D4E1 - DIY - Assistive Technology: Adjustable Wheelchair Tray

Kjell has a congenital disability: dyskinetic quadriparesis and is unable to eat by himself. He needs the help of a monitor, an occupational therapist, who feeds him. This comes with two problems:

1) The occupational therapist stands behind the wheelchair to give Kjell food. This in order to support his head during dinner. However, Kjell's wheelchair does not always fit under a table, so the occupational therapist has to stretch very far to reach the food. This is difficult for them.

2) Kjell likes to go on a trip. However, there it is not always easy to find a table, so the problem above is even greater.

Together with Kjell and his occupational therapist, we (2 students product design and 2 students occupational therapy) wanted to make a tray that is adaptable to the needs of each monitor, very compact to transport, fits on different wheelchairs and of course suitable to carry Kjell his food.

1. Parts

- 2x clamp with flexible tube

- 2x threaded rod

- 2x nut

- 2x rotary knob

- 1x tray

2. Materials

- 2x Jansjö desk lamp (IKEA)

- 1x threaded rod M8x110mm

- 2x nut M8

- ABS sheet (2 or 3mm thick)

3. Tools

- Nippers

- Drill

- Hacksaw

- Flat screw driver

- Glue (we used an industrial instant glue)

- 3D printer (possible without it)

- Laser cutter

1. Cut the wire between the clamp and the switch as shown in the first image.

2. Unscrew the screw in the clamp as shown in the second image. That way we will soon be able to easily remove the wire.

3. Saw the lamp at about 1.5 cm with the hacksaw. Use the third image as a reference.

4. After the lamp has been cut off, you should be able to pull out the wire easily.

5. At the top of the lamp you should now see an opening. The threaded rod will soon have to come there. To do this we have to drill the opening according to the diameter of the threaded rod. In our case, this will be 8 mm. If you choose a threaded rod with a larger or smaller diameter you also need to drill a hole with a different diameter.

6. Repeat this process with the second desk lamp.

1. Saw 2 pieces of the threaded rod, each about 2,2 cm long.

2. The 2 pieces should fit quite tight in the 2 holes of 8 mm that we drilled earlier.

1. Glue the 2 threaded rods each in one of the holes that we have drilled out. We use an industrial instant glue. If the hole we drilled earlier is a little bit too big, you can use some hot glue to fixate the threaded rod before you use the instant glue

1. To mount the platform on the flexible arms, we use 2 rotary knobs where the nuts fit. We decided to 3D print it. If you do not have a 3D printer yourself, you can always have your parts made via this site. You can also choose to work with a butterfly nut.

2. When you have the knobs, you only need to glue the nuts into them.

You can find our files for the rotary knobs below.

1. Our tray is made out of ABS that we have laser cutted. If your sheet of ABS has a thickness of 3 mm, 1 plateau is sufficient. When you have a thickness of 2 mm you will have to put 2 on top of each other. You can change our design according to the bowl and the cup you're using.

You can find our files below.

After following these steps you end up with 5 parts. Two clamps with a flexible arm, two knobs and the tray. In the video above you can see how the short installation works.