fun and adaptable pie shooting catapult!

Transcription

1 fun and adaptable pie shooting catapult! (made with 3D printing) a project by Maya & Noah

2 the MyPie Catapult project: The MyPie Catapult is designed by Maya and Noah. Maya is the brains behind the design. She loves eating pies, being creative, and is really good at drawing! Maya saw a small wooden catapult for sale at the store. She wanted to buy it, but decided that she could design a better one herself. She designed and drew the MyPie Catapult. Maya recruited her uncle Noah to help with the project. He likes building things and is really good at 3D printing! Noah turned Maya s drawings into 3D printable parts, and made them on his 3D printers. Follow these step by step instructions and build your own pie shooting catapult 1/11

3 making 3D printable parts: Noah used SolidWorks to turn Maya s drawings into 3D printable parts. The first step was to measure the wood dowels and screws used for the project. Using digital calipers, Maya measured the components and added these dimensions to her sketches. She added a little extra space to the holes to allow the wood dowels to easily fit inside. Using SolidWorks, the parts were first drawn as 2-dimensional sketches, and then extruded into 3-dimensional shapes. The dimensions were added to the 3-dimensional shapes to make sure that they would fit correctly. Noah wanted to make sure the parts would be easy to 3D print, so he made a flat base on each piece and used simple shapes that are well suited to 3D printing. 2/11

4 hardware & supplies: To build your MyPie Catapult you will need wood dowels and small screws. You can find both from your local hardware store. The wood dowels need to be 1/4 inch in diameter. The dowels we found cost $1 each, and we needed to buy 2x48 inch long dowels to build the catapult. The screws needed for the project are called #2x3/8 Inch Pan-Head Phillips. The screws cost $3 per pack, and we used 42 screws to build each catapult. cutting the wood dowels: To cut the dowels you will need a sharp razor blade or a small hobby saw. We chose to use a razor blade for our project. Always remember to use the correct safety precautions when cutting the dowels. Adult assistance is best for this step. To build the catapult you will need to measure, mark, and cut these lengths: 1 x 30 cm. 2 x 25cm. 2 x 20cm. 6 x 15cm. 1 x 7cm. Mark the dowel at the correct lengths using a measuring tape and pencil. Lay the dowel flat on the table, and carefully roll the razor blade around the marking to create a score line around the dowel. Carefully bend the dowel so that it will snap at the score line. Don t worry if it leaves a jagged edge because they will be hidden inside the 3D printed parts. You can use a piece of sandpaper to smooth any rough or sharp edges. page 3 of 11

5 3D printing the parts: If you choose to 3D print your own parts you can download the printable models online (search for MyPie Catapult). We printed all of our components on a Tinkerine DittoPro 3D printer. We used a dense infill setting to make the parts strong. The 200 micron resolution setting works well for the parts because they do not have any fine details. To build the catapult you will need to print the following parts: 1 x arm bracket 1 x basket 1 x elastic anchor 1 x elastic bracket 1 x latch a 1 x latch b 1 x pulley 2 x center 4 x wheel brackets 4 x wheel 6 x clamp 6 x corner 6 x T fruit pie (as many as you want!) 3D printing all of the parts took us around 15 hours. We separated the printing into three sections. First we tiled and printed the 4 wheels. Next we tiled and printed all of the connectors and remaining components including the basket. Finally we printed the fruit pies. We printed the pies one at a time so that we could change the colors between each print. page 4 of 11

6 3D printed parts: basket (x1) corner (x 6) arm bracket (x1) latch-b (x1) pulley (x1) wheel brackets (x4) center (x 2) clamp (x 6) elastic bracket (x 1) latch-a (x 1) elastic anchor (x 1) T (x 6) note: The 3D printed Wheels and Fruit Pie s are not shown in this picture. if you are building a ready to assembly kit, the wheels are printed in black and the pies are printed in pink, blue, and purple. page 5 of 11

7 assembly: 1.) build the left and right frames slide the center piece to the middle of the 25 cm. dowel slide a wheel bracket on either side of the center piece slide a corner piece on either end of the dowel next to the wheel bracket make sure all of the parts are facing the correct direction look closely at the screw holes in the picture does yours look the same? screw the wheels to the wheel brackets don t tighten the screws too much or the wheels won t turn repeat the steps to create a mirrored assembly for the other side of the catapult 2.) build the back frame slide the elastic anchor and latch-b to the center of an 15cm. dowel slide a clamp on either side of the latch-b and anchor the clamps should loosly hold the latch and anchor in place so that they can swivel on the dowel tighten a screw in each clamp to hold them in place page 6 of 11

8 3.) build the middle frame slide the pulley to the center of a 15cm. dowel slide a clamp on either side of the pulley the clamps should be loosely hold the lpulley in place so that they can spin on the dowel tighten a screw in each clamp to hold them in place 4.) build the front frame slide two T s on an 15cm. dowel equally space the T s to eather side 5.) assemble the frames to make the lower chassis slide the front and middle and back frames into the side frames page 7of 11

9 6.) build the uprights slide a T to the center of an 15cm. dowel repeat the process to make a second mirored piece 7.) build the cross frame slide the arm bracket to the center of the 7cm dowel. slide a clamp on either side of the arm bracket the clamps should loosely hold the arm bracket in place so that it can swivel freely on the dowel tighten a screw in each clamp to hold them in place 8.) connect the cross and uprights connect the cross frame between the two uprights 9.) build the top frame (same as front frame) slide T s on a 15cm. dowel equally space the T s to each side 10.) assemble the upper chassis slide the 20 cm dowels into the centres (the uprights) add corner connectors to the top of both vertical dowels connect the vertical dowels with the top frame connect the top frame to the front frame with the cross and uprights page 8 of 11

10 11.) assemble the catapult arm slide latch-a and the basket to the 30cm dowel slide the dowel through the arm bracket place the elastic bracket on the end of the dowel adjust the positioning of the dowel and latch-a so it can swing freely and both latches can hook together 12.) secure eveything with screws make adjustments to the connectors and dowels so that the catapult arm can swing freely and the frame is square make sure the latches can hook together add screws to each connector to secure everything in place 13.) pad the top frame wrap a small piece of foam padding around the top frame use zip ties to secure the padding in place page 9 of 11

11 13.) (continued) if you choose to cut your own padding, a piece of recycled packaging or bubble wrap works great 14.) add the elastic loop the elastic through each hook and over the pulley 15.) add the trigger rope loop a string through the latch-b tie a loop at the end of the string so it s easy to pull and fire the catapult page 10 of 11

12 That s it! You re ready to shoot pies to the skies! 11