Spicy Potato Maker Coin Fidget

Goals & Guidelines

My task for this project was to follow the guidelines provided to make a Maker Coin that represents myself in some way. Some of these rules include making a revolve that creates a 6 cm diameter coin that has a height of 1.25 cm, resembling a gear in some way, sloping downwards towards the center, and using multiple colors while printing or creating moving parts that are still print-in-place.

Overview & Background

In middle school French class I had the nickname Pomme de Terre Épicée (hence the Printables username), or Spicy Potato in English. I wanted to center my Maker Coin design around this because it felt like something truly unique to me. Because I can’t sit still without moving some part of my body, I also wanted to create something that I would want to carry around with me all the time to play with. That’s why I decided to create a coin that would have moving parts. I also wanted to create a simple, clean design that focused more on the moving features than complex patterns.

Design Process

My final coin ended up looking pretty different from my initial paper sketch, but it helped me start somewhere. While I had an idea for what the center would look like, I was less sure about how I would make the outer edge look, so I decided to put something down and make my mind up later. I’m going to break up my journey of creating this into general chunks (almost like chapters in a story) so it is easier to follow.

1: The Beginning (Pretty Basic)

I made a constraint box on a front plane sketch so I could create a revolve for my man coin. I made two different sections to create the first type of movement, where the inner layer will spin, but it will stay contained because of the angle. This is a similar concept to print-in-place telescoping fidgets, and you can click here and here to see some examples of what I did in the past.

After rounding the edge, increasing the angle, and decreasing the width of the outer ring, I revolved the sketch around the vertical line on the origin.

To incorporate the “pomme de terre” (potato) part of the design, I created a potato-shaped spline on the top of the coin, and I used cut through all to make a hole in the middle of the shape.

In order to make the chili spin, I made a rod that went through the middle of the potato-shaped hole using a sketch on the front plane and extruding it mid plane. However, it was not lined up properly, and I realized as I looked at it that it would not work.

The first step for me was to use the right plane instead of the front plane to make my sketch, so the rod took up less space and made it easier for the chili to spin. In order to line it up, I rotated the potato sketch. This also gave me more room to create a deeper hold for the rod, meaning it would be less likely to fall out.

I made the hole that the rod would go into, making it only 0.31 cm so I could also make the rod thinner and less noticeable.

Because the potato has an organic shape, I needed to make an extruded cut in two directions, with different lengths.

I needed to give some space between the rod and the hole it went into, so I made the dimensions of the rod a bit smaller.

2: It’s Getting Spicy! (Adding Details)

To start the highlight of my coin, I made a sketch of the chili on the top plane, using splines for the main part and arcs for the stem.

It looked small, so I scaled it by 1.3, and centered it so it would have space to spin. After that, I extruded it 1.25 cm to be at the same height as the rest of the coin.

I added a sketch on the top surface of the outer ring and put the text I would use (my Printables username/ inspiration for the coin). After that, I cut extrude it 0.07 cm down so it would show up, but it also wouldn’t draw too much attention.

I wanted more control of how much space the text took up, so I used an arc to guide the text.

I wanted to put something else on the ring that fit my theme, so I decided to put Michelin stars. I found a reference picture online, and uploaded it to Solidworks. That allowed me to trace it and get an accurate shape. Just like I did for the text, I made an extruded cut 0.07 cm deep.

One Michelin star looks really sad, so I used a circular pattern in two directions to make five of them (I know the maximum amount possible is three. If you’re confused about my reasoning, search up “Cooking like a chef, I’m a 5 star Michelin”).

I had the basic features completed, so I started to make things look nicer by filleting the potato’s edge 0.15 cm.

3: Tragedy Strikes (Creating a New Plan)

I went to fillet the chili next, but it wasn’t working, likely because of the complexity of the shape. I knew I had to remake it.

My new plan was to use the dome feature to make the chili so it looked round, but that meant the sketch would need to be in the middle of the top and bottom, not on the top plane. I made a plane parallel to the top plane and 0.625 cm above it, right in the middle of my coin.

