Reverse Engineering: Automobile Swivel Tray

Box/DirectionsThe automobile swivel tray came disassembled in the box. We had hoped that the tray would come assembled so we could take it apart. Our solution: put the tray together and take it apart again. We avoided the directions page and decided to just go for it. It was very simple to put together, but the directions seemed very helpful in case we ran into a problem. The box had a picture of the tray in use in a car. It stated, “Fits most car cupholders”. This ended up becoming a main issue once we actually put it to the test.

Components

Plate Arm

Half elbow joint with screw (x2) Joint screw (x2)

Half elbow joint without screw Base

AssemblyPutting the actual product together was very easy. There were only two screws and the rest was either a snug fit that required just a bit of elbow grease to make it fit. There were only 8 pieces so assembly was a breeze.

Connect the upper joints Attach arm to the plate

Connect lower joint to the base Connect arm to the base

Assembly completed Tray is freestanding

Testing in the CarHere’s where our suspicions were confirmed. The tray’s base was too small to fit snugly into the cup holder. There is no standard car cup holder size and unfortunately it didn’t fit into Josh’s car. There was no adjustability with regard to the cupholder size. Even if it did fit, we realized that it would get into the way a lot and it could distract the driver. Any sharp turn or aggressive brake would cause the contents of the tray to most likely spill. The design was not ideal and it was quite flimsy and definitely not safe.

Base is far too small for the cup holder

Joints are hard to adjust

Tray barely stands with weight Unstable and easily tipped over

Taking it ApartFor this part of the reverse engineering process, we took the tray apart basically the same way we put it together. We took measurements of all the pieces and weighed all of the components as well. We also took off the non stick rubber on the top of the plate and the rubbery grip on the base.

Measuring Each Component

Bill of Materials

Component Quantity Material Finish Cost Manufacturer Dimensions Function Comments

Plate 1 ABS Plastic

None $ 0.40 Alibaba.com Diameter 23cmEdge 2.5 cm Thickness 0.2cm

-Surface to hold food

-Would probably be a square plate in our design (rather than a circle)

Half elbow joint (with screw)

2 ABS Plastic

and Sheet Metal

None $0.25 Alibaba.com Diameter 2.5cmHeight 4.8cmScrew cap diameter 0.3cmScrew cap length 0.8cm

-Enable plate movement-Screw to hold other joint

-The joint made moving the plate complicated

Joint screw 2 ABS Plastic

and Sheet Metal

None $0.12 Alibaba.com Screw height 1.9cmScrew diameter 0.3cmBase diameter 1.8cmBase height 0.8cm

-Screw in to hold two joints together

Arm 1 ABS Plastic

Chalky $0.05 Alibaba.com Height 16.6cmDiameter 2.0cmThickness 0.2cm

-Holds plate

Rubber Grip Surface

1 Rubber Polymer

None $ 0.09 Diameter 15.8cmThickness 0.1cm

-No slip grip-Keeps items on plate

-Great feature-Incorporate in our design

Half elbow joint (without screw-cap)

2 ABS Plastic

None $0.05 Alibaba.com Diameter 2.5cmHeight 4.8cmThickness 0.2cm

-Enable plate movement-Opening for screw

Rubber Base Grip

1 Rubber Polymer

None $0.13 Alibaba.com Diameter 6.5cmHeight 5.7cmThickness 0.25cm

-No slip grip-Keeps the base inside cupholder

Base 1 ABS Plastic

None $0.12 Alibaba.com Diameter 6.3cmHeight 7.6 cmThickness 0.3cm

-Fits into the cupholder in cars

Total # of Components: 11 Cost of Materials: $1.63

ConclusionWe decided to reverse engineer the automobile swivel tray to see how the product fit

into a cupholder and how the swivel system worked. The tray came unassembled in the box initially. We put it together and noticed that the swivel arm fit into the elbow joints freely. The product fell apart easily and it was difficult to adjust. We put it to the test and placed it in a car cupholder. The sticky bottom was too small for the cupholder, causing to fall from the slightest imbalance. The sticky grip on the tray was good because it prevented slipping and if there was a spill, the ABS plastic barrier could contain the spill. The ABS plastic was very cheap, but also very strong. We decided as a team that we would not implement the swivel technology in our movie theater tray because it was inefficient and ineffective. In order to adjust the product, two screws had to be taken out and the tray had to be moved, which was quite the hassle. The fact that it fell apart and was an irregular shape were the main reasons that we disliked the product. From this reverse engineering, we decided that we are not going to use the same swivel technology that the automobile swivel tray has. The sticky tray surface and strong plastic are the two components of our product that we liked the most.