You can click on the pictures on this page for a larger version.
Here's a how-to of how I created our LED MR-16 spotlight holders. I got a lot of inspiration from this page and on the PlanetChristmas, forums, and would like to thank everyone who helped inspire this project. I decided to change things up a bit, mainly to keep costs down. At least at the big box stores, plumbing fixtures can be expensive. I didn't want to pay $5-10 per light (not including the LED bulb) and figured there had to be a better way to get the same functionality for a lower price.
My main cost-saving trick was twofold: Firstly, I used PVC pipe for the majority of the body of the lampholders. Many of the other options used some sort of PVC fitting instead, which tends to cost $1.50-$3 for the correct sizes. On the other hand, PVC DWV pipe is dirt cheap. I paid $3.50 for enough PVC to do about 48 fixtures. Secondly, for the bottom of the fixtures, I discovered what's called a "rough-in cap" or "test cap", and instead of $1.50 for a pressure-capable schedule-40 fitting, these cost 25 cents each (see below) and seem to work beautifully.
Before we go any further, some disclaimers: As of this writing, these fixtures have not been "battle-tested". I hope they work, and I think they should. If you feel they will not, I'd be interested in having you email me to explain why -- I'd rather uncover a major design flaw now vs. during the display season, and I'd rather not ruin these somewhat expensive LED bulbs. Furthermore, if you follow these instructions, you do so completely at your own risk. I can't be held responsible for anything that comes from anyone attempting to do something with these instructions.
Above, you see all the parts you need to make the basic LED enclosure. The items needed were:
first step is to drill a hole in the side of the PVC pipe, roughly centered, and
thread the carriage bolt through it. Then thread on a nut, and crank it
nice and tight with a wrench. This will pull the square part of the
carriage head into the PVC. For now, you can simply thread the second nut
we take all the plumbing caps and drill a hole in the center of them. I
used a drill press which made it go very quickly -- if you're drillpress-less, a
hand drill works too. I used a 15/64 bit which was about as small as I
could thread the two wires (with the resistor bulge) through easily.
thread a MR-16 socket through the hole, and then secure it with hot glue.
Press down on a hard surface until the glue sets. I then spread the wires
and put a bulge of glue on the bottom as well. We want these puppies
next step is to attach the dome to the top of the pipe. The dome is 1/2 of
the acrylic ornament. Carefully remove the hanging loop from the
ornament-half, then run a generous bead of hot glue along the top of the PVC
pipe. As fate would have it, the 60mm ornament lines up almost perfectly
with our 2" DWV pipe. Once that set up, I ran another generous bead
of glue along the outside seam. Again, we want these puppies to shed water
like a good hunting dog. At this point, you can attach the bulb if you're
will now create the L-brackets which will support our lights. One can buy
L-brackets, but they're expensive (at least $1 a piece) and we'd have to drill
our own holes in them anyway. To do this "cheap but effective"
we'll need to make our own. To do this, I used aluminum bar stock,
available at Home Depot for about $5 for a 4' length. Each fixture needs
4" so you can get 12 fixtures out of one such bar-stock. I used
aluminum because it's corrosion-proof, looks nice, and easy to work with.
If you're willing to put up with steel, you can get by about 20% cheaper.
You can also no doubt find a cheaper source than Home Depot, but I wasn't
willing to chase all over town for the volume I needed. As noted above,
you want to cut each piece to 4" long. I lack a good power tool for
doing this, so I used a crappy old miter box with a hacksaw.
you want to drill a 1/4" hole in both ends of each piece. Drill it as
close to the end as possible, but far enough so that there's enough metal on all
sides of the hole to be strong. If you have a drill press, it's worth the
time to set up a positioning jig, as I did, if you're making more than a couple
of these. But watch out -- the metal filings like to jam up your jig and
will throw off the holes if you're not careful to keep them out of the
way. If you have to hand-drill these, start with a scratch awl to center
the hole and work carefully.
we move over to the bench vise to bend the L's into their final shape. On
my lights, the L is not symmetrical -- I made a cardboard template that allowed
me to make the bottom of the L centered under the light, when it's
installed. The measurements worked out to be roughly 2-3/8" on the
one side and 1-5/8" on the other. Precision isn't critical, but you
might want to try one out for size before doing all of 'em. Once I had the
first one bent properly, I used it to line up each additional one in the vise,
then I could just bend them over.
you just need to attach the L's to your light fixtures. That's what the
second nut was for, above. Crank them tight enough so they won't move
around, and then dab on some Loctite to keep them from coming loose as you
adjust them. Alternatively you could use a lock nut, but they're more
Somehow I got on a roll and forgot to take pictures of the next steps, so you'll have to picture them in your mind as I describe them. You can also refer to the finished pictures, above.
