Toy Diver Manufacturing Report

1. Concepts

Final Toy Concept

• Pressing the diver down will compress a spring.
• Upon releasing the diver, the spring will unload and force the diver upward into the air.
• The motion of the diver’s fall will vary depending on how her body is hinged.
• Physical Principle: Potential Energy and Gravity.

Initial Toy Concept

The preliminary concept can be found here.

2. CAD Drawing

• Many manufacturing processes require CAD models, or some other type of model
• A CAD model needs to be created for every part of the toy
  • The first step of modelling should really be deciding dimensions. There may be many ways to make this decision, but try to keep in mind the limits of manufacturing processes and costs.
  • The CAD Model of the diver body was created in a unique way. Because the diver is a free-hand drawing that cannot be broken down into simple shapes, an image of the diver was uploaded onto SolidWorks (the program used to model this toy). Then, using the spline tool and trying to follow the image methodically, the diver was drawn and then extruded
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  • The CAD models of the rest of the parts followed a much simpler modelling process because they could be modelled using shapes such a circles, and cylinders with extrusions and extruded cuts.
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  • As can be seen, the models are slightly different from the original toy concept. The reason for this is, while everything works on paper, since the CAD Models have to be used for actual manufacturing methods, these models have to be accurate and have to actually work. Some parts of the toy were completely eliminated, such as the suction cup, because they could not realistically be made and it appeared the toy would work fine without it. Some other modifications include choosing to use five springs along the outline of the base and guiding system instead of the one spring in the center of the original design. Initially, the change was made to five springs without adding the guide system in the center. However, had this been made, the toy would have twisted. The final change that was made was creating the diver bottom. The whole idea of the toy was the see the diver jump off the spring board, but for a while, there seemed to be no way for her to detach from the toy itself. The diver bottom piece simply sits on top of the cap so that the acceleration of the cap upwards pushes it off, along with the diver which is attached to it.
  • Note: The diver cap is actually modeled incorrectly, there should be a cylinder extruding from the bottom face of the top circle. This mishap led to some more on the spot creativity from the team to make the guiding system actually work.

1. Manufacturing

• Materials

Acrylic sheets, metal pins and springs.

• Processes: two main manufacturing processes were used in making this toy model: 3D printing and laser cutting

  3D Printing (AKA FDM Printing)

• FDM stands for fused deposition modeling and is an additive manufacturing process in which two different types of materials are layered in order to create a model. The materials are the modeling material itself, and a water soluble material that is used to create supports. To manufacture the toy, an FDM 3000 printer was used
• .
• Manufacturing using an FDM printer requires some sort of model, in this case a .stl file which can be saved through the SolidWorks models that were created. It is important to note that .stl files do not have dimensions, so when sending in the part to be manufactured, make sure to send dimensions in as well.
• We were not aware that dimensions had to be sent in along with the .stl file, so the parts that were 3D printed, the diver cap and base, wound up being about twice as big as intended, leading to some issues with assembly which will be discussed later.
• Click to see how 3D printers work!

Laser Cutting

• The CO2 laser cutter in the art department digital print lab was used to cut the figure of the diver and the holes where the pins would be placed.
• The cutter works by using a laser to essentially melt away the specified lines. This is safely done by a steady supply of nitrogen.
• For this laser cutter, the outline of the figure needed to be a vector graphic with a line weight of 0.001 inches. For this purpose Adobe Illustrator was used and the drawing was saved as a .eps file in Illustrator.
• The laser cutter can also be used to engrave materials. To engrave, the outline of drawings must be a raster graphic with a line weight of 0.05 or greater.
• The drawings were printed using the CorelDRAW program.

1. Assembly



Body Assembly

The first step in assembling the body of the diver is to glue together appropriate sections. This involves attaching the two body pieces and the two lower arm pieces with super glue. After sticking the pieces together, the glue allows for virtually no adjustment time. With this in mind, we recommend developing some form of a guidance system before super gluing plastic pieces together. To assemble the Diver, we used the pin holes in each part as a reference to help align the pieces. Next, we attach the Diver's limbs to her body using spring pins with a diameter of 3/32nds and a length of 7/16ths. Spring pins resemble a hollow tube with a small section removed from its diameter. This allows the pin to be compressed as it is inserted into a hole and expand back once it is placed to ensure a tight fit. Unfortunately, the pins did not hold the Diver's limbs on to her body tight enough to keep them from falling off upon impact. To compensate for this failure, we inserted a piece of a paper clip into the center of each pin and bent its ends along the surface of the Diver's body. This adjustment successfully secures the Diver's joints while leaving her free to pivot about the pins.

Base Assembly

Assembling the lower portion of the toy involves attaching the base piece to the cap with five springs. The springs we purchased have a diameter of 7/32nds and are approximately .75 inches long. Both the cap and the base have five evenly-spaced raised cylinders on their flat parameter. The springs fit snuggly on the ends of these cylinders and keep the base and cap attached with no further assistance. One of two problems we encountered while working with springs is that springs need a guidance system to ensure that they compress properly. Otherwise, the spring may twist or bend unexpectedly when a force is applied to it. Taking this into consideration, we designed a cylindrical guidance system into the base and cap before we machined our parts. However, this method only fixes unexpected bending, not twisting. Either designing a cross-shaped guidance system or placing each spring inside its own cylinder could possibly have fixed both unwanted motions. A second problem that we encountered while working with springs was finding springs of an appropriate size and spring constant to perform the job that we expected. The springs that we purchased require too high of a compression force and cannot be used in a kid's toy.