3D Printed Gingerbread House

Okay, perhaps the title is slightly misleading, but it worked, you’re here. Rather than explicitly 3D printing a gingerbread house we will be designing the necessary cookie cutters in a Computer Assisted Drawing (CAD) program before 3D printing the necessary parts, baking the biscuits, mixing the icing and creating four gingerbread houses.

This is my first instructable and has been entered into the “First Time Author” competition.

I’ve always enjoyed the process of creating an edible creation that has a story behind it and these gingerbread houses are no exception. We already had some gingerbread house cutters in the cupboard but when assembled these gingerbread houses are quite large. I wanted the fun of creating a gingerbread house but also wanted to do it on a smaller scale. Making it much easier to create many houses with a single batch, meaning that you have more to give away and you can easily try different styles for each house. If you find a style that you really enjoy it wouldn’t be hard to scale up each part and design a bigger scale house with this same style. My aim for this instructable is to show you the process I followed to create my gingerbread houses and the necessary files, but I would also like to provide enough descriptions so that you can design your own houses from scratch.

I believe that each step should contain enough images so that you can figure out what each stage of the project should look like. If you think that a photo might be missing please let me know. All dimensions are in millimetres for this Instructable.

Step 1: Materials & Ingredients:

To create the Biscuit Cutters:

• Clear/White PLA filament (another colour of PLA should work here)

To create the House Bases:

• 5mm plyboard
• Alfoil

To make the Gingerbread Biscuits:

• 125g butter
• ½ cup castor sugar
• 1 egg
• 2 cups plain flour
• 1 tsp bi carb soda
• 2 tsp ground ginger
• 2 ½ tbsp golden syrup

To make the Royal Icing:

• 1 ½ cups icing sugar
• 1 egg white
• ½ tsp lemon juice

To decorate the Gingerbread Houses:

• Mini m&ms
• Mini smarties
• Liquorice bullets
• Wonka Nerds
• Fruchocs

Step 2: Step 1: Designing the Biscuit Cutters

The aim for this step is to design the necessary biscuitcutters using CAD software, I used Autodesk Inventor but any CAD software would work just as well. If you are currently a student, you can get a free 3 year license for Autodesk Inventor or Fusion360.

https://www.autodesk.com/education/free-software/inventor-professional

If you plan to use my created STLs you can skip this step and just use the STLs attached to this step.

The first step was to determine how big I wanted my final product to be, to do this I drew up a rough template on a piece of paper to the approximate dimensions that I wanted and then used these dimensions to create the parts within CAD software.

I based my cutters and dimensions on the end drawn on paper. I drew a rectangle and then used lines to create the top triangle of the house, this creates the main shape of the end piece. These shapes were extruded 1.5mm to create a firm surface to press on while using the cutters. I used the offset tool to create the cutting edge of the cutter, make sure that the dimension that you use for this is a multiple of your nozzle thickness, for example, my nozzle thickness is 0.4mm so I used 1.2mm as my offset value (a multiple of three extrusion widths, this could be decreased to 2).

This cutting edge was then extruded the approximate thickness of the final gingerbread dough that you plan to cut. I initially did quite a large thickness for this but found that it wasn’t necessary, 6mm should be plenty. I added some fillets on to make some of the corners look a bit neater, but this won’t have a large effect on your result.

An optional step that I didn’t do would be to add an additional cutter at this point for the door or a window. This could be done by following the steps above but in the centre of the roof, side or end pieces. Draw a rectangle/square, create an offset and then extrude this the same amount as the external cutter.

The next and final step isn’t entirely necessary but can decrease the total amount of filament used and the overall print time. I created a sketch leaving 1.5mm between the cutting edge and the sketch, I then cut out some shapes to decrease the amount of time/filament required on the first layers.

This same process was then followed to create the side and the roof pieces except that these are composed of simple rectangles. I used the same cutting-edge and thickness dimensions for these pieces as well. The roof piece was slightly longer and wider and longer than the side cutter so that the roof overlaps the edge of the house. These widths and lengths for the roof cutter were determined from the diagonal of the end piece.

