Rainbows at Orange Enterprises: Building a Color Blindness Test Kit

Designers:Janet Saldana and Josh Wu

Advisor: Lauren Spencer, Denise Moody, DeeDee French

Supervising Professor:  Kevin Caves


Orange Enterprises services people in the community with disabilities by giving them jobs and the opportunity to earn money. One of the more difficult jobsColor Test OE 2016 currently involves making color blindness test kits. The high levels of judgement and hand dexterity required severely limit the number of people who can do the job. For this project, we designed three devices to help facilitate in the making of these cards. They serve to increase efficiency and ease of completion while maintaining high standards for product quality. These devices provide a way for many more clients at Orange Enterprises to participate in this job.


Orange Enterprises (OE) is an organization that provides employment opportunities to individuals with disabilities. OE has two offices: Hillsborough and Burlington. They are contracted by outside companies to complete various jobs. Jobs are broken down into steps, and the clients are paid according to the steps that they can satisfactorily complete. One of the assignments involves making a color blindness test kit (Figure 1). Currently, the job is only done at Burlington.

In the first step of assembling the kit, OE workers make snippets of three-yarn strands. The workers wrap yarn around a yarn jig, crimping beads at specified distances. The yarn is then cut to produce small strands with beads at the end. However, the workers often string the jig to different tensions. When the yarn is cut, the strands will often shrink, becoming much shorter than required and unusable.

Color Test OE 2016 Fig 1

Figure 1: Fully assembled card.

The next step involves stringing strands of yarn through holes, straightening, tightening, and taping them down. This step currently requires significant judgement as the yarn must be strung through the correct side of the card, and the yarn needs to be taut and straight. The taping process requires hand dexterity and the use of both hands. There are several other steps. However, these are the rate-limiting steps that seriously reduce the number of workers able to do the job and will be the main focus of this project.

As OE services people with various disabilities, the abilities of clients are very wide ranging. However, this project will be aimed towards three clients at OE: James and Ellen from Hillsborough, and Linda from Burlington. James is a man with spina bifida, and Ellen has experienced traumatic brain injury (TBI). Spina bifida is a condition occurring at birth when the spinal column does not completely close [1]. TBI is an injury involving permanent damage to the brain [2]. James and Ellen are both able to use their hands to pick up things and complete various tasks to a limited degree. They have trouble with smaller objects and also tasks that require hand dexterity. Additionally, they both have a strong preference for one hand over the other. James and Ellen can both walk and stand, although James usually uses a walker. They are able to understand other people clearly and learn tasks. However, it is difficult for them to judge the quality of finished materials, and thus completing certain tasks accurately despite knowing what they are supposed to do.

Linda is a woman with Down syndrome, a condition in which a person is born with an extra copy of chromosome 21, causing a variety of disabilities [3]. Linda currently specializes in the stringing process that makes the yarn snippets with over a decade of experience. She has full use of both her hands and can walk freely. Although she does have higher quality judgement and learning abilities that most of the workers at OE, she still does experience many difficulties from time to time.

Color Test OE 2016 Fig 2

Figure 2: Yarn tensioning jig

Project Goals

The goal of this project is to optimize the process for building a color blindness test kit to reduce physical dexterity and judgement required to a minimum. To reduce the physical requirements of the process, the devices should be designed for one-handed people. The project will focus on revamping the rate-limiting steps: making strands of yarn, stringing through holes, straightening, tightening, and taping them down. The devices need to be easy to use and to teach. Additionally, as clients are paid according to the steps that they can complete, the optimized process should be able to be broken down into steps.

Design and Development

This project includes several devices: a yarn stringing jig, a stand and a spreader. These devices are used to facilitate the efficiency, accuracy and ease of completing the rate-limiting steps in the making of color blindness test kits. The OE workers will first use the yarn jig to produce several strands of yarn. The stand is then used to hold the card and help the workers string the yarn through the card and straighten the strands. Finally, the spreader is used to pull the strands tight and tape them down.

         Yarn Tensioning Jig

The first device, shown in Figure 2, is a yarn stringing jig that facilitates the making of the yarn strands. It allows the user to crimp and cut the yarn at the required lengths, while also regulating tension. The jig can produce 18 snippets at a time.

Color Test OE 2016 Fig 3

Figure 3: Pulley and pole pair

The device works by first tying the end of the yarn to the hook eye on the right. The yarn is then strung through the holes of 3D-printed yarn holders and then wrapped around 3D-printed rotating pulleys nailed to the board. Between the yarn holders and the pulleys at each end are 3D-printed pole pairs (Figure 3). The yarn holders, pole pairs, and pulleys serve to guide the yarn, and increase accuracy of tensioning. After the yarn is strung three times, a 1-kg tension gauge with a rotating dial, attached to a chalk line reel on the left, is pulled towards the right until it reaches the pulley. The yarn is cut and tied to the hook on the gauge.

On the far left, the reel is held in a 3D-printed holder with notches for the reel knob to be placed, locking the length of the reel line place. The reel handle itself has an 3D-printed attachment that allows for easier turning of the handle. The handle is turned until the dial on the gauge reaches the marked region, then the reel knob is placed in the closest notch. This is shown in Figure 4.

Color Test OE 2016 Fig 4

Figure 4: Reel and tension gauge.

