Engineering Proposal: Ergonomic Travel Lap Desk

Introduction

We have specially engineered a lap desk to fill the need for an ergonomic device for commuting students to be able to do homework on the train. Current lap desks are typically designed to benefit those who want to do work in their home environment without having to leave the comfort of their bed. These design aspects include a bulky cushion attached to the bottom of the desk for comfort, a large lap desk size that allows for the user to have both their computer and a mouse on the same surface, and heavy material like wood is used to make the product more appealing for home users. These design aspects are wonderful for use in bed or even on a couch but are the opposite of what would be beneficial to someone who wants to use a lap desk in a public space, like the train. The cushion and the large bulky size make it nearly impossible to fit into a backpack, especially if you are a student who has other items in your bag like books and binders for class. Even if a lap desk is small enough to fit, their usual heavyweight makes traveling with them inefficient and irritating. Not only that but the train moves around quite a bit and typically lap desks just sit in your lap and are not designed to be held still or keep your items still while you are in a moving mode of transportation. Our lap desk is specially designed to solve these issues and has a compact, lightweight, ergonomic design to make it both travel size and efficient for work to be done in places like the train.

The environment-based technical issues of doing homework on a public mode of transportation are what have created the need for our lap desk. Train seats are not very big, and you are confined to your own seat when the train is at full capacity. Not only that but the train does not move consistently steady, so it is very easy for something like a lap desk to slip out of your grip. Therefore, our innovation includes pop-up leg stands so the desk is not resting in your lap, and it includes leg grips that you place under your legs when you sit so just by sitting you can keep the desk safe and secure during use. We have also added a grip-like material to the top of the desk to prevent your work from slipping. Another issue that comes up is that the space available in an average-sized backpack is limited. Therefore, we have included several folding aspects that allow our lap desk to have a compact design. The legs and the leg grips fold into the desk itself and the desk can fold in half to make it even more compact.

This will make a huge difference for commuting students who want to take advantage of long commuting hours to get work done. “Over 15,000 undergraduate and graduate students commute regularly to the City College of New York campus” (Student Life and Services, n.d.). This is just to the City College of New York alone, there is a ton of students commuting which makes a huge market for our product. Not only just students, but a large number of people use the LIRR to commute to New York City for other reasons and they could also make use of our product. “The LIRR topped 150,000 riders per day Oct. 2021” (MTA, 2021).

Innovations That Already Exist

The currently available lap desks that exist fall short on ergonomic design and travel use. There are currently two main lap desk designs, both of which are designed to be used either in a bed or on a couch, and both of which have various designs themselves. The first type is typically made with a large, rounded rectangle slap of wood or plastic and it typically includes bulky cushions on the underside to ensure the comfort of use. The second type is closer to what we have designed where it has collapsible legs so the lap desk can rest on its own legs instead of in the lap of the user. This type however is still bulky and has a large solid piece of either wood or plastic that makes up the main desk component.

The first desk type will be based on the desk LapGear created where the underside is a cushion and the top is a thick plastic (LapGear, n.d). This version is made of plastic which is the lighter version of the type. The other type that is very similar but is made of wood is also made by LapGear (LapGear, n.d). The first type of lap the desk, is faulty for several reasons. The large size of the lap desk makes it too big to fit in a standard backpack so traveling with them is not ideal. The bulky cushion makes it too thick for a backpack and makes it hard to travel with other things in your backpack because it would take up most of the room. Not only are these lap desks large, but the ones made with them are also heavy like the bamboo lap desk made by LapGear (LapGear, n.d). A travel-sized lap desk not only has to be smaller, but it cannot be heavy. The plastic version of this lap desk made my LapGear are lighter; however, they are still very bulky, and the cushion adds to their weight (LapGear, n.d). Another huge downfall to this lap desk is that it rests on your lap. If you are on the train with this type of lap desk, it will move around a lot due to the turbulence caused by the train, so you risk it slipping out of your lap if the train stops abruptly. Not only is this a problem with it resting on your lap, but also a problem with the material the top of the lap desk is made from. Typically, these lap desks are smooth, which also is an issue with train turbulence because your papers could slip of the desk since the desk is very smooth. So, since this lap desk type is bulky and cannot fit in a standard backpack, is too heavy for travel, and does not prevent slipping during train travel, it is an ineffective innovation for the problem we are trying to solve.

For the second lap desk type, we will focus on the lap desk made by Huanuo for the wood version of lap desk two (amazon, n.d). We will also focus on another type made by Huanuo for the plastic version of lap desk two (Huanuo shop, n.d). The second type of lap desk is also faulty for numerous reasons; however, some of these are more effective than the first type of lap desk. These lap desks are typically square and made of either plastic or wood and have legs. The problem however comes from the bulky legs. These legs are usually collapsible and even when they are collapsable, the legs tend to be pretty bulky. Typically if the ones made out of wood are smaller but heavier and the ones made out of plastic are bigger, but lighter. This is a challenge that we have focused on fixing by having a smaller leg design while also maintaining that lightness. However, this type of lap desk has not solved this issue and because of this, it is an ineffective innovation for the problem we are trying to solve.

Technical Description

            The Ergonomic Travel Lap desk (ETL) is made with 3 main components: the frame, the leg grips, and the desk. Each component is a combination of smaller components that include scissor joints, locking joints, and safety latches to keep components in place. The idea behind this design is to make the lap desk as compact as possible for ease of travel. All are made of acrylonitrile butadiene styrene (ABS).

