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