Design 1
Design one's frame primarily consists of PVC piping and jointing. the entire hull resembles a rectangular prism except it is missing the front top cross section. The top cross section is absent to reduce drag through the water while also retaining as much rigidity and structural stability as possible.
The absence of the cross section also slightly lowers the total weight of the frame and allows more room for mounting equipment. PVC piping was used because of its structural strength and because it is fairly cheap, easy to manipulate and easy to mount equipment to. PVC piping is significantly cheaper than aluminum kits or acrylic molding.
Majority of the equipment such as the mechanical arm and cameras can be easily attached to the ROV by simply using zip ties or aluminum fasteners which are screwed into place. Before assembling the ROV, holes can easily be drilled into the piping to use as mounting points and can later be sealed.
Design one also has a cross section running through the middle of the frame laterally. The cross section is meant as a mounting point for both vertical and horizontal propulsion systems. Since the design resembles that of a prism, the most stable point to mount any propulsion would be in the middle of the frame. When placed in the middle of the frame, the hydrodynamics across most surfaces become even throughout the entire craft. This allows for smoother turning and handling.
This frame also uses foam pool noodle ballasts for positive buoyancy. Foam pool noodles are easy to find, are cheap and are very easy to cut and mount. If the positive buoyancy is too great, than some of the foam ballast can be jettisoned and adjusted to the overall weight of the craft.
Design one also incorporates small DC RC motors for propulsion through the water. All other designs share this because small RC motors are cheap, easy to find, easy to waterproof and provide ample propulsion for their small size.
Figure 1: Design 1 side view
Figure 2: Design 1 Front View
Figure 3: Design 1 Top View
Figure 4: Design 1 Isometric View
Figure 5: Design 1 Front, Top and Side View
Design 2
Design two's frame is not constructed of PVC plastic tubing, rather it uses plastic parts found in hobby shops and numerous physics build kits. these plastic pieces are strong, rigid and are extremely easy to use and put together. These rods come in numerous different sizes and lengths and are similar to how legos or k'nex fit together. These rods snap together because of the tips on the ends and the holes in the center of each rod. Since the plastic is also strong, put together the rods are able to handle a sizable load. Since the rods also have holes in them, they provide additional points for mounting equipment such as cameras or wires.
The frame is almost literally a cube, since the rods are not exactly as strong as PVC piping, a stable shape or design is required. But, the cube shape also allows for smooth easy handling. Due to the fact that a cube is symmetrical anywhere, the water flow across the surfaces is even. This allows for controlled handling through the water.
Although this frame is expected to carry as much weight and equipment as other designs, not as much ballast is needed for positive buoyancy. The plastic is much lighter and less dense than PVC piping. So, empty film canisters glued shut act as positive buoyancy. The film canisters are located along the top rails to provide stability when ascending or descending depth.
When mounting equipment, zip ties can be used again or plastic fencing/netting can be placed at the bottom of the frame to create a stable platform in which equipment can be strapped to. The mechanical arm can be laid across the bottom of the frame where the netting is located or it can be strapped across the side of the ROV.
Design two again takes advantage of the small DC motors to propel itself through the water. The back area of the frame has two bars running down from the top rear cross section down to the bottom of the frame. The purpose of these two bars is to provide a specific mounting point for the two RC motors. The two bars will sandwich the motor and give a snug stable area for the motors to mount on.
Figure 6: Design 2 Front View
Figure 7: Design 2 Top View
Figure 8: Design 2 Side View
Figure 9: Design 2 Isometric View
Design 3
Design three's frame takes on an interesting shape. The bottom of the frame is a simple rectangle; but, rather than have the sides of a cube the frame splays our wing like projections at a forty five degree angle. With positive buoyancy at the tops of these wings it allows the craft to be extremely stabile and allows much more room at the base of the frame for mounting any and all equipment. However, with the craft being stabile, turning will be difficult and slow.
The wing like projections also have ballast at the top cross section. With the wings splayed at a forty five degree angle more room is allow for equipment. The ballast again will be foam pool noodles because of their cheap price, versatility and ease of use. Because the top of the frame is wider than the base, it offers a steady platform because the ballast is located so far from the base.
The propulsion is also small RC motors. The horizontal propulsion motors are located behind the last vertical section of the wing. With a high and wide ballast, the horizontal propulsion no longer needs to be exactly centered. The vertical propulsion is on the PVC pipe in the middle of the frame. Although the ballast does make the craft more stabile, the vertical propulsion should stay in the middle. If the propulsion is off center than the whole craft may tip.
Design three may be cumbersome in size and appearance both the wide upper frame allows for a steady platform to mount equipment and the mechanical arm. The wing like projections also allows ample room for cameras and such. But, the wide frame also causes more drag which in turn causes the ROV to move slower through the water.
Figure 10: Design 3 Front View
Figure 11: Design 3 Side View
Figure 12: Design 3 Top View
Design 4
Design four is a simple plane design. The entire frame is essentially a submerged barge under the water. The frame is made of PVC again since it it so easy to mount equipment on. However the ballast is completely different. The ballast consists of plastic bottles which can be filled with air and water to control the amount of positive buoyancy. These bottles are placed on the outside edges of the frame to provide stabile lift and to prevent the frame from wobbling or tipping.
Additionally, weights are placed underneath the the craft right next to each other. These weights are PVC pipes that will be filled with BB or lead shots to accurately control the weight of the craft and to bring it as close as possible to neutral buoyancy. These weights are placed underneath the flat base centered and right next to each other.
Small RC motors again provide propulsion. Vertical propulsion is located on the outside of the frame next to the plastic bottles. Horizontal propulsion is located toward the rear of the craft behind everything including ballast.
The middle of the base contains either hard plastic non corrosive metal netting in which the mechanical arm and additional equipment can be laid across.
Figure 13: Design 4 Side View
Figure 14: Design 4 Top view
Figure 15: Design 4 Front View
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