The Frame

            The frame is made up of three sides that have scissor joints which aid in its collapsible design as well as four bars that connect all the sides. A scissor joint is an x-shaped joint that moves exactly like a scissor. The difference here though is instead of one side being a handle to hold like a scissor and the other being a pair of blades, both sides are dull bars that flatten out completely and open at an x shape (Wikimedia, 2021). These scissor joints are what make the frame collapsible. The sides of the lap desk both have a scissor joint so the lap desk can be expanded and collapsed on the sides. The top of the lap desk also has a scissor joint where it also can be expanded and collapsed. The top of the lap desk is where the desk component attaches to. These scissor joints are made of ABS.

The four bars that make up the frame and connect all the scissor joints are made of ABS. These four bars are what hold the leg grips as well as the locking mechanism. The locking mechanism is a thin flat spring plate with a gear at the front end. This locking mechanism is what keeps the scissor joints in place and allows the scissor joints to be adjustable to the height the user wants to set them at. This locking mechanism is made of ABS as well.

Figure 1. The frame of the ergonomic travel lap desk. Figure 2. Fram of ergonomic travel lap desktop view.

Leg Grips

            The leg grips are two thin ABS plates connected by a swinging joint on the two bottom bars of the frame. These leg grips are adjustable and can be pulled out if the user chooses to use them. This component allows the user to keep the lap desk in place while seated by placing their legs on top of the leg grips, which makes the lap desk remain stable.     

Figure 3. Bottom view to show leg grips. Figure 4. Close-up view of the locking mechanism.

The Desk

            The desk component is made of Acrylonitrile Butadiene Styrene (ABS) and is what the user will use to write on when the lap desk is being used. It folds with the aid of hinge joints to make the desk component more compact. The desk sits on the top part of the frame and is held in place by the safety latches located on the top of the frame. In the hinge joints will be aluminum pins to ensure ease of movement for the hinge joints. The desk will fold into a rectangular prism that surrounds the frame when the frame is fully collapsed to ensure a compact travel size.

Figure 5. Expanded view of the desk component attached to the frame. Figure 6. Top view of lap desk with desk on top of the frame. Figure 7. Underneath view of the lap desk.

Process of Innovation

The product will be produced via 3D printing. Being an additive method of production with almost zero waste of material, it reduces the cost of making each piece. Partnering with a third-party 3D printing service that works with ABS plastics, eliminating the need to have in-house printers and printing supplies. Though it is hard to calculate the cost of production given that it would be based on the quote given by the printing service. The cost of ABS is $25 per kg, our goal weight of the ETL is 1 pound which is about 450 grams, 50 grams half a kilogram, half a kilogram of ABS would cost $12.50, leading to the cost of producing 1 ETL being about $12.50 (Flynt, 2018). But to account for the cost of using a printing service and labor costs the cost of the production is raised to a theoretical $20. As for the material choice of ABS plastic, it is an impact-resistant low-cost plastic, easy to machine, and thermoform. Commonly used in 3D printing projects. Making ABS one of the most viable options.

References

Amazon.com: Huanuo lap desk- fits up to 15.6-inch laptop … Amazon. (n.d.). Retrieved April 25, 2022, from https://www.amazon.com/HUANUO-Foldable-Breakfast-Tilting-Adjustable/dp/B082NT5WB1

Bamboo lap desk, Chestnut. LapGear®. (n.d.). Retrieved April 25, 2022, from https://lapdesk.com/collections/lifestyle/products/bamboo-lap-desk-chestnut

Cup holder lap desk, white marble. LapGear®. (n.d.). Retrieved April 25, 2022, from https://lapdesk.com/collections/lifestyle/products/cup-holder-lap-desk-espresso

HNLA6 portable laptop stand with 2 CPU cooling fans. Huanuo shop. (n.d.). Retrieved April 25, 2022, from https://huanuoav.com/products/hnla6-portable-laptop-stand-with-2-cpu-cooling-fans

MTA announces new pandemic-era ridership records set on NYCT subway, LIRR, Metro-North, paratransit and si railway. MTA. (n.d.). Retrieved April 25, 2022, from https://new.mta.info/press-release/mta-announces-new-pandemic-era-ridership-records-set-nyct-subway-lirr-metro-north-0

Flynt, J. (2018, April 5). How much does 3D printing filament cost? 3D Insider. Retrieved April 26, 2022, from https://3dinsider.com/3d-printing-filament-cost/

Student Life and Services. City College of New York – Student Life and Services. (n.d.). Retrieved April 25, 2022, from https://ccny.smartcatalogiq.com/en/2021-2022/Graduate-Bulletin/The-School-of-Education/Student-Life-and-Services

Wikimedia Foundation. (2021, October 6). Scissors mechanism. Wikipedia. Retrieved April 25, 2022, from https://en.wikipedia.org/wiki/Scissors_mechanism

Credits

Samantha Kohn – Main Writer, Main Organizer, Presented Introduction

Mehrab Chowdhury – Creative Designer, Presented Our Product Slides, Sub-Writer

Dayrie Martinez – Main Researcher, Presented “Product materials”

Francisco Medina – Sub-Researcher, Main Presenter, Presented “Products in Market”