Physics Game

Physics games are great fun. We play them in our backyards and on our mobile devices. They often involve any number of balls of various sizes and some virtual games use enraged avians.

I decided to make my own physics game. All I needed was a platform, since the world I live in comes with its own physics. I decided to create a modular system that would allow variety and could be approached from many different ways.

WARNING: This project includes the use of power tools. Do not use them if you are not an adult. If you use them be careful. A saw cannot tell the difference between wood and your flesh. It will cut both with the same speed and power. WARNING

Materials
2ft x 2ft x 1/4 in Birch wood
1in x 2in x 6ft wood
Glue
Finishing Nails
Glue Dots

Tools
Drill
Pegs - I used magnets scavenged from a mechanix set, but I think anything, dowels, screws, or carved stones, would work here.
Miter Saw
Jigsaw
Table Saw
¼ in. Drill bit
1/16 in. drill bit
Rotary Tool
Ruler
Adjustable Square
Pencil
Yardstick

You need to map out where the holes will be placed for the pegs. I wanted the holes one inch apart. The board is 24 inches across. I  had to account for the quarter inch along the edge for the border. So that leaves me with 23.5 inches. Then I wanted there to be some room along the edge next to the border. I started the holes at least half an inch from the border. This gave me about 22 inches to work with.

I used a square and ruler to measure each line. I have an adjustable square and I would measure to where I wanted the line. I would slide the square along the edge of the board to make my line. See the pictures for this to make more sense.

Be sure to make multiple measurements before making your line, and even after making it be sure to check it. There is a carpenter’s rule: measure twice, cut once. Follow it. If the line is off at any point just erase it and begin again.

This is the most difficult and time consuming part, but if you do not take your time the board will not work. Once you have 22 lines horizontally you will need to make 22 lines vertically. This will create a grid. You will drill your holes where the lines cross.  

Make sure that the pegs you are using and the drill bit are the same size. Too small and the peg will not fit. Too large and the peg will slide out. Test it on some scrap wood.

Now you will need to drill some guide holes. Take your smallest bit, the larger ones tend to skip about and this ruins all that time you spent making this nice grid. Using the smaller bit drill a hole at every point where the grid lines intersect. Then using the larger bit drill them out slowly. If you go too fast the wood will splinter and mess up your board surface. To keep the back of the board from splintering lay it on a piece of wood that you do not mind drilling holes into. If you do not have that you will just have to live with the splintering on the back of the board. 

You will drill 284 holes. Take a break or fatigue will make you slip much as I did once or twice.

Now you need to smooth out the surface of the board. Drilling the holes probably left some rough spot around the holes. Use 60 grit sandpaper to clear away the rougher spot and 150 grit to smooth it all out. After that use a rotary tool to smooth out the surface of the holes. This should make it easier to slide the pegs into the holes. I used a stone cone bit, there might be a more technical name. Also test the pegs with your holes and if the fit is too tight use the rotary to widen the hole a little. 

You will need a table saw and a miter saw for this next part. I used my father-in-law’s table saw. You will need the 1x2x6 planks. The border will slide onto the board. You will need to cut the pieces at a 45 degree angle. I cut the pieces to 23.5 inches at the longest tip. I marked 23.5 along what would be the outside of the border and lined the miter saw up to cut at a 45 degree angle there.

Then using a table saw I cut a 1/4 inch wide notch 1/4 an inch into the inside of each border so the border would slide onto the board. The notch was 1/2 from the bottom of the border. You will need to make multiple passed to get the right width and be sure to use a test piece so you don't mess up one of your good pieces.

Once all the pieces are cut you can slide them into position on board. Place a little glue on the corners. I also put a finishing nail into each corner to hold them in place. I used a finishing nail in my drill to prime the hole so I did not split the wood.

I made several different pieces here. I split the wood left over from the borders in half. For each piece I would lay it on the board and mark where the magnets would go. I used glue dot to hold the magnets in place because they allowed me to shift the magnets position slightly when placing it on the board. While most of the holes are equal in distance there can be small variations that make a more permanent adhesive difficult. Since I did this by hand not all the holes are perfect. Then I would use the magnets from the mechanix set I have.

1.  Catcher
I cut a 2.5 inch piece of the 2x2x6 plank. Then I measured about 3/4 an inch in and cut notches out of the wood with my jigsaw. I then broke off the notches and sanded it smooth. Then I measured a shim off and cut it to go on the outside of the catcher. Once it was cut I nailed the shim to the outside of the catcher with four finishing nails.

2. Long Angle Platform
Using a ruler I measured off about 9 inches from a piece of the 2x2x6 plank.

3. Short Angle Platform
Using a ruler I measured off about 3 inches from a piece of the 2x2x6 plank.

4. Long Horizontal Platform
Using a ruler I measured off about 5.5 inches from a piece of the 2x2x6 plank.

5. Short Horizontal Platform
Using a ruler I measured off about 2.5 inches from a piece of the 2x2x6 plank.

6. Adjustable Platform
Using a ruler I measured off about 2.5 inches from a piece of the 2x2x6 plank.  Then I drilled a hole in the middle using the 1/4th inch bit. I took a roofing nail and cut off the sharp end so that only 1/16th protruded from the hole of the platform. The magnet is attached to the end of the nail.

7. Rubber Band Platform
Using a ruler I measured off about two pieces half an inch each from a piece of the 2x2x6 plank.

8. Swoop Platform
I used a bowl to measure out a curve on a piece of the 2x2x6. Then I used my jigsaw to cut out the curve. Then I used the miter saw to cut off the ends.

The board needs to be at a slight angle for gravity to do its part. Using a stack of books I determined the angle at which the marble would rest in a hole, but still roll over the holes when started. The angle was about 12.5 degrees. This meant that my legs would be 5.5 inches. I measured and cut them.

I put two legs at the top. I laid them in the closed position and using a finishing nail as a bit drilled through the border and into the leg. You may have to remove the head of the nail if you do this. Then sand down the leg so that it rotates out from the resting position.

If I did the legs again I would use hinges instead of nails.

This game can be played many ways. You set a start and end point for the marble. Then players have to come up with a solution that will deliver the marble to the endpoint.

<iframe width="640" height="390" src="http://www.youtube.com/embed/D4lsfCAgjGI?rel=0" frameborder="0" allowfullscreen></iframe>

From there you can add rules or limitations. You can see who can get the marble in with the fewest pieces, with the most pieces, in the shortest amount of time, or using only a limited number of pieces. You could spend all day coming up with different games.

If I win the makerbot challenge I plan to use it to fabricate more platforms for my game or even use it to make a modified version of this game.