Johnson Scorpion Fishing Reel
Eric Metcalf, Sean McKie, Brenden McGregor
This is the Scorpion Fishing Reel made by Johnson.
Replacement fishing reel for loosening/tightening fishing line. This is accomplished by human power as a crank (gear) which through a series of conversions spins and translates the reel to allow fishing line to be released or tightened.
Johnson has a wide variety of fishing reels, this being one of the lower price/quality ($7).
1. Durability and reliability - people who purchase this product do not want the product to be unable to perform its intended purpose or to altogether fail.
2. Aesthetics – purchasers are going to be more likely to buy the product if it is more attractive.
3. Ease of use – the reel needs to be simple and easy to use, shouldn’t require large amounts of time to assemble to the rod or to change lines.
4. The new reel must be able to fit on the most fishing pools
1. Must have reel large enough to fit fishing lines (in)
2. Steps to attach to rod first time (# of steps)
3. Time to attach to rod first time (s)
4. Fatigue life (# cycles until failure)
5. Color availability (# of colors)
6. Steps to change line (# of steps)
7. Time to change line (s)
8. Ability to fit rods (% of modern rod sizes fit)
The table belows lists the Bill of Materials for the Scorpion Fishing Reel:
|Part #||Part Name||Category||Function||Material||Picture|
|1||Pick up or Bail||Support Element||Locking Mechanism for Line (if over line, line is locked into place, if behind, in position for casting)||Metal|
|2||Spindle||Output||Holds wound line, or when turning reel handle, will spin to retract line.||Plastic|
|3||Drag Adjustment Knobs||Support Element||Adjusts tightness of the line. Allows line to “play out” when line is pulled.||Plastic (Exterior)
|4||Bail Spring||Support Elements||Applies force against the Bail when engaged.||Metal/Plastic|
|5||Bail Lever||Motion Conversion Element||Unlocks spindle from gearbox.||Metal|
|6||Plastic Casings||Structural||To add a shine to the appearance of the reel.||Plastic|
|7||Spindle Housing||Structural/ Motion Conversion Element||Protects drive shaft and spins the bail.||Plastic|
|8||Power wheel/gear||Transmission||Transfers power from handle to drive shaft and scotch yoke.||Metal|
|9||Handle||Input||Applies external force to power wheel.||Plastic|
|10||Yoke Shaft||Support Element||Moves spindle up and down.||Metal|
|11||Clutch||Transmission||Stops spindle from rotating in on direction when engaged.||Metal|
|12||Drive Shaft||Motion Conversion/Support Element||Transfers energy from power wheel to spin spindle.||Metal|
|13||Scotch Yoke||Transmission||Converts angular energy from power wheel to move the spindle linearly.||Metal|
|14||Screws||Structural||Holds Parts Together||Metal|
|15||Mechanism Casing||Structural||Outer shell, protects mechanisms, attaches reel to rod.||Plastic|
|1||What Decisions were made in the design of this component/module?||When the wheel was made, the gear ratios, number of teeth, teeth angles and spacing between gears were specified. The type of material was selected in order to maximize performance under normal operating stresses with minimal cost.|
|2||What are the critical features and dimensions?||The critical features are the spacing between the gears so that each connection remains in contact at all times. The number of teeth also had to be specified to match the teeth of the other gears the wheel comes in contact with.|
|3||What kind of loading do we expect to be on the component?||Loading will be applied in the tangential and normal directions from resistances of the gears the wheel comes in contact with.|
|4||What measures can we use to evaluate performance?||Performance can be evaluated by connecting the wheel to matching gears and apply an opposing force while the power wheel is turned by the handle. The stress in the teeth can then be determined and the safety factor computed.|
|1||What Decisions were made in the design of this component/module?||When creating the shaft, dimensions on the length of the shaft, diameter of the shaft, length of the groove, depth of the groove, and the size of the scotch yoke connector had to be determined. Another decision was on the type of material. The company needed a material that will withstand forces applied by the user and also corrosion resistance to the saltwater in case of the shell being penetrated.|
|2||What are the critical features and dimensions?||The critical dimension is the groove for which the scotch yoke moves. The critical feature is that this whole operation of the reel is very smooth and requires little force to begin movement.|
|3||What kind of loading do we expect to be on the component?||The shaft has axial torques coming from movement of the fishing line, and shear on the screw from the same source.|
|4||What measures can we use to evaluate performance?||For destructive testing, a hardness test could be done along with a tensile test until fracture. For nondestructive, test for surface roughness using Ultrasonic.|
|1||What Decisions were made in the design of this component/module?||When the yoke wheel was made, the diameter, number of teeth, diameter of the yoke notch and length of the yoke notch needed to be specified. The material was also selected to maximize performance under stress with minimal cost.|
|2||What are the critical features and dimensions?||The critical features are the diameter of the wheel, number of teeth, and the diameter and length of the yoke notch.|
|3||What kind of loading do we expect to be on the component?||There will be loading in the tangential and normal directions on the teeth, and loading in the shear direction in the yoke notch.|
|4||What measures can we use to evaluate performance?||Performance can be evaluated by spinning the wheel with a resistance applied to the teeth to determine their stresses. The factor of safety for the yoke notch can be determined through a static analysis.|