Outdoor String-of-Lights Tree for the Holidays.

This was our first year doing some DIY holiday lights that were synchronized to music, so we started small, just adding a feature or two to our existing static light display.

I made a tree out of a 10 foot 1/2 inch EMT conduit tube, coat hangers, and 16 strings of 50 count mini lights.

This instructable is about how to build the 10 foot tree, quickly and cheaply, for the techniques of sequencing the lights to music, there are other instructables and also the nice folks at www.doityourselfchristmas.com

Videos of the final result are on vimeo here:

Holiday Light Show 2011: Deck the Halls from Neil Hendin on Vimeo.

http://vimeo.com/user9920085/holiday-light-show-2011-deck-the-halls

And for a different song:

Holiday Light Show 2011: Wizards In Winter from Neil Hendin on Vimeo.

http://vimeo.com/user9920085/holiday-light-show-2011-wizards-in-winter

Step 1: What You Need

To build this tree you will need:

Parts:

16 strings of 50 count mini lights. I used incandescent, since they were cheap at about $2.50 a string. Source: Lowes
1 10 foot length of 1/2 inch EMT (electrical conduit), about $2.00. Source: Lowes or any home center.
1 1/2 inch conduit junction, to join 2 pieces of the 1/2 inch EMT tubing. $0.98, from Lowes or where you get the conduit
1 3 foot length of 5/8 inch diameter rebar, $1.78.
16-18 metal coat hangers, more if you mess up a couple,
1 pack of epoxy plumbers putty (optional) $5.00 from any hardware store.
32 small cable ties, which I had lying around.
1 glass beer or root-beer bottle, empty. How you get it empty I won't comment on :-). (optional)

Tools:

Heavy duty wire cutters to cut coat-hanger wire. Don't use the good ones you use for electronics, or they will be damaged.
Heavy duty pliers to bend coat-hanger wire
hacksaw or tubing cutter to cut the EMT conduit
small clipper for clipping the cable ties off, and perhaps a small pliers to tighten them
screwdriver that fits the set screws on the emt conduit junction, a #2 philips is common for this.

Step 2: Prep the Coat-hangers

Take 8 coat hangers, and cut them on the 4 cut lines shown in the photo.

Save the hook part, it makes a great steak to hold down the light strings later on.

In looking over it now, you could combine the 2 cuts on the straight, long portion into one cut, the resulting U shaped pieces will be asymetrical, but that won't be a problem.

Bend the 2 U shaped pieces as tight together as possible, as shown in the second photo.

Step 3: Prep Conduit

Cut off about 10-12 inches of the conduit, to allow easier working with the end part so it's not so unwieldy. It will be joined back up with the longer piece via the EMT junction later.

Insert all 16 bent coat hanger pieces into the end of the conduit. They should fit snugly.

Leave about 2.5-3 inches hanging out one end.

Step 4: Bend Coat-hangers

Start by bending each coat hanger end down at an angle as shown. Try to maintain about the same length for each one, but it is not critical.

The ones in the center wll wind up slightly shorter as they have farther to bend.

Also keep an eye out for how to arrange them in roughly 16 equal spaced sections. Imagine they are numbered 1 through 16, and you therefore have 180 degrees between 1 and 8, then 90 degrees between 1 and 4 and so on. It's fine to eyeball it.

Then bend the end of each of the coathangers up, to form a hook. again adjust for angle as needed, but it's not super critical.

to hold the piece upright while adjusting, i found that an empty bottle works well.

Step 5: Epoxy It Together

If your coat hangers are a very tight fit you might well be able to skip this step, or you could jam a couple more pieces in to make them really snug (perhaps those pieces could hold up a tree topper)

To ensure that things stayed were I put them, I took about half a stick of plumbers putty (an epoxy putty that you knead together and it hardens, it comes packed like a roll of grey clay with a black center, knead it till the color is uniform, you will want some disposable gloves on for this I suspect.

The beer bottle works well to hold it as you form up the putty,

Let harden according to instructions on the package, typically a few hours to overnight.

Step 6: Plant the Tree & Prep the Lights

Find a location for your tree, with at least 10 feet of vertical space, preferably much more, at at least 4-5 feet in diameter.

Take a hammer and bang the rebar piece into the ground about 1 foot, so about 2 feet are left above ground. Adjust depending on your soil.

slide the longer (about 9 foot depending on how much was trimmed off earlier) piece of EMT over the rebar. It should fit nicely.

Get a ladder and join the smaller piece with the coat hangers on top of the longer piece, and screw it in tightly.

Step 7: Install the Lights

Test all 16 light strings and get them un-tangled if needed.

Locate the female plug end. This is the end at the far side of the light string from where you plug it in. Put another way, it's where you would plug the _next_ strand of lights into should you be daisy chaining them.

Take a cable tie and bend the female plug back onto the cable and tighten the cable tie, you should have a small loop in the end of the light string which will hook on to the coat hangers.

Clip off the excess tail of the cable tie.

Repeat this on all 16 light strings.

Climb the ladder and hook each string on a hook, try to keep them un-tangled as possible from each other, but we can fix it later if necessary.

Step 8: Anchor the Lights.

Take the hook parts of the coat-hanger left over from the earlier step and bend the hook straight, you should have a Tee shape made up of the neck and "shoulders" of the coat hanger. This makes a great steak to hold the light strings down with no waste.

You may need 3 or 4 more coat hangers to cut up and make steaks out of all the bits of them as well, as we should only have 8 of the hook parts left over from earlier, and we need 16 total.

Using a tape measure, measure out the desired radius from the center pole. The exact distance you can use depends on your light strings and the desired tree angle. I used 4 foot diameter, which is a 2 foot radius. Place a steak 2 feet from the pole. Anchor a strand to that steak, tie it off with a cable tie.

Note: you will want the strands to be slightly snug so you may wind up with some extra length on the ground, and not have all 50 lights up each strand. This extra length can be helpful in reaching an outlet box near the center of the tree. If the excess lights on the ground bother you, you can cover them with black heat shrink tubing or electrical tape.

Count over 8 strands and measure 2 feet out from the pole, at a 180 degree angle from the first steak. A quick way to do this is to set the tape measure to 4 feet and line it up with the first steak and the pole. If this makes sense, please thank your geometry teacher.

Pick a location purpendicular to the first 2 steaks and then anchor the next one, find a strand between the first two and tie that one off. Repeat on the other side.

You should now have 4 strands forming a nice tree shape at 90 degrees to each other. Continue around the base as you see fit, keeping the strands un-tangled and the spacing even. I did the next 4 strands at 45 degrees to the first set, then 135, and so on, so I kept adding strands of lights between existing ones, as it's easier to eyeball that way.