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In this instructable, you will learn several common and less common procedures in cucurbita surgery. These include:
-lobotomy
-plastic surgery
-construction and use of an artificial brain
-cryogenic preservation.

And now that Halloween is over, I have added a postmortem examination. Read it before attempting to duplicate any of the procedures outlines here.

Step 1: Setting Up Practice

You'll need different materials and tools for different processes:
For the lobotomy you'll need a knife and a spoon.
For the plastic surgery you'll need a sharpie and a knife.
For the artificial brain you'll need a large LED, a CR3202 battery, wires, a reed switch (optional), and a soldering iron.
For the cryogenic preservation, you'll need steel wire, pliers, a pumpkin-sized vessel (mine was a water pitcher), a roll of pennies, a large pot to boil water, water to boil in a large pot, and something to boil a large pot of water with.

And of course you'll need a patient. Select a pumpkin that will be easy to work with; I have one of those small round ones, but if you're feeling adventurous, you may learn on a larger pumpkin.

Step 2: The Lobotomy

Around Halloween, the lobotomy is one of the most popular procedures. Begin by taking an appropriate knife (not longer than the pumpkin, sharp, etc.) and stabbing the pumpkin repeatedly in a ring around the stem. Try to line up the angles so that the cuts all connect, and make your ring a little lopsided so you'll be able to replace the stem without confusion.

After the stem is removed, you'll need to scrape the brains out of your pumpkin with a spoon. Set them aside, because there are complicated rules for disposing of delicious things.

Step 3: Disposing of Brains

Brains are in fact, quite delicious. There are probably any number of ways to dispose of them, but I recommend rinsing them in cold water and toasting them with salt.

Step 4: Plastic Surgery

Most pumpkins do not have very expressive faces, so plastic surgery can really bring out their features. First, outline the changes to be made with a sharpie or similar tool. I chose a nice and simple ("classic") face for my pumpkin, and it came out quite satisfactory.

Then trace the sharpie lines with a knife and remove the extra material. You may find it helps to work in layers and not cut all the way through, and to start with a slightly smaller hole than planned and then widen it. Cleanup is easier if the carving is done on newspaper.

Step 5: Construction of an Artificial Brain

Great advances in technology have allowed us to build an artificial pumpkin brain. Because the natural pumpkin brain is so simple (most pumpkins don't even have one), an artificial pumpkin brain can be constructed safely in a home workshop.

My pumpkin's brain is a simple circuit consisting of a blue LED, a CR3202 battery, and a reed switch. You may prefer to leave out the reed switch, but it eases the cryogenic preservation process we will practice later. You may find it helps to diffuse your LED.

Step 6: Installation of an Artificial Brain

Position the brain inside the pumpkin with the LED facing the face. If you have a reed switch, run the wires out next to the stem, on the side facing away from the face.

If necessary, turn it on to test the fit.

Doesn't he look brighter already?

Step 7: Cryogenic Preservation

But wait, how can you ensure that your handiwork, and your patient, will survive until the big night? By freezing them solid in a block of ice!

First, we prepare some cryogenic fluid by boiling a big pot of water. Boiled water freezes clearer than unboiled water, and you get to call it "cryogenic fluid" when you're done. Pour maybe an inch of cryogenic fluid into your pumpkin-sized freezer-safe container, and freeze it.

While we wait for bottom to freeze, we will prepare the pumpkin for its preservation. Because pumpkins float, cover the bottom of your pumpkin with most of or all of a roll of pennies. Be careful that you don't disrupt the artificial brain if you opted to use a switch in yours.

Next, make a small collection of perhaps a half-dozen cucurbita staples. These are short pieces of wire or perhaps paperclip, formed into an angular "U" shape with pliers. Use them to secure the stem to the main pumpkin so that it does not float, to fix the artificial brain in place, and to rein in any stray wires. It will probably be necessary to use pliers to insert them in the pumpkin as well.

When the cryogenic fluid in your pumpkin-sized container is frozen, place the pumpkin in it away from the sides and pour in enough cryogenic fluid to submerge it. Even lukewarm cryogenic fluid will begin to melt the already frozen layer, so be sure freeze the container quickly.

Step 8: Notes

Things I wish I had known before I did this project, but now know anyway:

-While it may seem like a good idea to use a battery holder when making your artificial brain, expanding ice will break the contacts with the battery. Solder directly to the battery instead.

