I got my idea from evil mad scientist laboratories. They used LEGO to power there pumpkin but I found some cheap gears and axles from the k'nex company. Over all the build was a success!
Step 1: Materials
2 yellow rods (k'nex)
2 red rods (K'nex)
2 k'nex wheels (pully and tyre)
2 green rods (k'nex)
1 grey rod (k'nex)
K'nex small cog
K'nex large cog
3 crocadile clips
battery pack (for 4 AA batterys)
Black ball Joint
Step 2: Cut the Pumpkin
Note: I have cut the top of and not used it because we won't need it for this Instructable.
Step 3: Motor
Next stick it down and hold it in place with duck tape.
Step 4: Motor
Step 5: Motor Axel
Thred the red rod through the motor and stick a black ball joint on the end.
Step 6: Gears
First connect the two green rods to the black rod connectors like shown in the picture. Then connect the yellow/grey rod connectors to the green rods like shown in the picture.
Finally slide the small gear cog on to the red rod you put there in step 5
Step 7: Wheel Axel
First slide the red rod through the grey/yellow rod connector's hole in the middle of it like shown on the picture. Next clip the black ball Joint on the end
Step 8: Large Cog
First clip the wheel on and slide the large cog though the rod on to it so it clips in
Step 9: Wheel 1
First clip the tan clip on next to the large cog and then slide the wheel on to it.
Step 10: Axel Surport 1
First slide a white/black rod connector on the the red axel with the small cog on. Next attach a green rod and a yellow/grey rod connector to it like picture two.
Finally put a black ball clip on the top axel (one with wheels) and punch a hole in the plastic so a green rod can go through it like shown in the picture.
Step 11: Wheel 2
First clip the tan clip to the wheel axel (again!) and then slide the wheel on to it (also again!)
Finally clip the black ball joint on the end.
Step 12: Axel Surport 2
First clip the white/black rod connector to the yellow/gray rod connector (which you used in step 10)
Then again punch a hole in the correx and put a green rod in like shown in the picture
Step 13: Finished Gears
Step 14: Cutting the Pumpkin for the Motor Space
Firstly lay your correx down on the pumpkin and trace around it (lay your correx so the wheel face away from the pumpkin, so when you install it the touch the ground and the motor switch faces down)
Note:you may need to cut the correx back to fit on your pumkin
Note: When you cut the bottom of your pumpkin out get lots of the inside out as well to save wieght.
Renember, this is on the bottom of you pumpkin!
Step 15: Installtion of the Motor Part 1
With your correx being underneath you wheels/cogs clip the yellow rod in like shown
Next with a grey rod stick it through one side of the pumpkin and through the middle (going just above the correx like in picture 4) and out the other side.
Step 16: Installtion of the Motor Part 2
With your other yellow rod stick it through the hole marked in picture two and then through the pumpkin and out the hole in the other side.
Finally you red rod poke it through the pumpkin just above the motor like shown in picture five.
Step 17: Wheel Three (The End of the Motors and Gears)
First clip the white/black rod connector to the red rod you put there in step 16. Next put a whit rod through the hole and in to the pumpkin like shown in picture 2 and three. Repeat the same on the other side.
next slide a wheel on to the yellow rod and clip two tan clips on either side like shown on picture 5.
Note: You may need to reduce the weight on the pumpkin by cutting chunks of pumpkin out with an extremely sharp knife (picture 6)
Step 18: Drying
Step 19: Electronics
For this step you will need a battery pack for 2 AA batterys, and a crocadile clip.
First glue your battery pack in place and hold it down with duck tape on to some correx. Next clip a crocadile clip on to the battery pack and hold it in place with duck tape.
Step 20: Electronics
Now Clip your crocadile clip to a toggle switch. Next clip another crocadile clip to the toggle switch.
Note: Leave the toggle switch off.
Step 21: Electronics
First clip the crocadile clip which you just clipped on to the toggle switch to one of the LED's.
Next put some solder of the tip of you soldering iron and then place the iron and solder next to the bit you want to solder (LED to Electrical wire) and melt the solder on to the wire and LED with the iron.
Note: Solder the Other LED to the wire as well.
Step 22: Electronics
All you need to do is clip the crocadile clip to the LED you havn't cliped one to and then clip the other end of the crodile clip to the battery pack
Now place you circuit in to your pumpkin and make holes for the 2 LED's to act as eyes. You could also create a mouth, but I would do that before you put the circuit in. Make a hole in the side of th pumpkin for the toggle switch
Step 23: You Finished
Now go try you ROBO-PUMPKIN, if you have any probalems with, do contact me through comments or you could personal messege me.