Step 3: Step 2: 3D Printing the Biscuit Cutters

This step requires access to a 3D printer, or another means of creating the 3D printed parts. You may be thinking, won’t using 3D printed parts introduce unsafe bacteria to your food? Yes, there is a chance that if you used then washed these cutters than used them again that the risk of bacteria may increase. I designed these cutters as single use parts and as the food is getting cooked in a hot oven after touching the cutter, I decided that in this case the risk would be minimised. To further decrease the risks, I used PLA (plant based) instead of ABS (petroleum based) filament and a lighter colour of filament as the addition of colours can introduce other chemicals into the filament. There are other means to make printed parts safer and these can be read about in the website below.

https://all3dp.com/1/food-safe-3d-printing-abs-pla-food-safe-filament/

My cutters took two attempts to print acceptably and are slightly different to the designs above as there were unnecessary elements in the cutters I used. You shouldn’t need a very high infill percentage for these cutters as there are no aspects of the cutters that need to be incredibly strong.

Step 4: Step 3: Making the Bases (designing the Template)

The aim for this step is to create the bases for the gingerbread houses to be built on. Because I enjoy using CAD software, I decided to also design this within Autodesk Inventor. Firstly, I took the printed cookie cutters and again used a piece of paper to get some rough dimensions for the bases. After obtaining these dimensions I created a sketch using CAD. Rather than extruding this and 3D printing a template I created a drawing with a 1:1 scaled version of my sketch. To do this I created a new drawing file, changed the page size to A4 and attached a base view of my sketch with a 1:1 scale. This was then exported and printed as a PDF.

Step 5: Step 4: Making the Bases

The aim for this step is to create the bases out of wood and Alfoil. After printing the PDF I cut out the sketch so that it could be easily used as a template for basic woodworking. I traced the template onto a piece of 5mm plyboard (acrylic or thinner wood would also work for this step) before using a bandsaw to cut out the basic shape of the base. An electric sander was then used to achieve the desired curves of my template. After cutting one base you can trace this to get the desired shape for the other bases.

I created four wooden bases before I used Alfoil to cover them, this makes the bases food safe and the alfoil can easily be removed for storage. Remember to have the dull side of the Alfoil touching the wood leaving the shiny side to be viewed from the top. To do this I cut a piece of Alfoil that would fit over the base with some to spare before folding the Alfoil over each edge and taping it to the wood. To allow the curves of the base to be seen I turned the base upside down and pressed the Alfoil against the curve before putting on another piece of tape, this looks a bit rough from the bottom but looks better from the top.

Step 6: Step 5: Making the Biscuits

The aim for this step is to make, cut and bake the biscuits required to make the gingerbread houses. For this step I decided to use my mum’s trusty gingerbread recipe which only has 8 steps. You will be working with food in this step so make sure you’re your hands have been well washed. The required ingredients can be found in the materials & ingredients step or the attached PDF can be used.

Steps to make the gingerbread biscuits:

1. Soften the butter and combine with the castor sugar until creamy.
2. Add the egg to the butter and castor sugar before combining well.
3. Sift all the dry ingredients (plain flour, bi carb soda and ground ginger) and warm the golden syrup in its original container to make it easier to pour.
4. Gradually add the sifted dry ingredients and the warmed golden syrup until all combined.
5. Turn the oven on, 180°C (356°F) and make up several trays with baking paper, I prepared three.
6. While the mixture is still in the bowl coat with a light layer of plain flour so that the mixture is less sticky. Remove from bowl and knead lightly before rolling mixture out to approximately 3mm (mine were thicker than this but this will make the mixture go further).
7. Cut out two of each shape per house; two ends, two sides and two rooves. I cut out enough to make four houses but if you can make more go for it! With the small excess of gingerbread that I had left I cut out some random shapes, these won’t be used for the gingerbread houses, but they taste great!
8. Place the cut biscuits on the pre-prepared tray before cooking in the oven for 12 minutes or until golden brown. Now you’ve made all the main parts of the gingerbread house.

Step 7: Step 6: Making the Royal Icing

The aim for this step is to make the icing required to ‘glue’ all parts of the gingerbread house together. This is quite a simple recipe where the most difficult part is to separate the eggwhite from the egg yolk. I used an egg divider, but you can use your hands or the eggshells (https://www.wikihow.com/Separate-an-Egg). The required ingredients can be found in the materials & ingredients section or the attached PDF can be used.

