System Constraints & Tilt Function
We wanted to incorporate a permanent tilt for our new system for both comfort and visibility. We decided that a permanent wilt was necessary since we were so constrained by factors such as the size of the boat and location of the crank. If it were possible to constantly change the tilt of the seat there was too large of a risk of hitting the side of the boat, the traveler, or having the crank system be out of reach. To find the constraints of the boat itself we took measurements of the actual boat to compare to a CAD drawing of a SONAR vessel we received from Shumway, shown below:
Once this drawing was received and dimensions were gathered from the actual boat we were able to scale this drawing and ultimately create a 3-dimensional layout of the boat, shown below:
Now with a layout of the boat we were able to figure out the “box” by which we were constrained. In other words were able to create models and compare them to the boat and ensure contact was not made by any of the components.
We started to lay out the seat first since it was the driving component and dictated where all of the other components would be constrained and attached. To create a permanent tilt in the system we decided to lift the front of the system while maintaining the same level for the rear. We made a 10 degree tilt because with the natural tilt of the seat the user would be reclined roughly 20 to 25 degrees depending on the specifications of the seat. We decided that was the most comfortable position through trial and error. Below is the initial sketch we made to layout the passenger interface incorporating tilt:
Once a general concept was selected we began to lay out the seat support system. For simplicity’s sake we went with a similar design to the original system with a main support beam with cross beam at the back for side support. We wanted to use commercially available beams sizes so we selected 2” x 1” rectangular tubing with thickness of .250” for better weld quality. Below is a schematic of the selected layout:
Once the support was established we were able to focus on where the rest of the system would line up such as the track platform and crank. Below is the overall layout showing constraints: