Drilling the Coroplast
Now that you know what we are building let’s start by laying out the drilling pattern for the 4′ x 8′ sheets of coroplast. With the coroplast sitting vertically (4′ from side to side and 8′ top to bottom), there will be 18 holes across (horizontally) and 38 holes up and down (vertically). This is a total of 684 holes.
Each hole is a 12mm hole in size which is just large enough to pop a bullet pixel into each hole. They will snap in and stay there really well. After they pop into place, they will be a bit harder for them to come out.
Here are the rules I followed when laying out the board.
1.Holes on the left and right side columns are 1.3 inches from the edge of the coroplast to the center of the holes.
2.Holes on the top are 1.3 inches from the top of the coroplast to the center of the top row of holes.
3.Holes are all 2.68 inches apart from each other (center of hole measurement).
4.Holes are all 2.53 inches apart from each other (center of hole measurement).
5.Holes at the bottom doesn’t matter as long as they are on the board.
You may be asking if the difference between the spacing of the vertical vs horizontal causes issues with a circle looking like an oval instead of a circle. The answer is the difference is not a big difference and your circles will still look the same. I originally had concerns also and everything I display looks great. Circle are circles.
Use a 2″ x 12″ board for a drilling jig.
The 2×12 must be cut to exactly 48″ long (the width of the coroplast). A PDF of the drilling template can be downloaded here. What I did was print out the top 5 or 6 rows on a 4 foot piece of paper but everyone cannot do that.
(You can measure the holes based on the measurements I gave above and mark them on the 2×12)
We took the paper template and laid it over a 4 foot wide section of a 2″ x 12″ piece of board. We marked through the paper with a sharpy pen to mark the center of the holes.
Once the holes were marked, we drilled holes in the 2″ x 12″ with a 12mm drill bit. You must make sure the holes are accurately placed. You will save yourself a lot of pain later by making sure this initial step is accurate. Make sure you do not tilt the drill when drilling the holes (use drill press stand mentioned in Part 1 if possible). Make sure all holes are drilled exactly where they need to be.
Once you have the holes drilled in the 2×12 and are satisfied they are accurate, we are ready to start drilling the coroplast. We used 4 saw horses and a thick piece of 4’x8′ sheet of plywood for the next step. Lay the 16 sheets of coroplast on the plywood on top of the saw horses making sure they don’t droop. Stack all 16 sheets perfectly together then clamp them on multiple places. The more clamps you use, the better off you will be. You do not want any sheets to move.
Once everything is clamped down good and tight (but not too tight, don’t smash your coroplast), your ready to start drilling the coroplast. Place your 2×12 “jig” over the stack of coroplast and line it up the top and side edges. Once lined up, clamp it down.
If you have the drill stand, you will want to use it to drill the holes. DO NOT TILT YOUR DRILL AT ALL OR YOUR HOLES ON THE BOTTOM PANEL WILL BE WAY OFF! The drill must remain perfectly vertical. A small makes a big difference the further down in the stack you go. Just be very attentive to what you are doing when drilling.
Dill all of the holes in the jig down into the coroplast with a 12mm drill bit. If you have to move a clamp, then move it when needed. Once you have drilled all of the holes in the fixture, take a screw driver and poke it into every hole to make sure you got all of the holes. It is easy to miss one and you want to do this step before you move the jib to the next position.
If all holes have been drilled with the jig, it’s time to move the jig down. Unclamp it and move it down making sure the top holes of the jig are over the last row you had drilled. Place a couple 12mm drill bits into the top holes of the jig so they stick down into the last row of holes drilled. Once you have the jig aligned to the last row, it should already be aligned to the edges of the coroplast. Make sure it is. Once it is in position… clmap it down and drill the holes.
Keep repeating this procedure until you have made it all the way to the bottom of your coroplast. Once you drill the last row, you have just drilled 10,944 holes. Give yourself a pat on the back. Take a break.
Now that your coroplast is setup to receive the LEDs, we will begin to load the LEDs into the coroplast. This is a long tedious process but the rewards are great.