During this step, we will finish the frame back plate as well as the front of the frame.
First, mark with a pen center of the holes that you made in your design on top of A4 plywood and later on the A4 PET transparency sheet. You can do this by using the already glued frame and placing it on top of them.
When they are marked make small holes with your hand drill for reference, I suggest you do it both at the same time, you can achieve this by dropping both sheets together so it helps you make the holes as adapted as possible.
The next step is to drill the holes, In my pictures I use a drill press. but you can archive the same result with a hand drill with a big head and then grind it in the hole until you reach the desired diameter. It will be easier with a drill press, so take your time otherwise, this is an important part of the game really works!
When the holes are drilled, check with your board to see if they are aligned, you are ready to attach the pieces of the maze to the back plate. Remember that this is not the back of the frame but just a back plate for the labyrinth.
The last steps are to create a slope for the ball to roll, support for the maze and a small exit for the ball to be retrieved. To make the slope cut a piece of the will in a triangular shape. take into account that it should not block any hole.
When the slope is finished, we are ready to stick it in the back of the frame. The back of the frame consists of a piece of plywood that should be the size of the frame up to the edges that you can attach to the main frame with small nails and a hammer. We glue in the support in the corner of the frame and the slope in the bottom without blocking any holes and rear outlet holes.
You can screw in the support with 2 screws on each side of the upper lip. Remember to have the support centered, use a little tape as a guide to each side and center the piece.