Introduction: The Tremulator

This was a project I had been meaning to do for a while after watching a TV show called The Big Life Fix, as well as seeing various devices which do similar things (but often for a rather large price tag). I wanted to make a device that could give the user some idea of what it was like to experience the tremors caused by Parkinson's disease or Essential Tremor. And so the Tremulator was born.

2.2% of the US population suffer from tremors, and they impact every aspect of your interaction with the physical world - eating, drinking, painting, writing. And yet the people who design and make things, from people like you and me to design giants like Apple or Ikea, tend to be at the very good end of hand control and dexterity - it is a kind of important prerequisite for the job! Raising awareness for the need for inclusive design, at all stages of the process, is something that is very important to me.

If anyone is interested in devices which either aim to reduce the impact of tremors, or give people experience of tremors to build empathy, I will include some links at the end.

Supplies

This is very much a non-exhaustive list of things I used in making the device, lots of these items can be substituted for others depending on what you have available. I used scrap wood that I got for free from various people, some football socks I had outgrown etc. If I had a 3D printer available I could have printed quite a few of the parts and they would have fit better, but I don't and it works well enough as it is!

I also really wanted it to be something that is accessible to lots of makers - I would say my total outlay on this project was only a few pounds, and I can reuse most of the things for other projects as well.

  • Wood
  • Football sock
  • Velcro
  • Fabric
  • 2 AA Batteries
  • Battery holder
  • Wires
  • DC motor
  • Hinge clip
  • Fan cap
  • Angle
  • M4 bolts and hex nuts
  • Lots of duct tape!

Step 1: Design

I drew quite a few sketches, and talked to some people who had experience doing similar things. I also drew inspiration from this Twitter post for the concept of the rotator. The main crux of the design was having a rotating part which had a centre of mass away from the centre of rotation to create the vibrations. The rest of the design was working out how to attach this to my body!

Step 2: The Rotator

The most important element of the design was the rotator – the part that makes the hand shake. I explored a variety of options for power and chose a small 6V DC motor because it was lightweight and compact. This was powered by a battery pack of 2 AA batteries, so not the full voltage but I didn't especially want pointy bits of metal swinging around at super high speeds.

I used the cap part of a fan blade to attach this to the motor, as it had a hole the right size to attach to the shaft, and used various metal pieces to provide the weight. A trip to my local hardware shop (shoutout to discount décor) was in order. I then taped it all together - not the most long lasting but hey it works.

Step 3: Body I

In my initial prototypes I attached all of the electrical components to a piece of scrap plywood and duct taped it to my arm – and it worked! The motor is held in place with a hinge clip used by plumbers to hold pipes in place, which was just the right size, and had a hole for a screw in the bottom. The electrical connections were either soldered or held together with (you guessed it) duct tape. I added a paperclip to the end of one wire to make a makeshift switch, in a more developed prototype I would add something a bit less prone to sparking!

Step 4: Body II

I decided to move to a design using a thicker but smaller piece of wood, so I could screw the components down and make them more secure. My (hypothetical) advice is make sure that (hypothetically) your screws aren't too long and won't go into the wooden table underneath (definitely not speaking from experience...) causing irreparable damage.

Step 5: Sleeve

To attach it to my arm, it had to be tight so that the vibrations of the device were transferred to the hand not the body of the device, but it also had to be easy to get on and off. I decided to try and make a sleeve for it – using a football sock. This provided both compression and flexibility and is a hardwearing fabric.

I added a bit of foam underneath where the wood meets the fabric, so that the screws (which poked out of the wood slightly) didn't scratch my arm.

Step 6: Glove and Velcro Strap

I also cut a slit for the thumb so that the vibrations would be positioned over the hand and therefore have greater intensity. I added a Velcro strap to make it even tighter - this was just some velcro sewn on to a strip of fabric. One of these pictures shows the very useful hack of using a bit of ribbon and a safety pin to help you turn a long tube of sewn fabric inside out (plenty of other people on the internet can explain this better than me).

Step 7: The Finished Product (for Now)

I tried doing a range of tasks with the finished device and it worked really well. Using a spoon to move rice, water, soup etc was really difficult. I think the hardest thing to do was write - this video shows me writing a four word sentence, and even that took intense concentration, a tight grip on the pen and it still ended up really wobbly. Compare that to my writing without the glove on the line below.

I don't for a minute think that this brief glimpse means I now understand the world of someone who suffers from tremors every day. But I am definitely more appreciative of the amount of effort all tasks take, and very grateful that when I have had enough I can just turn the device off.

Hopefully one day medicine will come up with a cure (there are currently some treatments available but many people report them not being especially effective. Until then, inclusive design will play a crucial role in allowing people to maintain some of their independence.

Step 8: The Promised Links