Construct the drive wheel
To make the big wheel, cut the tops off of two plastic cups. Slide them together, rims facing out. Tape them together. Then glue cardboard circles to each side.
ALTERNATE - other items that can be used for a drive wheel include a card board ribbon spool, styrofoam cups, section of a round oatmeal container, or other cylinder that is about 3" - 4" in diameter and at least an inch or two thick.
Cup rims taped together can form the base of your wheel. Add cardboard circles to each side to complete the wheel.
This example uses a cardboard ribbon spool with rubber bands for traction. TIP: Glue short craft sticks at center for added support.
Set up box
Make a hole in the base of the box large enough to fit your wheel. This will be the bottom of your Rover.
On your medium sized box, mark the size of your wheel.
Then cut opening for your wheel.
Make the axle
Cut slots in the side of your wheel large enough for the craft stick. Then put the craft stick through the slots and cut one end so it is has a straight edge to attach to the motor mate.
TIP: Since this is the drive wheel, add something like rubber bands for added traction.
Put craft stick through the sides of the wheel and cut one end so it is straight - keep the other side of the stick rounded.
Make an axle holder
To make an axle holder for the craft stick on your wheel, cut a strip of cardboard and fold it like a tent (see photo). Make a hole in one side of the tent that is the size of the tip of the craft stick. Tape your axel holder down next to the hole you made for the wheel in your box.
For axle mount, fold a piece of corrugated cardboard so that is stands up with tabs that can be glued or taped in place.
Cut a hole the size of your craft stick - but only on ONE side of the axle mount so the stick won't poke through. Tape or glue axle mount next to the hole for the wheel.
Attach your wheel
Mount the motor on the other side of the wheel opening - across from the axle holder. Set the wheel in place with one side of craft stick attaching to the motorMate and DC motor. The other end of the craft stick sets in the hole of the the axle holder. You may have to cut the craft stick to fit.
Mount the motor in your box - use shoes or cardboard to raise it up a little - and attach to craft stick with MotorMate.
Attach the other end of the craft stick in the hole of the axle mount. You may need to adjust the size of the craft stick to fit.
Build the outside wheels
Cut a paper tube into six pieces to create wheels about 1-2 inches wide. Cut six cardboard circles to fit inside the wheels. Using a skewer, poke holes in the center of each circle. Place a cardboard circle in each paper tube and glue in place.
Cut six pieces of paper tube (about 1-2 inches in width).
Cut six circles of cardboard and glue inside each of the paper tubes.
Attach the outside wheels
Make three holes in opposite sides of the box for axles. Poke skewers through a hole in one side of the box and out through the hole on the opposite side. Glue wheels on the end of the skewers. Special Note: The two middle wheels are just glued in with short axles because a longer axle would interfere with the center drive wheel. These middle wheels won't spin.
Use the skewers or chop sticks to attach the wheels to each side of the box. Note the drive wheel should be lower than the small outside wheels.
Connect your circuit
Connect wires to the motor inside the box and then connect the rest of the bits (see photo of circuit). The Power, IR, and Motor can all be inside the box. The Light Sensor and Number bits will be outside the box.
Connect the bits to form the circuit -- Power + IR Trigger + Wire + Motor + Wire + Light Sensor + Number.
Make sure that all the wires are out of the way of the center drive wheel inside the box.
Add the Rover instrument
Rovers carry scientific instruments to take measurements and send data back to Earth. This instrument is an energy sensor. It will sense the amount of light and display data on the number bit.
To add the instrument, put a craft stick or pencil vertically through the top of the cardboard box near the front. (Be sure not to get in the way of the center drive wheel inside). Stick a small box on top of the craft stick and hot glue in place. Tape the light sensor and number modules to the front of the small box. Cut a small hole in your box so you can access the power switch.
Stick a small box on top of the craft stick or pencil and hot glue in place. Tape the light sensor and number modules to the front of the small box.
Decorate your box
Get creative! Add stickers. Paint. Cover with foil for a high-tech space look. Then take your rover for a drive using any household remote control.
Decorate and control your rover using any household remote. The trigger will turn the motor on driving the center wheel. You are ready to drive on Mars!
Try different materials like the bottoms of soda cans for the wheels to create a techy-look.