a jagged line which is the outside edge of the film). 

http://i.imgur.com/zwlwW.jpg



Your image is too large and has been replaced with a link. Please resize and repost.
See Rule #3 If you post an image in your post, please downsize the image to no larger than 800 x 800 pixels. - Thanks Norm


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## AnAppleSnail (Aug 21, 2012)

More layers may help reduce the visibility.


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## seanspotatobusiness (Aug 21, 2012)

AnAppleSnail said:


> More layers may help reduce the visibility.



The problem is that the edge of the outside layer will always be pressed up against the inside of the tube, and therefore be visible.


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## seanspotatobusiness (Oct 15, 2012)

It's been a right kerfuffle, but all the LEDs are in position and connected. The current problem I'm addressing is that the supply I'm using provides 12.5 volts on all three channels. I reach typical current flow through each colour (I think 300 mA) at 9.7 v for blue, 7.4 v for red and 10.7 v for green. To drop, 2.8 v, 5.1 v and 1.8 v, I need 8 ohm, 14.6 ohm and 5.2 ohm resistances inline with the supplies.

I've bought an assortment of 1W resistors and can approximate the required resistance with:

6.8 ohm and 1.2 ohm in series for blue,
3x47 ohm and 1x270 ohm in parallel for red,
6.8 ohm and 20 ohm in parallel for green.

Together, they're dissipating just under 4W. I was hoping they could all be placed in the controller casing (there is definitely enough space) in this picture but I'm uncertain how much heat will build up inside it. Maybe I should locate the resistors outside of that controller?


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## RoGuE_StreaK (Oct 15, 2012)

Those controllers use standard 0.1inch / 2.54mm pins/sockets (headers), you could make a little breakout board that plugs into the line and has a socket at the other end for your LEDs.
Or just unsolder the output cable from the controller board, solder in wires to your breakout board, then solder the original cable to your breakout.
May as well keep the resistors separate, maybe put them in a nice metal box that can double as a heatsink.

Also might need to use 2W resistors.


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## seanspotatobusiness (Oct 15, 2012)

RoGuE_StreaK said:


> Those controllers use standard 0.1inch / 2.54mm pins/sockets (headers), you could make a little breakout board that plugs into the line and has a socket at the other end for your LEDs.
> Or just unsolder the output cable from the controller board, solder in wires to your breakout board, then solder the original cable to your breakout.
> May as well keep the resistors separate, maybe put them in a nice metal box that can double as a heatsink.
> 
> Also might need to use 2W resistors.



Hi. Thanks, Rogue. Would these be suitable, for example? http://www.ebay.co.uk/itm/Latching-...al_Components_Supplies_ET&hash=item1c16bb3b40

If it's attached directly to my strip board, is there a risk of damaging the board when unplugging (do to the mechanical stress on the board).

I'm thinking metal project boxes are expensive for what they are... I might just epoxy the resistors to the underside of the candelabra base. That could work? I could then glue that controller circuit to the underside of the candelabra base and drill a small hole for the IR detector.

My final problem is insufficient collimation of the LED light. I'm using some cheap lenses from China that were meant to give collimation to five degrees but I'm still losing most of the light near the bottom half of the tube so that's definiately not what I'm getting. I realise that using cheap generic RGB LEDs means that I won't be able to find a lens perfectly designed to collimate their output.


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## seanspotatobusiness (Apr 12, 2014)

This project stalled because I couldn't get the ends of the tubes to look right. The tubes are frosted acrylic. For the ends of the tubes, I glued silver mylar film to a clear acrylic cylinder, inserted that cylinder into the end of the tube, sawed the cylinder off and then sanded it down. The result doesn't look very good.





I used rolled-up cellophane to try to distribute the light better but you can see where the edge contacts the tube.





The acrylic tubes I already have are 30 cm (1 foot) long with a 38 mm (1.5 inchs) outside diameter. Has anyone got any ideas on how to terminate the tubes in a way that doesn't look so bad? I might just not terminate them at all.

Here's a picture of the whole thing looking bad. I don't know how to maximise the dynamic range of my camera so the picture doesn't appear how I see the scene. Only the middle tube has the cellophane. I haven't yet put it in the others because I'm not yet happy with the tubes themselves (the ends of the tubes, specifically).





Mk II will probably use a chain of low-power RGB LEDs instead of single high-power ones.


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## seanspotatobusiness (Apr 19, 2014)

I've done what I think I should have done in the first place (but had no idea that it was a possibility until recently) which is contact a couple of people in the UK who make and sell LED-lit Star Wars light sabers. From them I'll buy the plastics including the tips.

Could anyone advise me regarding my next attempt in which I intend to link many low-power RGB LEDs in a chain. 

If I attach all the legs together and each LED consumes 20 mA, a chain of 40 LEDs would consume 800 mA for each colour at 2.2 V (red) and 3.4 V (blue and green) which equates to 7.2 W. That's quite a lot of heat for something that has no mechanism to dissipate it, right? That would only be for one "candle" as well so I'd need to supply three times that. Perhaps I just can't have them at full brightness? Is the use of 5 mm versus 3 mm LEDs a consideration because the specifications I see on eBay make them look the same except 5 mm consumes more space?


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## Ken_McE (Apr 20, 2014)

The LEDs on a stick will give good color control. Three fluorescent tubes standing on end would give a lot more light.


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## seanspotatobusiness (Apr 20, 2014)

I'm not sure what you mean by LEDs on a stick but if you mean what I think, the problem is that the light would have clear points of origin and not be diffused. I think a fluorescent tube would not look right because it needs an electrical connection at both ends.

I'm also thinking that I can't daisy chain 3/5mm LEDs together because the colours won't mix; I'll have distinctive red, blue and green sides for each tube (which incidentally is already somewhat problematic for my single-LED approach).


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## Ken_McE (Apr 27, 2014)

> I think a fluorescent tube would not look right because it needs an electrical connection at both ends.



Google for "fluorescent tube guards". They are clear plastic tubes sized so that a T-12 or T-8 bulb fits in them nicely. Set one on end with a base to steady it and hold it firmly in place. Run a single wire up the side in between the bulb and the holder, have it alligator clip to the upper end of the tube, come up with a decorative cover if you don't want people to see the end. Speaker wire is available with clear insulation, this would reduce its shadow. High brightness, quite close to what you want, low fuss.

Or if you really, really, must have that exact look, set clear tubes on end, saw open a bunch of cyalume sticks, pour the contents into the tubes, enjoy.


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