Download File Here: Assembly Drawings, PDF
If you want to build your own water cycle toy, this page will serve as a resource for material lists as well as a complete build guide.
Note: Our team decided to use polycarbonate for the toy enclosure because of its strength and ability to create strong bonds. To build the toy exactly as our team did, you will need access to a laser cutter, 2 axis CNC, and 3D printer. If you don't have access to a CNC or laser cutter, all of these parts can be made of wood, cardboard, or even entirely 3D printed. The table below shows the exact materials our team used to create our toy.
Note: Our team decided to use polycarbonate for the toy enclosure because of its strength and ability to create strong bonds. To build the toy exactly as our team did, you will need access to a laser cutter, 2 axis CNC, and 3D printer. If you don't have access to a CNC or laser cutter, all of these parts can be made of wood, cardboard, or even entirely 3D printed. The table below shows the exact materials our team used to create our toy.
Materials Required
Overview
Our toy consists of a polycarbonate case, acrylic, laser cut parts, and 9 3D printed disks. The outer case consists of the top, bottom, and side panels and is made of 1/8" polycarbonate. In addition to this, there is another layer we call the middle panel or middle layer that is also 1/8" polycarbonate. This panel contains 9 holes and is where the nine disks will sit, which allows them to spin freely while keeping them in place. Our toy also contains many obstacles for the ball such as clouds, a city, and a groundwater maze. All of these parts are made out of 3/8" acrylic which allowed them to be laser cut. Lastly, all of our 9 disks were 3D printed. Our website has a pages called CAD Design Iterations and Latest CAD which contain all our SolidWorks files for our prototypes. This may be useful to you if you have SolidWorks and want to make changes to our design. If you do not have access to Solidworks, all the files used are downloadable on this page in formats required for building.
Instructions
Step 1: The first step is making the enclosure for the toy. This is six pieces in total that surround the toy, plus the middle panel that keeps the disks in place. To start, all of the pieces need to be cut down to size. Our team was able to order the pieces in the exact sizes needed, so this may also be an option. If using polycarbonate, this will require a two axis CNC mill. The CNC uses DXF files with a 1:1 scale.
Step 2: The second step is to add holes in the middle layer as well as the top of the enclosure for the disks. The middle layer contains nine holes for the disks to sit in and the top of the enclosure contains nine holes for the knobs to stick out of. Again this should be done with the 2 axis CNC. Our holes for the middle layer were machined our using a 1/2" end mill and the smaller holes for the top of the enclosure were removed using a 1/8" drill bit. The parts will need to be placed in the CNC and the X,Y, and Z directions will need to be manually zeroed. From here the CNC can mill out the holes automatically. These holes are a very tight fit with the disks, so sanding may be required as post processing.
Download DXF Files Here: Middle Layer
Step 3: The next step is creating the skyline, clouds, maze, and evaporation channel. All of these parts were made with acrylic, so that they could be laser cut. You will need to download the DXF files below. Our team used the laser cutter pictured below. Some portions of the city such as the windows and hospital logo were engraved. When uploading the files to be laser cut the line width for the engraved portions should be set to .007. Everything else should be set to a line width of .001 (hairline). All of the required parts can be cut out of a single piece. For our team, that meant arranging the parts in CorelDRAW.
Download DXF Files Here: Clouds, City and Maze
Step 4: Lastly, the 9 disks should be 3D printed. We used the Formlabs SLA printer because of its smooth surface finish and good material properties. The process begins with the finalized 3D model of the disk in SolidWorks (CAD software). The design is exported as an STL file that is readable for the printer. Again, these files are all available to download. The disks need to be oriented in the software (up to four can be printed at once). The layer height can be set to 0.05 mm for for Formlabs resin.
Once this setup is complete the printing process can begin and the machine can run unattended until completion. Once the disks are complete, they need to be rinsed with isopropyl alcohol (IPA) to remove any uncured resin remaining. The disks can then be cured in a UV-light curing station called a Form Cure shown below to finalize the process. After drying and curing, any support structures present will need to be removed and the surface should be sanded down. The disks can then be painted using spray paint and a clear coat to ensure that they don't chip. Our team also had prototype versions that were printed using FDM printers such as the Lulzbot Mini pictured below that worked as well. For these we used white eSun PLA, which tends to expand after it is printed. For this reason, it will probably be necessary to sand your disks down to ensure they fit and spin smoothly in the holes of the middle layer.
Once this setup is complete the printing process can begin and the machine can run unattended until completion. Once the disks are complete, they need to be rinsed with isopropyl alcohol (IPA) to remove any uncured resin remaining. The disks can then be cured in a UV-light curing station called a Form Cure shown below to finalize the process. After drying and curing, any support structures present will need to be removed and the surface should be sanded down. The disks can then be painted using spray paint and a clear coat to ensure that they don't chip. Our team also had prototype versions that were printed using FDM printers such as the Lulzbot Mini pictured below that worked as well. For these we used white eSun PLA, which tends to expand after it is printed. For this reason, it will probably be necessary to sand your disks down to ensure they fit and spin smoothly in the holes of the middle layer.
Download STL Files Here: Mountain Disk 1, Mountain Disk 2, Mountain Disk 3, Lake Disk 1,Lake Disk 2, Lake Disk 3, River Disk 1, River Disk 2, River Disk 3
Step 5: After this, your parts are ready to be assembled! To adhere the acrylic skyline, clouds, channel, and maze to the polycarbonate middle layer the team used Dichloromethane pictured below. We chose this because it is able to create extremely strong bonds that would not break if the toy was dropped however, epoxy or other glues will work as well. For this, a syringe is helpful to add small amounts at a time. Our team used a sticker, which can be downloaded below, in order to add color to the toy, as well as help align the parts. Once the sticker is aligned, you should line up the sides and bottom piece and add glue to all of the sides. From here, each laser cut piece can be added one by one. It might be helpful to have two people for this part, so that one person can hold down the piece while the other adds glue around the edges.
Download File Here: Art Sticker
Step 6: After your parts are glued together, you can add in the disks and as many balls as you want. When our team was testing the toy, we liked to velcro the top down to make sure we could get back in and make changes if we needed to. When you are sure you don't make anymore changes, you can bond the top piece on using the same method from above.
Note: You can always try and design your own disks in if you want them to look different than the ones given on here. You could make then different colors, shapes, and even change them to teach a different STEAM concept!
