Start with 3 inch wide (1/2 inch high walls) aluminum channel, 29 inches long.
Print the seesaw al bracket and attach it to the center of the aluminum channel with machine screws.
Add the seesaw cap to one end of the channel.
Add acrylic shields to the end and right side of the channel (these are to keep Froggy from bouncing out). I screwed one piece of acrylic on and I "welded" the other by "painting" (small brush) acetone on the abs printed part--then holding the acrylic against the abs printed part.
Using the balance base a, catapult motor c and catapult motor lid (printed 3d parts), attach the servo motor to "the tower."
Attach a 1 1/2 inch diameter, 7 1/2 inch long acrylic rod to an 8 inch by 6 inch by 1/2 inch (painted plywood) base.
Find a position "midway" in the servo travel and let the motor rest there. This way, when you attach the channel in a "mid travel" position; you'll know that you have room to make it move by software where it needs to go.
Pre drill holes in the top of the acrylic rod to accept the gear bearing holder.
Mount the servo horn to the seesaw al bracket, then mount the channel to the servo motor. Fasten the servo screw in the center.
The wood dowell (1/4 inch diameter) should fit into the bearing and slide through both holes in the seesaw al bracket.
It should look like this.
Fasten the gear bearing holder to the acrylic rod with a machine screw to fit your pre-drilled hole.
Take a 5 inch long (1 1/2 inch diameter) acrylic rod and saw one end to an angle that is similar to the angle of the aluminum channel when the channel approaches the train. Secure this acrylic in a block of wood (I drilled a 1 1/2 inch hole and friction fit).
Glue (superglue) a piece of sponge to the acrylic rod, then fasten the assembly to the base with screws.
Print the seesaw support and glue sponge into the cradle at the top. Attach this to the base.
Wire according to this schematic.
Enter this code in the Arduino:
int start = 10;
int next = 7;
int val = 0;
void setup ()
void loop ()
Adjust the "myServo.write" numbers to keep the movement "soft" and to reach the appropriate end positions.
To avoid litigation from "adventurous plastic attorneys," I built a caution sign--indicating what will happen if a frog sits on the end stop cradle.
Connect it to the last ride (The Boot) and let the fun begin!