Introduction: Jumping Halloween Spider

About: The RobotGeek team is a 6-man operation that wants to make it even easier to use Arduino to make electronics and robots. Check out our instructables and for all of our awesome kits.

Halloween is approaching rapidly, and what's more fun during this spooky holiday than scaring friends and family? This spider will hang from any structure in eerie silence until it detects motion, then it will strike!

This is a simple project using a PIR motion sensor and a servo that can be completed in just a few hours. Try it out and see who you can spook!

Step 1: Parts List

Step 2: Making the Spider

Designing this spider was super simple and took less than an hour.

We started with an oval shape with a line down the center so we could use the revolve tool on one half of the oval to fill it out. Next, we used the sphere tool to make the head of the spider, making sure that it overlapped with the body. Then we added a post on the spider's back for the spring to attach. We made a hole through the post for a 2m screw to be inserted to hold the spring in place. Finally, we cut off a rectangular area under the spider and used the fillet tool to round the edges.

Step 3: Making the Horn Attachment

We made the horn attachment the same size as the horn we are using in this project, and added slots for screws. Again, a post was added for spring attachment.

Step 4: Modifying the Servo Holder

We added some ledges to the servo holder for our gear ties to sit, making it easy to attach the servo to most structures.

Step 5: Wiring

As you can see, the wiring is very simple. The servo attaches to pin 11 while the PIR sensor attaches to digital pin 12. We taped a small tube around the PIR sensor to limit the sensing range. This is not required, but does make it so the spider will jump only when you are next to it.

Step 6: Spider Assembly

Cut eight legs from the pipe cleaners, place in the body holes, and bend into leg shapes. Next, attach the spring to the post on the spider, using a screw or bolt to keep the spring in place. Repeat this step with the post on the horn attachment. Place your gear tie around the servo and twist the ends to secure.

Step 7: Code