Hi, this is Ed from Other Machine Co. and I like sci fi.
Star Wars is great and all, but it's even better when combined with chocolate. Thus, the chocolate Millennium Falcon! Fly it around for a bit of a space battle before eating it up. Pew pew nom nom.
Step 1: Tools and Materials
Step 2: Make or find a model
With lots of people making things and sharing them online, I didn't have to model my own Millennium Falcon. I found this Millennium Falcon by Glitch on Thingiverse.
This model is broken up into three pieces to make it easier for 3D printing. You can download them all, but I'm only using the top two pieces since this will be a one-sided mold.
Step 3: Prepare model in Meshmixer
Meshmixer is a great free tool for tweaking STL files. It's perfect for what we need to do here which is to combine the two STLs into one. Here's what I did:
Attached is the Meshmixer file so you can see what those results look like as well as the exported STL file.
Step 4: Starting on toolpaths
Now that thereís an STL that works as a piece of chocolate, we need to create toolpaths. Toolpaths are the instructions that move an end mill around in 3D space in a CNC machine. These toolpaths depend on things like the type of material youíre cutting into, the spindle speed, and the smoothness of finish that you want.
To create these toolpaths, Iím using MeshCAM (free for 15 days, $250 after). I'm going to be creating a roughing toolpath and a finishing toolpath. The roughing toolpath clears away most of the material and uses a larger end mill: a 1/8" flat end mill. The finishing toolpath uses a smaller end mill: a 1/16" ball end mill.
The first thing to do is load up the STL file for the Millennium Falcon from the last step. The units for the file are in mm. Choose the 3-axis milling option.
Once the STL is in, it needs to be scaled down. I'm milling this out of a piece of wax that is 3" x 3" or 76 mm x 76 mm. Since I want to have a little space between the positive shape and the edge of the wax, I want a maximum dimension of 70 mm. So just choose the scaling option and scale it all by 0.73.
Step 5: Setting up material for toolpaths
The model is now ready to go, so now the material needs to be determined.
You're now ready to create toolpaths.
Step 6: Making toolpaths
Now that everything is sized up and placed, it's time to set the settings for the toolpaths.
Step 7: Saving tooplaths
You will see a list of checkboxes. This combines all of the toolpaths, including the roughing and the finishing. Since we're going to be using different end mills for these two processes, we'll need to save them as different files. This can be done by choosing which toolpaths get exported as your file.
Step 8: Edit G-code
Unfortunately, MeshCAM doesn't include the instructions in the G-code to start the spindle at the beginning and stop it at the end. Lucky for us we can use a basic text editor to fix it!
You will want to add these two lines in the beginning of the file:
This starts the spindle (M3) and sets the speed to 12,000 rpm (S12000)
At the end of the file, add this line:
This stops the spindle
Step 9: Machining wax
Now that you have the G-code for the job, it's time to get started on the Othermill.
Step 10: Otherplan
OK, now it's time to get started on Otherplan, the software for the Othermill.
Step 11: Insert end mill
Step 12: Mill!
Now that everything is ready to go, select "Cut" and then "yes" to get started. The Othermill will start spinning the end mill and go to work on the roughing toolpath. Be ready for lots of wax shavings.
Once the roughing is done, clear out the inside of the Othermill with a vacuum and get ready for the finishing toolpath. The process of setting up the tool and path is just like the roughing toolpath process.
When that's done, your wax Millennium Falcon will be ready for some mold making.
Step 13: Making a mold
Double check your wax positive to make sure that it's completely clean. Then check again.
OK, now time to make a mold. We're using Copyflex Liquid Silicone.
Since this piece isn't that detailed, we skipped step 3, but it would be needed for more ornate pieces. Pouring from 12 inches helps to reduce the amount of bubbles. The silicone stretches out as it falls and helps to get rid of the air that was mixed in when stirring. This is called a "stretch pour."
The Copyflex cures in about four hours. You now have a mold!
Note: The item being molded in the picture is not the Millennium Falcon.
Step 14: Making chocolates
You'll want tempered chocolate for making the final pieces. You can make this on your own, and it can easily be done by following one of many tutorials out there, but we took a shortcut and used these Ghirardelli Chocolate Melting Wafers. The process is essentially this:
These chocolates set in about an hour in our fridge.
Step 15: Pew pew nom nom
You've made a chocolate Millennium Falcon! Pew pew!