Payload Attachment Concepts

Overview Securing the payload is important for safety and appearance. Securing the payload is important for safety and appearance. The payload should not come off the platform during platform operation. The payload should not come off the platform during platform operation. The platform should look organized when the attachment device is not in use. The platform should look organized when the attachment device is not in use.

Needs Addressed  SAFETY (1)  Perform required tasks (3)  Economical (5)  Robust (6)  Appealing (8)  Easy to manufacture (11)

Issues  The securing devices must be easily concealed in the platform.  They must therefore be light and small to not overload the platform.  It is desirable to have the mounting holes be multi-functional for multiple mounting devices.

CONCEPTS  Tee nuts These can be secured by a bolt to a slot, meaning they can be moved to any location along the slot.These can be secured by a bolt to a slot, meaning they can be moved to any location along the slot.  Toggle clamps These are a quick and simple way to tightly secure the payload; just turn a lever.These are a quick and simple way to tightly secure the payload; just turn a lever.

Concepts  Tie-Down Straps These are lightweight and easy to use and storeThese are lightweight and easy to use and store  Bungee holes around edge Bungee cords are easy to use, and mounting them in specific holes would add strengthBungee cords are easy to use, and mounting them in specific holes would add strength

Concepts  Platform materials with holes More holes than the previous idea, easier because purchased with holesMore holes than the previous idea, easier because purchased with holes  Platform materials with threaded holes Advantageous to a simple grid because anchors could be applied to the holesAdvantageous to a simple grid because anchors could be applied to the holes

CONCEPTS  Drop-Down Gates Gates would be easily storable, and would fence the whole platformGates would be easily storable, and would fence the whole platform  Side Flaps Flaps would easily expand the surface area of the platform, and be easily storableFlaps would easily expand the surface area of the platform, and be easily storable

Preliminary Analysis  Tee nuts ProsPros  Versatile  Looks impressive ConsCons  Difficult to manufacture  Not economical  Toggle clamps ProsPros  Easy to assemble  Looks impressive ConsCons  Difficult to manufacture  Expensive

Preliminary Analysis  Tie-Down Straps ProsPros  No assembly  Clean in appearance ConsCons  Not as strong as some methods  Expensive  Bungee holes around edge ProsPros  Easy to use  Economical ConsCons  Not a strong hold on payload  Difficult to manufacture

Preliminary Analysis  Drilled holes (grid) ProsPros  No assembly  Economical ConsCons  Not impressive in appearance  Not a strong hold on payload  Drilled and tapped holes ProsPros  Added visual appeal  More secure hold on payload ConsCons  Not easy to use  Not durable

Preliminary Analysis  Drop-Down Gates ProsPros  Impressive in appearance ConsCons  Not easy to manufacture  Not light  Side Flaps ProsPros  Impressive in appearance ConsCons  Not robust  Not much restraining force on load

Final concept Create a Drilled and Tapped Grid Through Pugh charts, we deduced that these two options met more of our criteria with a higher score than any others. The grid without threads was versatile in anchoring the load, and the threads added to our payload- securing options. We looked for bungee cords for this design, and found two options on MSC Direct. One was essentially four cords bundled in the middle (hooks are made of fiberglass and nylon), costing $14.65 per cord, and the other was a rubber bungee cord, 5/16 inches wide with metal S-hooks, costing $4.01 per cord.