Introduction: Laser Cut Cake!!!

In this instructable I'm going to show you how to make a multi-layer cake using CAD and rapid manufacturing.

(I personally get a huge kick out of mixing heavy machinery with cake baking.)

One of the coolest tools on the planet is a laser cutter. It is normally used in industry to cut plastics, wood, glass, or thin sheets of metal. But, the tool is so versatile that you can also use it to pattern things like chocolate, pumpkins, Silicon wafers, paper, rubber, cork, or in this case... CAKE!

By using the laser to cut the cake we can do arbitrary design on the computer and then transfer that virtual design into an actual physical cake. It's really cool. And tasty!

I was inspired to make this particular cake for the Engadget Birthday Contest.

Step 1: Tools and Ingredients

For this project you will need:

  • Cake Mix (Preferably White or Yellow Cake). I used Duncan Hines
  • Some sort of frosting. I used fresh whipped cream.
  • Food coloring for the frosting.
  • And a Laser Cutter!!!

Admittedly, these same process steps can also be applied to cutting cake using a CNC Mill, a waterjet, a scroll saw, a band saw, or even by hand. The laser just makes it much easier.

Step 2: Bake a Cake

You can get fancy when making your cake, but I was looking for simplicity (since I was planning on making a lot of cake to test on.)

I used an off-the-shelf cake mix, and made several chocolate, white, and yellow cakes.

But, I didn't follow the recipes exactly.

You see, in order to laser cut and then assemble our cakes there are several things that we need to do.

First, we need to make the cakes thin. If the cakes are too thick then the laser will heat up the edges too much while cutting and we'll end up with burnt cake, (yuck.) In order to reduce the thickness of the cakes you can simply use larger cake pans then the recipe calls for. In my case I used two 13" x 9" cake pans rather than two 9" x 9" cake pans.

Secondly, we need to make the cakes robust. Normally cakes are delicate and fluffy which is all well and good, but we're going to be manipulating our cakes so we want them to stand up well. In my case I increased the cake strength by reducing the amount of water in the recipe from 1 1/3 cup down to 3/4 cup. This also had the added benefit of reducing the moisture in the cake which led to better cutting by the laser.

After much testing I came to the conclusion that the white cakes are best suited for laser cutting. I'm not entirely sure why this is, but I would guess that it has to do with the fact that there is significantly less fat in the white cake recipe (less oil and no egg yolks.)

Step 3: Transfer to Cutting Sheet

It's easier to deal with the cake later on if you remove it from the baking pan and place it on a nice thick piece of card stock. The cake shouldn't stick to the paper very much.

Step 4: Do Test Cuts

Whenever cutting a new material on the laser cutter you need to do some test cuts. And that's quintuply true when dealing with something as variable as cake. I found that each cake cut slightly differently, and different types of cake cut drastically differently.

There are two main conflicting things that you want to achieve when cutting through the cake. You want to make sure that you cut all the way through, and you want to avoid burning the edges of the cake as much as possible. Cutting all the way through means lots of power, avoiding burning means less power.

The solution is to use numerous passes at high speed and low power. By cutting repeatedly you can slice off a little bit of cake with each cut and avoid burning the edges. You can't scale up this approach infintiely, but for these thin cakes it works reasonably well.

For my particular laser cutter and cake I found that these settings worked quite well:

12 passes
600 dots per inch
100% Speed
60% Power

Step 5: Create Pattern

I used Corel Draw to create the pattern that I wanted for my cake. This is one of the most powerful aspects of rapid automated manufacturing. You draw your ideas on the computer screen and then through the magic of technology those ideas get fabricated in real physical objects. In this case... cake.

After determining your final design, split the layers apart and arrange them in such a way that you can cut the maximum number of pieces out of a single cake.

Step 6: Cut Cake

Okay, here's where the fun really begins. Load your cake into the laser cutter, get everything positioned correctly, load in the parameters that you determined earlier by doing test cuts, make sure your compressed air is on and you've got a fire extinguisher handy, and then... Hit Go!

Take pictures while the laser is doing its thing.

Step 7: Remove Escess Cake

Once you've lasercut your cake you have to remove the excess cake that is surrounding your beautiful pattern. I recommend using a knife to cut perpendicular cuts in towards your pattern from the edge of the cake and then removing the pieces one at a time. Be gentle and careful, this is where you're most likely to break something.

This is also a good time to put all of your layers together briefly and make sure that everything fits together correctly.

Step 8: Make Frosting

All cakes need frosting, even if they're cut with a laser. For my cake I used fresh whipped cream colored using standard food coloring.

  • Cyan == 4 drops of Blue
  • Pink == 14 drops of Red
  • Orange == 8 drops of Red and 8 drops of Yellow

Step 9: Frost Cake

Carefully frost the cake. You can either frost the edges or leave them exposed depending on your tastes.

In my case I frosted the layers after removing the excess cake. Alternatively you could try frosting after lasercutting but before removing the excess. This would probably lead to nice crisp edges on your frosting. Or, the other thing that I played around with briefly is frosting the cake before laser cutting. It could work well, but if you have too much frosting it has a tendency to melt and flow under the laser.

Step 10: Combine Layers

After frosting all of the layers it's time to put everything together. Because the cake was baked to be robust it should be pretty easy to move the pieces around. Clean up any smudges, and...



Step 11: Consume

And of course, the final and best step.

Getting to eat it!

The laser leaves behind a very faint taste of burned sugar which seems to remind people of marshmallows cooked over a campfire, but it's still super tasty! Bon apetit!

I'm going to try baking a number of cakes using this method and I'll post additional instructables to document the process.