Maker Coin - JorgeJ

Summary -

These were the constraints for our MakerCoin. All coins must be made from an initial revolve, resulting in a coin that is 6 cm in diameter and 1.25 cm in thickness. The initial rule of making the coin from a starting revolve had some leeway depending on the design of your project, and my project design required a starting extrusion. The next constraint was that it must not require any support. The next constraint was that it should have no moving parts, but again this rule was bendable if it wasn't too complex. The final constraint was that the coin should slope down near the center of it in some fashion.

Overview And Background -

My initial ideas came from the fact that this project was gear-inspired from the start, so I wanted a mechanical-looking design.

I wanted to include some kind of moving part in my design, so I decided to have rotating wings on either side. Originally, I wanted to have two layers of these moving parts, but due to the size constraints, I decided to keep it to one layer.

Design Choices - 

The first changes in my design were with the wings. I made them using a series of sketches and then a loft.

The way I made the sketches for the loft caused the back edge of the resulting wing to be very straight and sharp. The end of the wing was also very straight and simple. I fixed this with a simple extrude cut.

This was the resulting geometry. 

Other than that  I didn't face any other design changes or difficulties until the very end. 

This was the final Model All I needed to do was split this up into parts so It could be 3d printed and have all its intended functionalities. By far the biggest challenge after I designed and made everything was finding a way to split it up.

The problem I found myself working on the most was splitting up the spinning gear and wing design to split and then fit back together very nicely as the wing was a very complex and smooth shape. 

This is how the wing looked before splitting it up. Printing it just like this would've been a problem as the complex curves being printed in this horizontal direction would've been a problem for the printer so I had to come up with a way to connect them but still keep that original look I was going for.

My idea was to make a small indentation in the shape of the wing into the gear where the wing could slot in a couple millimeters. The first way I went about doing it though didn't work.

I first tried using the Combine feature with the Subtractive option to cut out the shape of the wing directly into the gear. I did this by making a copy of the wing and scaling it up just a bit so the fit wouldn’t be too tight. Then, using the Move Body feature, I moved the copied wing into place and used the Combine feature.

Unfortunately this didn't work as the shape of the wing tapered down from the base out to the tip. This meant that the entrance to put the wing into the slot was smaller than the base because of this taper because the hole was the exact shape of the wing. As you can see in the photo the highlighted orange outline was the actual wing and it was bigger than the hole for it.

So I came up with a different way that would be able to fit the base of the wing even if there was some room left over. 

I made a cut on the wing to just have a flat face tangent to the gear. Then I could just extrude and cut the base of the wing into the gear ensuring the base and the wing could fit into the slot. Again I made a copy of the wing and scaled it up to add some tolerance into the fit and extruded the slightly bigger base into the gear.

Next I just needed to add so rectangular cuts in the middle of the slot and wing allow for a peg to do in and connect them both.

This was the Final design and was perfectly flippable for the other wing on the other side.

The top photo shows the new and split gear and wing on the left, and on the bottom, it shows the old one. I was very happy with how it came out. It still looked very similar to the original. The final thing I did was adding some more rectangular cuts into the main body to allow pegs to connect the bottom and top half of the main body of the coin.

This was the final Design
 

Extra Photos - 

                                                            Assembly of The Coin

                                                                     Section View 

                                                               Real World Look