Yarn holders are arranged as shown in Figure 5. Crimp bead covers are placed at the marked regions in the figure, directly in the middle of the yarn holders. A specialized crimping tool is used to crimp the beads. To produce the strands of yarn used in subsequent steps, the yarn is cut at the shorter gap between the beads. The entire device is mounted on a ten foot length of 2×6 cut down the middle with hasps attached for portability. The board is stained with gel wood finish.


The second device, shown in Figure 6 below, is a stand that can hold cards. This stand is used to facilitate stringing of the yarn through the holes and straightening the yarn. The stand is essential as it provides a way to hold the card, allowing all further steps to be done with one hand.

Color Test OE 2016 Fig 5

Figure 5: Yarn String Holders

The stand was assembled using several lengths of 2×2 wooden bars. It consists of four columns (5.5 in), held together by two bars in the front and back (7 in) and two shorter raised bars (3.5 in) on the right and left. A sheet of metal is attached on top. Two additional sanded horizontal bars (6.5 in) with neodymium magnets embedded are hinged at the top. With added dycem lining, these magnets allow the stand to grip to the card and hold it stably in place. The dycem lining is painted in order to show where the card needs to be placed. Two knobs are attached on the outside of each of the 6.5 in bars to allow for easy opening and closing. The entire device is stained with gel wood finish.

The user can use one hand or both to strand snippets of yarn through the holes, either from top-down or bottom-up. The lightweight design allows the stand to be easily maneuverable, and is able to be rotated and flipped upside down if needed. Clients can check over the yarn snippets during this step to ensure that the three strands of yarn within each snippet are parallel.


Color Test OE 2016 Fig 6

Figure 6: Stand

The final device is shown in Figure 7. This device is used to pull the strings to a desired tautness before taping them down. Built on a polished and heat-treated polycarbonate base (7.8 x 9 x 1 in), the spreader is a hinged device with parallel bars coming down the center. The bars can slide apart due to a slotted square channel anchored at the top of the base. Two metal rods are attached to the parallel bars on each side and then attached to 3D-printed handles. A 3D-printed guard against pinching is attached near the square channel. Glued below the base is a rubber back to provide grip to the table.

Initially, the bars are set to touch and the hinge open. Once the card is set on the base according to one of three markings, the bars are placed down. Pulling apart on the handles separates the parallel bars in the middle, which catches the beads on the yarn snippets and pulls the snippets taut. The client can then one-handedly tape down the yarn while also being restricted from placing the tape incorrectly, ie. outside the borders of the card and on top of the beads which later need to be cut off.


Color Test OE 2016 Fig 7

Figure 7: Spreader

The three devices were evaluated against the predefined design specifications. Overall, the design had to be simple and intuitive, while effectively producing quality products. The clients needed to be able to learn the steps well and fairly quickly, and the devices were to assist in improving the quality of the products as much as possible. With these goals, workers with limited hand mobility or limited quality judgement skills could be brought onboard this job. Although most clients will be able to use both hands, it was verified in lab that all of the steps could be done with one hand. Product quality tests were done in lab and also at the sites. The clients at the Hillsborough workshop did a great job of learning the process from scratch, having never seen the end product before. Clients at Burlington were taught how to use the devices once. At the next visit, they were able to remember how to use them immediately, requiring minimal further instruction. Clients were able to use the devices from beginning to end in making high quality products, as confirmed by OE supervisors. In a staff survey, a supervisor said that the workers and staff are excited to be able to finally keep the devices on-site, just in time for a new order from the contractor. The speed, ease and precision of completing the steps noticeably increased when using the devices. The clients said that the new way of building the kit was better and fun. One issue is that the yarn tensioning jig requires some lateral mobility due to the length. However, the tensioning jig was designed specifically for Linda as it is her specialty. She is used to standing while working with the old jig, and thus should not have a problem moving around the new jig. Overall, the specifications were met, and the client was very pleased with the devices.

Discussion and Conclusion

In the final analysis, the three devices each made the job of building a color blindness test easier and served to expand the number of clients able to take on the tasks. For those who have already been involved in the job, the designs noticeably improved speed, efficiency, and quality. The devices as a whole fully comply with all of the design constraints and specifications. With the new devices, the limitations that clients at OE have become less relevant. James and Kathy from Hillsborough, who would never have been able to do the job before, were able to both complete the tasks using the devices with minimal direction. Linda from Burlington was able to almost triple the speed at which she made the yarn snippets. Overall, these devices are predicted to fit very well in the work flow at Orange Enterprises.


  1. What is SB? (n.d.). Retrieved February 17, 2016, from http://spinabifidaassociation.org/what-is-sb/
  2. NINDS Traumatic Brain Injury Information Page. National Institute of Neurological Disorders and Stroke. (n.d.). Retrieved March 23, 2016, from http://www.ninds.nih.gov/disorders/tbi/tbi.htm
  3. Down Syndrome. (2016, April 27). Retrieved May 03, 2016, from https://www.nlm.nih.gov/medlineplus/downsyndrome.html


We would like to acknowledge a number of people for their help in completing this project: National Science Foundation grant # CBET 3310005, Kevin Caves, Steve Earp, Greg Bumpass, Jon Goodfellow, Lauren Spencer, Jackie “Deedee” French, Denise Moody, Solow Williams, and all four of our clients at Orange Enterprises.


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