Steps to make the Royal Icing:

1. Separate the egg so that you have just the egg white (the egg yolk could be used to make custard)
2. Lightly whisk the egg white and the lemon juice together in a small bowl.
3. Gradually add the icing sugar, whisking until smooth and combined (you could add a colour at this point and add a bit of extra icing sugar but who wants yellow snow?)
4. After the mixture is combined, pour it into a small snaplock bag.

Step 8: Step 7: Making Part of the House

The aim for this step is to begin to create the final product, the ginger bread houses! This is the fun part and the time where you get to see your creation and all your hard work come together.

At this point I would wash your hands again as for stages of this you will have to touch each lolly individually and you do not want germs on the lollies.

The first step is to cut the corner of the snaplock bag, this will determine the width of your icing so try to cut off a relatively small amount. Lay the bases out and place the required gingerbread components next to each base, try to make the roof and sides parts as similar as you can when you allocate the parts for each base so that the houses look uniform when completed. Not all my pieces were perfect rectangles, so some had slightly different dimensions.

Pipe a rectangle of icing onto a single base, use the side and end pieces to determine how big this should be. I then piped two lines of icing down the ends of gingerbread house, these will attach to the two side pieces. Place an end on the piped rectangle before placing the two side pieces and the other end piece. I found that at this point the house essentially held itself together but if you find that yours doesn’t, place an object at each end of the house so that it doesn’t fall apart while the icing hardens. Follow this same process for each base that you made.

Step 9: Step 8: Decorating and Completing Your Gingerbread House

The aim for this step is to completely decorate and complete your gingerbread houses. The materials listed for this in the materials & ingredients section are all optional, if you have other lollies around the place you are more than welcome to use them. The items listed are simply the ones that I decided to use.

You could stick your roof on first, but I decided to ‘tile’ my rooves and this was easier to do without the rooves attached to the houses. To ‘tile’ my rooves I first sorted my mini m&ms or smarties into colours, this made it quicker to tile the rooves with set patterns. Next, I grabbed a mini m&m or smartie, piped a bit of icing on and attached it to the roof in the desired pattern. After fully tiling all the rooves I set them aside to ensure that the icing hardened before attaching them to the main house.

At this point you can continue to decorate the houses as you please, I went for a winter theme despite being in sunny Australia. I had piles of wood at the front of the house made from liquorice bullets, I traced an outline of a door and added an m&m as a door handle and then created a path leading up to the door, this was made from nerds or mini m&ms/smarties.

I planned to give at least one of these houses away and I knew that that person’s favourite lollies were fruchocs so before attaching the rooves I filled the interior of the house with fruchocs as a little surprise.

The final step is to attach the rooves, this was performed by piping two lines of icing along the diagonals of the end pieces and attaching the rooves. Some rooves were happy to stay there after holding them for a bit, but others needed to be supported to allow the icing to harden. You have now created your masterpieces!

Step 10: Step 9: Using Up Your Remaining Ingredients

If you’re anything like me you have some leftover biscuits, lollies and icing. Before being told to chuck the leftover icing into the bin I would recommend grabbing the extra biscuits that you made with the leftover gingerbread mixture and decorating them. At this point I’d eaten most of these, so I pulled a packet of Arnott’s Marie biscuits out of the cupboard and decorated these to use as much of the icing as I could before chucking out the leftovers.

Step 11: Conclusion:

You have now created several gingerbread houses using a 3D printer and some creativity! I hope that you enjoyed this project as much as I did and that you enjoy eating your creations! Please post pictures of your creations so that I have more style ideas when I make these next. Let me know if there are any changes that could be made to this instructable to make it better.

References:

• https://www.autodesk.com/education/free-software/inventor-professional
• https://all3dp.com/1/food-safe-3d-printing-abs-pla-food-safe-filament/
• https://www.wikihow.com/Separate-an-Egg
• https://www.taste.com.au/recipes/royal-icing/a1523405-3d42-49f1-936d-d927812cecf5