-Water boils much faster if you cover it, but cools more slowly. But if you remove the cover to cool it, it evaporates rapidly.

-Water cooling from boiling in a large pot will take a long time to cool, but water cooling from boiling in many small metal pots will probably take less time.

-Placing the pumpkin in cryogenic fluid will result in many small and a few large bubbles coming out of it. This may or may not be responsible for the cloudier water at the top, but pouring the fluid in around the pumpkin will hopefully give better results.

As a consequence of my inexperience, the cryogenic preservation rendered the artificial brain inoperative. Whether or not I repair mine, I hope you will learn from my mistakes.

Step 9: Thawing and Postmortem Examination

Now that Halloween is over, I thought it best to thaw the pumpkin and see what went wrong.

First of all, Cryogenic preservation created a set of interesting fissures in the subject. I expect this was because the ice found it easier to tear apart the pumpkin than the pitcher it was in.

As expected, freezing took a toll on the artificial brain. The battery clip was a major part of the problem, but not because expanding ice separated the contacts as I had supposed, but mostly due to corrosion. Again, I would solder directly to the battery if i had a second chance to do this, and I would reinforce the connections with epoxy or hot glue (suggested by JakeTobak).

The other problem with the artificial brain was that the reed switch shattered. I was afraid of this, but willing to try. There is a possibility that it remained functional while frozen, however I would not lose another switch to test this theory. Unless you can protect the reed switch in the freezing process, I would suggest using an old fashioned switch set apart from the ice, perhaps mounted on the ice afterward with a little work.
Fruit should never looked surprised! XD
If you have something to vibrate against the side of the pitcher, you can probably get rid of some of the extra little bubbles.<br/>Also, a battery holder should work if it's water tight, if water is getting into the battery holder it would probably short and not work anyway.If you're gonna just solder the wires directly to the battery, like you said, you would want to maybe put something around all the joints to make them water tight. Hot glue or epoxy might work. I know batteries + fire = bad, idk if they act weird when frozen though.<br/>One other option might be to have the leads from the LED inside the pumpkin go out of the block of ice and have the power source not be frozen.<br/>
Purified water (not 100% if boiling is good enough) is actually not conductive. And even if it was, the resistance of the water is greater than through the LED, so it shouldn't have been a problem.<br/><br/><a rel="nofollow" href="http://answers.yahoo.com/question/index?qid=20080805025252AA5mzwc">http://answers.yahoo.com/question/index?qid=20080805025252AA5mzwc</a><br/>
Sorry, I meant &quot;not *very* conductive&quot; especially to DC current.<br/><br/>And the rapid corrosion that Ian experienced was because de-ionized water dissolves metal, especially good conductors like copper or silver.<br/>
Thanks! I was unaware that de-ionized water did that.
Thanks for the suggestion, I'll try it if I get a chance. I think it was the battery holder, it was only a clip, not very watertight or anything. I don't quite understand the reason for epoxying the joints, except maybe if the freezing ice broke the solder? Looking at the CR3202 spec sheet, they should work fine when frozen. I had considered something similar only running the switch outside the ice though. I'll keep that in mind if I can't make it work any other way though. Thanks for all your help, and if I have a free afternoon before Halloween, or perhaps after, I'm planning to thaw out the pumpkin and troubleshoot the circuit. My only concern is that freezing and thawing the pumpkin may turn it into a mushy pulp.
The pressure from the ice forming was definitely an issue. Potting the entire artificial brain in epoxy would probably prevent all of the draw-backs that you experienced. Perhaps two pots, one for the LED and battery, and another with the switch (so you can put it near an edge. The insulation around the wires will probably prevent the water from dissolving the metal wire for quite a while (probably longer than the battery would last. You might also be able to create a small box hotglued to the inside of your bucket or pal that you put the battery (or even the entire circuit with the LED on long wires inside the ice) in so you can change it if needed. Hot glue the LED wires going into the box, too. This should prevent the water from going in there and freezing, too.
Hilarious writeup! Great project idea too...frozen pumpkins definitely stops people from stealing them as easily :D Not sure how long they'll last though pre-Halloween.
Thanks! I'm keeping it in the freezer until Halloween, and it'll probably be around if not below freezing where I am.

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