A vibrating "robot" bug that hums like an insect and walks around on its own. Easy construction with a lot of opportunities for kids to learn. The bug works very well on tiled floors, where it follows the grid as a foot gets stuck in a groove. Depending on how it is balanced, it will move around a room and provides lots of fun for youngsters. I used the cheap syringe switch Instructable for a battery pack and on/off switch.
Step 1: Materials
The bug is made from materials that are available around the house. There are many different vibrating toys and this is certainly one of the easy ones to build. You may of course improvise and use anything that is available. The soda can must be empty, but can also be substituted with a cardboard roll, a plastic bottle or whatever you desire, as long as it is not too heavy and has air inside to help create the BUZZZ effect. The little electric motor is from an old toy, but can also be bought for around $2 US from electronics supply stores. Here is the list:
1 empty soda can
2 x 5 inch cable ties
1 x 20 inch cable tie
a good length of wire (see picture)
1.5V toy motor
small gear or connector that fits motor
small bolt and 2 nuts
thin electric wire
soda bottle top
1 AAA battery
a small syringe to hold the battery
2 more nuts, to make the switch
Step 2: Tools
Nothing fancy here.
Step 3: Assemble feet
Bend a length of wire around the can as shown. Repeat so that you have 2 of these.
Step 4: Assemble wings
Bend two "wings", making sure that they are mirror images. I used a different color wire than the wire I used for the feet here. You can also make more realistic wings from a sheet of transparent plastic, or use painted cardboard.
Step 5: Glue and solder
Attach the gear to the motor and glue the bolt with 2 nuts on the gear. This makes the motor vibrate as it is off-centre. The vibration makes the air inside the can vibrate as it spins and provides a humming noise. Solder a length of wire to each of the connections of the motor. Make sure that the wire is long enough to reach around the can to be connected to the battery holder and switch.Instructions to make the syringe battery holder and switch may be found at this link:http://www.instructables.com/id/Cheap-Battery-holder-and-switch/
Step 6: Assemble the Bug
Attach the legs and wings using tape to secure them to the can. Tape the motor assembly to the belly of the bug and the battery holder to the top using tape to secure them in place and tie them down with the longer cable tie. Insert the soda cap between the can (body) and motor assembly to allow free movement of the motor and its load (see previous step images). Use the two short cable ties as antennae for the bug. This is just a cosmetic feature, as is painting the can before assembling the bug. I took some pictures of one I painted black, to which I wanted to add yellow stripes to make it look like a bee. Unfortunately, my 8y old student decided not to have the bug look like a bee (he reported that it cannot be a bee because it only has 4 legs).