Han Solo frozen in Pumpkinite

This was totally just a fun experiment to see what would happen when you try to 3D-carve a pumpkin with a CNC machine. It got pretty messy but I think it turned out kind of interesting.

Check out the quick Instagram video here, thank you for following! https://www.instagram.com/p/BpYRPZ6A7_h/

If you have any questions after reading my Instructable, please feel free to ask in the comments. Happy Halloween!

Supplies

Flat-ish Pumpkin (try and find one with a really flat/compressed side)
Pumpkin Carving Tools (Knife, Scooper)
CNC Machine (any sized machine could be used really - it all depends on the size of your pumpkin!)
3D Model (you could also cut out any vector file - this experiment just happened to use a 3D model)
Autodesk Meshmixer(Free Software to prepare and modify the original 3D model)
Vectric Aspire(The software I used to convert the 3D image into a GCODE file that my CNC machine could process and cut out of the pumpkin)

Step 1: Choose a 3D Model or Vector Pattern

The sky's the limit on what you can carve with a CNC machine!

Literally any 3D model or vector pattern could work.

For my first attempt at this, I thought it would be fun to try and make a Star Wars themed version of the iconic "Han Solo Frozen in Carbonite".

I'll be using the 3D model of Han Solo attached as an STL file to this Instructable step.

Han_Solo_in_Carbonite_MAX.stl
Download View in 3D

Step 2: Prepare Your Pumpkin for Cutting

As you wander through the pumpkin patch, try to find a deformed pumpkin that is more flat than round on at least one of the sides. Sometimes if they've been growing against another flat surface they can take the shape of that surface. You might even get to take a flat one home for free as most people probably don't want a flat pumpkin (little do they know....haha).

Step 3: Clamping Down Your Pumpkin Slice

I found a scrap piece of MDF that I'll be using as the platform to mount the pumpkin slice to. To prevent it from getting soggy and wet, I placed a piece of wax paper on MDF before adding the pumpkin slice.

Position the pumpkin slice on to the platform and make sure your CNC machine will be able to get at it.

I found some long and thin pieces of scrap wood to help clamp down the pumpkin slice in place so that it doesn't shift around while being cut. Screw in the wood "clamps" just enough to add firm pressure on the sides of the pumpkin, but not so tight that it damages the pumpkin surface.

We'll then be clamping this MDF board assembling on to the CNC work area using t-slot clamps.

Step 4: Preparing the 3D Model for Cutting

First measure the pumpkin “work area” of the slice so that we can represent it on the computer and input the measurement values into the CNC software.

Next I'm Using Autodesk Meshmixer (free software) to modify my STL file and create a model that will fit 'inside' my pumpkin slice. The rectangular grey block you see represents the area/volume of the pumpkin slice.

I placed an oval shape into the block and then subtracted the oval area from the block to better represent my cutting area.

I then superpositioned Han’s cut out face into the domed cavity that we just substracted.

In order to meet the height restrictions of my CNC machine, I had to squish Han’s face a little bit so his nose would be flush with the highest surface.

Using Vectric Aspire CNC software (not so free), inputted the new 3D model and simulated a 3D cutting path.

Since the pumpkin is so soft, we can do the entire path in a single pass (no excavation paths necessary!) Now we’re ready for cutting...

Autodesk Fusion 360 should be able to do 3D cutting paths as well (I just haven't tried it out yet!). If you have a good tutorial or tips on how to do it, please let me know in the comments.

Step 5: CUTTING THE PUMPKIN

It's time to cut out our design on the pumpkin! This is by far the most exciting part.

Since pumpkins are mushy I knew things would get messy pretty fast. I preemptively laid down pieces of plastic and garbage bags surrounding the cutting are so that my CNC wouldn't get covered in wet pumpkin matter - this turned out to be a really good idea because pumpkin splashed everywhere :P

I clamped down the MDF platform piece on to my cutting table and set up my spindle with a 1/4 inch BALLNOSE cutting bit. Ballnose bits are the best for cutting out 3D carvings. The smaller the bit, the higher the detail in your carving.

I hit the START button and watched the pumpkin pieces fly everywhere.

Step 6: Display Your CNC Carved Pumpkin

I used compressed air to spray off all the bits of pumpkin and reveal Han's face underneath.

I then placed the pumpkin wedge back on to the original pumpkin that we cut it out from. To affix the pumpkin slice back on, I screwed it on from the BACK side of the pumpkin so that the screws were not visible from the front (used 4 deck screws). The only thing missing are two leaf-filled gloves sticking out underneath to be Han Solo's hands.

Okay so squishing Han's face made it look a bit less like him....but I think the experiment worked. What do you think? Let me know any comments or ideas you may have. When my mom first saw it, she thought it was Donald Trump....LOL.

For a quick video showing the entire process, check out the Instagram Post here:
https://www.instagram.com/p/BpYRPZ6A7_h/

Don't forget to follow me on Instagram for more crazy CNC projects! Thanks for reading my Instructable and have a terrifying Halloween!!!