The 2009 LED Tri Star Project
Using Coroplast Material
This project is going to provide a couple of benefits. First, these ropelight tri stars have been used in our display for 3 years and are
starting to fade a bit. In addition, because of their incandescent ropelight construction, they use a lot of energy. And, finally, the color scheme needs to be
updated just a bit as well.
The goal of this project is to replace these decorations with a homemade design consisting of LED lights, and change out the yellow lights for blue.
The final product will have red, green and blue LED lights to match the display color scheme. The challenge of the design will be to calculate the best size
of the concentric stars so there are a minimum of leftover or unused lights from the LED strings.
That will be tricky because of the three different-sized stars used in the
decoration. It would be pretty easy to design one star or two stars to use all the lights, but to get all three stars to match up with light string lengths will be a challenge.
Three stars, three strings of LED lights, less energy, and minimizing leftovers - that's our goal.
This project is complete from a construction process, we're just waiting for the lights to arrive so they can be installed...Here's what we have so far:
We start out by doing a search to find some pre-drawn 5-point stars that we can use to trace a good pattern. Using our laptop and our trusty
projector, we find a suitable star pattern that looks nice and symmetrical. We'll capture this picture file and then paste it into our favorite photo software package
(IrfanView) to work with it further.
Now it's time for some star geometry calculations. Remember in school when you asked if you'd ever use that math stuff? Well, this is one of those times...Ha! We need
to figure out some basic geometry for the star.
First, for the design, we'd like lights to be located at each point where two lines come together (at the starting
and ending points for each segment). That works out to be 10 lights, no matter how large or small the star turns out to be. Then we have to figure out how many lights
will be placed on each segment in between the segment "starters" and "enders" as discussed. That will determine the total number of lights used in each star...
We start with the task of sizing the inner star first. Our method is to tape up some white butcher paper on a door in the garage and
project the images on it for use as a pattern to build the decoration with Coroplast. As a first guess, we size this first star with the projector zoom to have 3"
segments. That makes the star 8" from left tip to right tip (3" segment + 2" gap + 3" segment).
I realize by doing some rough calculations that this size of star
will allow LED lights to be placed every 1". Let try that out and see what that gives us. To figure out the total number of lights that will be used, we come up
with an equation (there's that math stuff!):
2 lights on each segment plus the corners = 10 + (10 * 2) =
30 lights total for the star
3 lights on each segment plus the corners = 10 + (10 * 3) =
40 lights total for the star
4 lights on each segment plus the corners = 10 + (10 * 4) =
50 lights total for the star
5 lights on each segment plus the corners = 10 + (10 * 5) =
60 lights total for the star
6 lights on each segment plus the corners = 10 + (10 * 6) =
70 lights total for the star
Since light strings come in 35, 50, and 70, we'll use those sizes for the stars. For the smallest star size, we'll have to use the initial design to set it up for
30 lights and then insert 5 more lights into the center of the star to get it up to 35 lights (see photos below).
It makes sense (from the above calculations) to make the small star 30+5=35 lights, the medium star 50 lights, and the larger star 70 lights.
Let's project the second star (with 4 lights on each segment in between the start/stop points) and see what that looks like. Looking good so far...We want the stars
to stack on top of each other and look symmetrical.
Here's what the pattern looks like when projecting the image on the paper for the third (and larger) star. It looks nice and symmetrical,
and the design is almost there. Piece of cake!
After tracing the stars on the butcher paper, we take it down from the door and lat it on a flat surface to patch it up with a straight-edge and
make any necessary adjustments with our trusty eraser. Then we're ready to tape it onto a piece of coro and mark it for hole punching.
Starting the process for marking the pattern for holes to be punched. The lights will be 1" apart from each other, and the small star
will have 5 additional lights in the center to boost the light count to 35. I think this will work!
Here's some of the design notes and calculations for the light counts for the various configurations of the star patterns. The LED
light strings are on order, and should be here shortly. Then we can finish this project and build two of these stars.
Here's a photo of one Coro Tri Star after the holes have been been laid out and punched with a scratch awl. They're ready
for lights to be inserted. This design was carefully chosen to use light strings that have 35, 50, and 70 LEDs for the different stars. This way no left over
lights have to be tied off or covered up on the rear of the Coro piece. We've also constructed wooden frames for these two Tri Stars; see photo below...
Here's an almost finished Coro Tri-Star in its frame. The lights are installed, the coro is enclosed in the frames, and they're
almost ready to go. We just need to do some more touch-up paint on the outside of the frames. The Christmas Lighting season is almost here; be sure to stop by
Belardo Lights and see them!! These babies are going to be BRIGHT!