Once you have all your fixtures assembled as per the above, you'll want to test them. First of all, you probably forgot which color each fixture is. Secondly, if the thing doesn't work, you'll want to know now, before you get it wired up any further. I used a piece of colored electrical tape on the top of each fixture to indicate its color.
Next you'll need to hook on the base to the upper part of the enclosure. If you're feeling lucky, you could glue it. I wanted the ability to be able to get inside and work on these (e.g. if a bulb failed or wiggled out of its socket) so I simply used packing tape to hold the bottom to the top. This should be weatherproof enough, as long as they get inspected every year that the tape holds up.
Now you'll need some angle stock. Again, I used aluminum, purchased at Home Depot. Each RGB fixture set will require 1 foot of aluminum angle stock. I cut it with the hacksaw, then brought it to the drill press, where I drilled 1/4" holes on one side of the angle. One hole is centered, the other two go 2" in from either side. On the other side of the angle, I drilled 5 5/16" holes. Four of these will be used for mounting the fixture, and you can position them as you see fit. The fifth hole gets centered, and will be used to hold a wire-tie supporting our wiring harness.
Next, use 1/4" hex bolts and nuts to assemble one Red, Green, and Blue fixture to your angle stock. As above, use Loctite to keep it all snug.
Now it's time for the wiring. I used 6-conductor phone cable, which seems well-suited for this application. First of all you have a pair for each light. Secondly, it's color coded pretty nicely: One pair is Blue/White-with-blue-stripe, One is Green/White-with-green-stripe, and one is Orange/White-with-orange-stripe. It doesn't take too much of a stretch to see that you can use the Orange pair for Red, and the others for their correct color.
Polarity doesn't matter for these LED's, but for consistency, I connected the solid-color wire to the resistor bump, and the white/stripe wire to the other lead. These were soldered and covered with shrinkable tubing. I then used a couple of wire ties to neaten everything up, including one through the center hole mentioned above, for use as a strain relief.
The other end of the wire goes to your connector. Originally, I chose to use DB-9 connectors purchased from All Electronics. These are the same connectors that used to be commonly used for serial devices on PC's, and, if you're really old, Atari joysticks from the 80's. The advantage to these connectors is that they're cheap. The disadvantage is they're a bit of a PITA to work with. But, as usual, cheap trumps it out, so that's what I used. In 2009, I purchased some new LED lights that used an RJ-45 (Ethernet-style) connector. Due to the pains working with the DB-9's, creating new cables, downtime if one got damaged, etc, I decided to convert these lights to RJ-45 as well, so everything matched. Thankfully, relatively cheap RJ-45 jacks and plugs can be found on eBay.
The male connectors will go on the lights, and the female on the controller. I made up some "extension cords" to the proper length as well.
Here's the pinouts I used for the DB-9 connectors I originally used. I obviously only needed 6 of the 9 pins. You can choose any pinout you like, as long as you know what it is and stick with it. It may be obvious, but when you're soldering on the back of the DB-9 connectors, you actually want to refer to the diagram for the OTHER gender: e.g. you're soldering a female connector from the back, the wires go in as if it's a male connector.
a pic I snapped of setting up one of these connectors. In this picture,
I've soldered on the three solid wires but the striped ones have yet to be
worked on. These DB-9 connectors have a little "scoop" for each
wire. Unfortunately, it doesn't actually hold the wire to help you solder
-- you have to sort of set the wire in it, hope it doesn't spring out, then hit
it with some solder to hold it in place forever. If you heat the pins too
long, you'll melt the connector and ruin it. I found that the males are
more sensitive to this ,and you can help prevent it by plugging in a spare
female connector to use as a heat-sink while you're soldering. Also use a
clean soldering tip, as dirty ones won't pass heat properly and you'll ruin a
connector. Don't ask me how I know this. Please do note that this
picture is of a female connector that I was soldering up for the
controller side of things, but other than the pinouts, the soldering process is
I had the connections soldered, and tested it with a multimeter, I injected the
whole thing with hot glue. This should help protect the connections, keep
them from shorting out, etc. I'm sure someone reading this who's done
these connections before will cringe at this, but hey, it seems to work.
The connectors are cheap enough so that if one ever needs repair, you can snip
it off and solder on a new one without worrying about cost. Buy some extra
when you order them since shipping can be significant when you're buying 30-cent
connectors... Once this is all done, you use a DB-9 plastic hood to
protect the whole thing, as shown in the pictures above and below. The
RJ-45 connectors work essentially the same way, except they have the advantage
of being able to be installed with a punch-down tool instead of soldering.
It's much much simpler.
Above is a couple more views of the finished RGB light bank. Each light can be independently adjusted up/down and left-right. The bottom bracket can be mounted on a post, back of a display element, etc. The whole bank will easily plug into the controller channel.
Now that we know how the light-banks are constructed, we need something to control them. There's a whole other page dealing with that, so click here and come along!