For our project, we were tasked with designing, modeling, and building a street hockey sled for a child with spina bifida. Our goal was to create this street hockey sled that would mimic an ice hockey sled.
The child we are building this for loves to play hockey, and because of his disability, he is forced to play on a hockey sled. The closest hockey rink is in Nashville, and he is wanting a street hockey sled that he would be able to use and practice on at his house.
We chose to mostly go with the third concept presented. At first we wanted a wheelie bar or wheel placed in the back, but for our final CAD design we just moved the back wheels further back so the chance of tipping back is minimal and the center of gravity is pushed more forward than the wheels.
Our final CAD model shown below is using 1 inch and 0.75 inch square pipe tubing. The 0.75 inch square tubing telescopes into the 1 inch to make the sled adjustable and able to be used in the future; there will be holes drilled and a pin placed inside to lock the adjustability in place. For our material, we are using 6060-T6 aluminum for weldability, weight reduction in comparison to steel, and corrosion resistance for being used outside. For our seat, we are planning to use a classic bucket seat that is used and meant for ice hockey sleds and it has padding along with straps to go over the thighs. The back two wheels will be fixed to only be able to move forward and back, while the front wheel is a swivel wheel for use of turning when in motion. The front portion of the sled will also have a fabric hammock portion to hold the feet in place from touching the ground, and a strap to keep the feet in place and to prevent crossing over.
For our first analysis, we decided to look at the factor of safety for the material we are using. We are using a 1 inch 6060-T6 aluminum pipe with a thickness of 0.08 inches. For use of this hockey sled, the weight we assumed our child to be is about 100 pounds and we used the pipe as the cross sectional area. The factor of safety came to be 86.40, which is very safe for use.