Steering Wheel Grips

Introduction

For this project, I designed ergonomic grips for a Formula SAE steering wheel. This is our first year running a custom steering wheel with an integrated dashboard, so we had to create grips from scratch. My first idea was to build the grips off a stacked acrylic model of the wheel, but ultimately I used an earlier revision of the aluminum wheel plate as my base.

Prototyping

To build my prototypes, I packed Chavant Clay onto my wheel plate in the handle locations. Then I bolted in a 3d printed dashboard enclosure. Since the enclosure was taller than the handles, I needed to add more clay which sloped up to meet the mounting bosses on the enclosure. Making the handles as thick as the enclosure made it feel less comfortable, so the sloped strategy was ideal.

To work on specific areas of the clay, I found it very useful to use a heat gun for local heating. This made the work area soft while keeping the finished areas solid. I also found it useful to  "freeze" some areas of clay using cold spray from an upside down compressed air can. This prevented me from accidentally mushing or denting finished parts.

For grooves, I used the loop tool to cut holes. Then I used the wooded handle to do final shaping. X-Acto knives and the thin sheet metal tool were helpful for cutting straight lines and even smoothing. I could also butt the loop tool against the aluminum plate to create straight edges on the handles.

Finally, I finished all the handles using a wet sponge. This left my clay with a great looking and smooth surface.

Ergonomics

I studied ergonomics by getting six of our team drivers to feel and comment on the prototypes. It was important to get the opinions of multiple people because everyone has different sized hands and different grip styles. The steering wheel needs to be comfortable for all the drivers in order to be effective.

The first feature I tried was adding finger grooves to the rear like many handles and grips. This was immediately shot down by most of the drivers everyone held the wheel differently. The grooves that were designed for my fingers were either too small or in the wrong positions for other people. So I scrapped that.

The second feature I tried was a boss on the side from the inside of the first knuckle to the hand web. This was also problematic for some drivers that liked to roll their inner hand on the wheel in steep angle turns. So I scrapped that.

The last feature I tried was a lower boss at the bottom of the hands. This could be used to assist with high g turns so that drivers could push down on it. In addition, drivers would be able to quickly home their hands if they needed to let go of the wheel. The drivers all liked this feature, so it made in into my final design.

Final Product

Including a few pictures from a photo shoot on the car :)

Process Poster