PUMPKIN RACING, a creative twist from the typical pumpkin carving contest. Whether you are racing just a few pumpkins at a small Halloween party or running heats at a community event, you are sure to have a good time.
If everyone put their pumpkins on a skateboard, there would be no challenge in the race. So, to make the race a contest of intelect as well as creativity, the rules require two independent axles.
The secret to this is simple: For the PUMPKIN RACER to be fast and run a straight course, the axles have to be parallel. You have no hope of getting parallel axles if you just try poking axles through the pumpkin, and let's face it, it is a lot more fun to win than to crash into the curb.
The following instructions will show you how to make a contraption to create parallel axle holes.
You really need to see the Instructable entitled HOW TO BUILD A PUMPKIN RACER, to fully understand and appreciate the purpose of these instructions.
(1) piece of flat weld steel, 1/8 x 3 - three feet long
(1) three foot long piece of oak staircase rail 4 x 4 x 4
(1) 3 foot piece of weld steel rod, 5/16 diameter
(1) wood drill bit, 5/16
(1) metal drill bit, 5/16
Ruler or Tape Measure
Pencil or Sharpie
Step 1: MARKING DRILL HOLES ON STEEL
I should note that this is the second generation PUMPKIN AXLE PUNCH. After repeated use, the drill holes began to enlarge. That allowed for some wiggle room and the axles were no longer parallel. So, to avoid this problem, this Instructable has a plate of steel to reinforce the holes.
Also with this example, there will be more holes to accomodate a wider size range of pumpkins and wheels.
First you want to draw a grid on the steel to determine where to drill holes. Five inch rubber wheels are the starting point for this grid. The pumpkin, of course, cannot drag on the ground. A one-inch clearence under the pumpkin will allow for bumps in the road. Half the wheel size is 2.5 inches. One inch to lift the pumpkin off the ground. So, with this example, the first line of the grid is at 1.5 inches.
Then place a dot every two inches along the line you just drew for the length of the three foot steel.
Step 2: DRILLING FIRST SET OF HOLES
Now you are ready to drill a hole at each point.
We are using a 5/16 metal drill bit, standard length. The diameter of the steel rod we will use later is 5/16 and should fit quite snug into the holes when we are finished.
TIP: The drill bit can slip on the steel. If you take the punch and make small dents in the steel, it will help hold the drill bit in place.
Position the drill bit over the dent you have just created and you are ready to drill. You will be able to feel the dent as you move the bit across the steel.
When you are done drilling all the holes, you will need to give them a LIGHT sanding in and around the holes. Check to make sure that the steel rod can be inserted into each hole.
Step 3: ATTACHING STEEL TO 4 X 4 WOOD PIECE
Now that you are finished drilling the steel, you need to attach it to the oak 4 x 4. Some strong glue will help keep it in place. I like to use a water and weather proof glue. Also, I don't like to use expanding glue.
After you have the glue spread over the steel, being careful to stay away from the drill holes, you can line the edge of the steel up with the edge of the oak railing.
NOTE: The reason for the oak railing is because oak is a hard wood and the drill holes are less likely to expand over time. Also, the manufacturer has already sanded and squared the wood. It is well worth the extra few dollars it will cost compared to rough pine or cedar.
Step 4: DRILLING FINAL HOLES IN 4 X 4 WOOD PIECE
I really tried to come up with a way to do this step without a drill press, but I just could not get the holes drilled straight. Reluctantly I admit that a drill press is needed.
SAFETY TIP: You need to make sure that the steel plate is firmly attached to the 4x4 before you start drilling. I added a few wood screws just in case. You do not want the steel plate to come loose while you are drilling the final holes. This could create a hazard.
It is important that you be able to drill straight through the oak 4 x 4. You do not want to go half way, turn the wood, and try to match the hole from the other side. You also want these holes to be tight, so do not expand the hole by moving the bit up and down repeatedly.
Step 5: MAKING THE DRILL BIT FOR THE PUNCH
Measure to the center of the steel rod. Place the rod in the miter box and cut it on an angle to form a sharp tip in the steel rod. Give it a light sanding when you are finished. You have now created the punch or drill bit that will be used to create the axle path.
With the scrap piece of wood, create a handle for the rod by drilling a 5/16 hole partially through one side. Glue the wood to one piece of steel rod.
NOTE: We have tried a few different options to create the drill bit. 5/15 diameter long screwdrivers tended to bend and failed to create parallel holes after time. A long drill bit tended to expand the wood punch holes over time. The steel rod has proven to be the best option. Do take time to pick a piece that is straight. You can roll it on a table top or the floor and will be able to feel and see if it wiggles.
If you plan on using the PUMPKIN PUNCH year after year, make sure to recheck these drill bits to make sure they don't get bent. Even a slight warp in the steel rod will throw off your axles.
Step 6: PUNCHING AXLE HOLES:
To punch the axle holes, hold the pumpkin up against the punch and just drill through, or push through. Make sure to keep the first rod in place when drilling the second axle hole.
Step 7: FINISHING TOUCHES
Check to make sure the drill bit you made will fit in each hole.
Lightly sand the drill holes to avoid splinters.
I would use a clear sealer to keep the steel from rusting.
Now you are ready to make a PUMPKIN RACER. Check out the Instructable called HOW TO BUILD A PUMPKIN RACER...
SEE YOU AT THE RACES :)