Transportable Classroom Desk Extender

Kim Harrison

Summary:

The desk extender is a solution to the problem many students encounter everyday; that of not having enough desk space in the classroom. Multitasking is difficult enough, and then add to it that the surface you are working on is barely the size of a sheet of paper. The goal of the project is to at least double the surface area of the existing desk while being easy to use and transport for any student. It must hold at least 20 lbf, have minimal vibration and static displacement while in use, take less than 30 seconds to attach and detach, and compact down to a reasonable size for a backpack.
Several concepts were considered based around using a strong, clear plastic sheet for the surface area. Some products exist on the market geared more toward the business traveler needing a portable desk, but not anything portable to improve existing desks. Once concept considered makes use of a simple u-channel to hold the extender in place and an offset hinge for easy folding. Another concept considered has two separate sheets that slide together with a tongue and groove joint.
The final design takes elements from multiple concepts in order to fulfill the requirements. It consists of two 11” by 12” by 0.25” polycarbonate sheets attached together by lid supports, one each on the front and back. One end of the lid support is fastened to the bottom of the extension piece with screws while the other one is fastened to a 0.75” thick strip of wood on the desk sheet. Wood supports are firmly glued on the bottom left and right edges of the desk sheet to level and balance the load. A drawer slide is fastened to the bottom of the desk sheet in the center. It extends to add extra support. A separate spring clamp holds the extender in place, able to attach either on the front end of the desk or the side. For transporting, the drawer slide slides back in and the lid supports unlock and fold down so that the writing surfaces are on the outside.
The final prototype works well. The design is very sturdy, easily holding a large textbook. The clear plastic is aesthetically pleasing. Originally chosen with the idea of using window decals on the bottom to personalize it, it has been discovered that writing on the plastic with wet erase markers also works well. The final size of the product is somewhat larger than earlier decisions. The surface area is more than doubled, but the weight and bulk have also increased somewhat.