I used convert entities to transfer the original sketch to my new plane, but I decided to make the stem separately so that the software would not be confused. To make a dome, there needs to be an existing feature, so I made a 0.01 cm extrude.

I used the dome feature to extrude 0.615 cm up and mirrored it over my new plane.

I used convert entities again for my new plane, but this time the sketch only contained the stem. I wanted it to be smaller than the main chili, just like in real life, so I only extruded it 0.5 cm mid plane.

Because of the weird gap that was created due to the rounding of the chili, I moved the stem sketch so it intersected the chili and it overlapped properly. Afterwards, I filleted it to have a smooth look similar to the chili.

To add a little bit more personality and fun to my coin, I created small star shaped cuts and cut them 0.07 cm deep.

4: Living on the Edge

With most of the major problems resolved, I focused on the much-neglected side of my coin. One of the requirements for the project was having a gear-like edge, and the smooth side of my coin was decidedly not gear-like, so I decided to fix it. I started by making a revolve cut using a method I had seen other people do in the past, but it looked too small and I wanted something that fit with the rest of my design.

I made a new plane parallel to the front plane and 3 cm away from it, so it was tangent with the edge of the coin. On it, I copied the same potato shape spline that I used to create space for the spinning chili. However, it was way too big, so I scaled it by 0.5, 0.5 again, and finally 0.7 to get it to the ideal size.

To make a dome the same way I did for the chili, just in the opposite direction, I made an extruded cut 0.01 cm deep. I forgot that the edge was rounded, so it ended up creating a weird shape (on the left) that did not look like a potato. Realizing my error, I increased the cut to 0.05 cm (on the right), which looked much better.

I extruded the dome 0.15 cm. I hoped this would make the edge more texturally interesting.

I used a circular pattern to make 15 evenly-spaced instances of the potato dome, successfully making my coin look more gear-like while still sticking to the theme.

5: Finishing Touches…

Up until this point, I had ignored one of the requirements, which was to have the top slope down towards the center. I knew that the star cuts would look weird if I cut the top of the coin down, so I moved them to the bottom of the feature tree, where I could temporarily pretend they didn’t exist.

I hid the chili and deleted the fillet on the potato edge so it would be easier to cut.

I made a sketch on the front plane and used the cut revolve feature.

I brought back the fillet and the chili. To make the design look better, I increased the fillet on the edge from 0.15 cm to 0.25 cm. I also increased the depth from 0.3 cm to 0.5 cm.

After I brought back the stars (on the left), they were barely visible, so I increased the depth of the cuts from 0.07 cm to 0.15 cm (on the right).

To make the potatoes on the edge more smooth, I filleted the extruded cut 0.6 cm, and I then filleted the dome 0.1 cm. On the left is a picture of how it looked while I was designing, but the right shows a prediction of how it would actually come out.

Unfortunately, I couldn’t circular pattern a fillet on top of other features, so I had to manually fillet the other potatoes, but it ended up looking great.

I thought that I was done, but I still hadn’t seen what the printed version looked like.

6. The End (Creating v2)

There were three main problems with my v1 Maker Coin. I will go over each one individually, along with how I fixed it.

Stars

While my SolidWorks model looks very detailed, the nozzle of the printer was too thick to create such fine details, so I was left with weird dots.

To fix this, I scaled the original sketches by 1.5, making them larger and more noticeable.

I wanted to guarantee that they would show up, so I also increased the cut depth from 0.15 cm to 0.3 cm.

Chili Movement

When designing the model, I didn’t realize that I had left a really small gap between the chili rod and the rest of the coin, so they ended up fusing when printing.

Looking at the original model with a cross section (the top picture), it was clear that I needed to increase the spacing between the parts. I started by increasing the diameter of the cut extrude circle from 0.31 cm to 0.42 cm (the middle picture). Next, I decreased the length of the boss extrude so there was a 0.06 cm gap between the two parts in all directions (the bottom picture), unlike the original 0.01 cm gap.

Font

Because the font I chose was a bit thin, I decided I would use different fonts when reprinting my coin. 

I ended up choosing two different fonts so I could see which one would come out better.

This is how they ended up coming out! I really like how they look, and I included the file for the first text version.