3D Printed Toy French Fry Train

I am a high school student at Benicia High School, for my design I made a children's toy train in the shape of french fries. This project was part of my engineering class, I used Fusion 360 to model the design and a 3D printer to print out the prototype and finished build.

The thinking behind this project was how will a young children interact with the toy, what will interest them, and how will the toy be handled?

The steps that I used was

1. Find inspiration for how the project will look
2. Find out what is the average size of a toy train
3. Design the different parts with the measurements
4. Print out a prototype of the full train
5. Assemble the prototype and check to see if the train needs adjustments
6. Go back to fusion then edit the parts
7. Print out the final parts
8. Assemble the finished build attach the wheels

• Fusion 360
• Cura Printing software (or any other printing software you use)
• 3D printer
• Nails or rods
• Nails
• Pins

This project was for my engineering class and our task was to create a toy train that's also compatible with Thomas the Train toys and their track. Each group had to come up with their own theme for their trains and scale it to the correct scale as the Thomas the Train trains.

The theme that my group went for was food. So I thought of something that most kids really like. And I was thinking of french fries in a red box. I thought back to when I would get french fries in the past, what kind of box they had, their shape, and the number of fries that were included.

Next, I researched what different kinds of boxes that fries came in and combined that with how this will look and work in Fusion 360. I came up with a rectangular box with a slope in the front of the box and a curved inside to accommodate and arrange the fries at varying heights

So before I started sketching I looked at a few different-sized trains from The Thomas the Train Set. Wrote down their measurements for reference. After all these measurements were done I ran into a problem.

Some of the trains that were part of the set were around 5 to 7cm in length and were able to make turns on the track with ease and needed no extra mechanism. As for the bigger trains around 10cm and above, these trains had almost like skateboard turning trucks to rotate the wheels on turns in the track.

So I decided to make my train smaller in length and avoid the use of trucks for the wheels. Here are my initial sketches for the train.

In Fusion 360 since we had to base our measurements of the trains off of the measurements of the train from Thomas the train. The measurements were done in a similar way to this train that we used (under text)

The Fusion model that I made was similar to the image of the green train from Thomas the Train, except without the use of trucks by using a smaller body. The questions that I asked when modeling the parts were:

1. Do the parts as similar to the example train as possible
2. Make sure all the pieces are down to scale
3. How will these pieces connect or interact with each other
4. Will the other parts that are not 3D Printed be accommodated

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I decided to start off designing this piece because this piece is the main part of the foundation for the whole train. I had to incorporate different aspects to this piece compared to other pieces. Like using the correct measurements to have the axles fit to let the wheels turn. And secondly, placing the holes on the front and back to allow magnets to connect all of my group's trains together. Lastly, incorporate a way to have the base fit the box to have the least amount of friction and without the use of glue.

When designing the wheels I used the measurements from the wheels from The Thomas The Train set. This is to have the wheels be able to fit the toy track and have all the wheels be compatible and work with all the rest of the trains. The component that this part had to fit with was nails that I used as axles. Here is the link for the nails that I used for the axles

This box is used to house the fries and is one of the most recognizable with french fries. With all of this information in mind, I put a well-known curve on the front of the box that is seen on many french fry boxes in the real world. When designing the box I ran into a problem, how will the fries sit to be angled like a real french fry box? In my research, I found out that french fry boxes have a curve at the bottom of that box to make the fries look more presentable. Knowing this information I incorporated a slight curve at the bottom of the box to have the fries arranged in a curve.

For the french fries, I had to put into consideration that they have to fit in the box and be able to have different orientations. For this, I took inspiration from children's toys that we're able to come apart and be put in different orientations to look different. To achieve this I put two different angles on either side of the fry, this was to have one side look different from the other. And having all the fries their own piece then being a single piece, letting each fry move freely.

The software that I used to print my Fusion 360 model was Cura and the printer that I used was the Ultimaker 2+. In Cura, I made sure to adjust the settings of the printer to the correct settings to get the best quality print. For instance like adjusting the layer, temperature, speed, and if the piece needed support. Using the slicer I was able to see how the print was going to turn out.

Some tips I suggest for printing even if it's not for this specific design is to rotate your piece in a way that has the least amount of support. This is one good for saving on materials, but also removing and having a clean final print. Also if the piece that you are printing is going to have a lot of pressure on it, I would recommend increasing the infill to make them stronger and more sustainable.

Step 7: Assembling

The end result of the project was very rewarding. I had a lot of fun designing and problem-solving through all the problems that this project brought up. Even though all the trials and errors when working in Fusion 360 and printing. For example, when printing the prototype the base and box didn’t fit. So there had to be adjustments that had to be made.

During this project, I would say that I learned a lot about how Fusion 360 works and how 3D printing works, and what are the best settings. But I would have to say overall the project was very rewarding and seeing an idea come from paper all the way to a physical design is very cool.

And yea that's how to create your very own french fry train!