Young Engineers - Soap Derby Kart

In 2025, the chairman of REMAP Peter Livingstone donated their soap box kart to Felsted School. This was done as an attempt to continue their legacy of entering the annual Billericay soap box racing competition. The task was given to the Felsted Young Engineers team, who were keen to take on another project. They wanted to improve the kart while maintaining and supporting the legacy of the charity REMAP. 

We (Young Engineers) needed to find a new client for the derby kart to take part in the gravity race. This is where Mr Cudjoe came along (he has no option really). Part of the brief is to make the racer bespoke and designed around him. We have to consider ergonomics and anthropometric data, making it comfortable and enjoyable while keeping the kart aerodynamic, and also giving him a chance of winning.

We planned and designed the racer with our clients input using Onshape, and started the process of making it in the workshop, dividing tasks and ticking them off along the way.

Our first original idea for the kart was to have a triangle on the sides with a curved storage area on the back, but we weren't sure this would win marks for the creativity idea. At this stage we hadn’t designed an idea from the front of the kart.

Next we wanted to design a more fluid looking car that would also fit the shape of the designs better. To do this we took inspiration from a kart on Facebook Marketplace which had a curved front bonnet. But for our design we wanted to mirror this design on the back of the kart to add some symmetry while maintaining the aerodynamics.

We want to make the break as ergonomic as possible for our client. To do this we planned to use clay or some form of mouldable putty and then get our client to grip the moldable substance, this would then give us the exact grip of our client to make the handle as ergonomic as possible. We would then use our phones to create a 3D scan of this to shape, this creates a high quality and detailed image by using iphone LIDAR sensors. The shape was then isolated and uploaded to the CAD software on Onshape. On this software we filled the shape and then created a hole going through the centre of it starting at the bottom for the handlebar to go through. Next we uploaded this file to a 3D printer which resulted in a very ergonomic handle that is a direct replica of our clients grip.
 

After making the kart, we had to carry out and conduct testing to ensure the steering and brakes work, as well as the stability to make sure that it fits the client’s expectations and is safe to go downhill. We made sure to thoroughly test the kart with a wide range of scenarios that would mimic what the kart would actually have to go through (eg. speedbumps to represent ramps), this was done with a wide range of people to make sure that the kart was safe for everyone. This made sure the client’s kart was ready for them to race.
 

Mr Cudjoe entered the kart in this year's CSES (Chelmsford Science and Engineering Society) competition. This was held at Anglian Ruskin University. We created a slide presentation to put up for the judges as, with the kart on display. We had a lot of conversations with different judges, other students and teachers. This was also a good opportunity to see other students' projects and vote for 2 of our favourites. A spokesperson gave a brief explanation of University life and offered information for the process of career path and choosing the right course.