I’m Louis Scholes and I’m a degree apprentice engineer at Tribosonics. I started working for Tribosonics and studying at Sheffield’s AMRC training centre in September 2019. I wanted to pursue my interests in engineering as a career.  

Prior to starting as an apprentice engineer, I completed an Extended Project Qualification. It required me to plan, manufacture, and document an engineering related project. My greatest interest is in vehicles and so I settled on a motorbike. Using Google for inspiration, I came across the 60’s style American mini bike. It would be the most realistic design to replicate given the available resources. 

Beginning with a frame of the correct size for the chosen power plant, a 50cc motorcycle engine. The right way to do this is to measure the distance between all the engine mounts. Then design a suitable frame before touching any tools, to avoid mistakes. However, I decided I didn’t need to bother with any of that measuring malarkey, so I put the engine on a pallet and started bending the frame tubes until they looked about right. Much to my surprise, the result was both reminiscent of what it was intending to be, and somewhat dimensionally correct!  

After fabricating the frame, I created mounting points for all the components of a motorbike, the main ones being a fork, engine, exhaust, seat, wheels and fuel tank. Aside from the engine, I decided I wanted to make all the main components for the bike myself. This was mainly down to the fact that ‘off the shelf’ components would be expensive, and I would likely have to modify them to fit anyway. 

Fixing the fuel tank

For the fuel tank, I dissected a length of old stove pipe and delicately shaped it using a large hammer. After completing the shape, I attempted to weld the flimsy sheet metal together with questionable success, before quickly grinding away the evidence! I tested the tank using water to find any leaky spots. Once the problem areas revealed themselves I then re-welded and tidied up.

The most complex part of the project is enabling drive to a rear wheel that was not designed to be driven that way. I found that the problem was the rear wheel needing a sprocket and brake disc mounted to it. Only one side of the wheel had provisions to mount anything to it. Fortunately, the wheels are in two halves that split down the centre. The solution was to take the two identical halves of separate wheels and use them both to create one with mounts on each side. They also only come with very small bearings which I suspected may become an issue at some point.  

Test Ride

I decided the best way to see if this setup would be up to the task was a test ride, and after making an exhaust pipe and assembling all the unfinished main components, it probably still wasn’t ready for one, but I couldn’t help myself. After breaking out the cable ties and duct tape, the first test was underway.  

Testing it revealed an issue with the rear axle: it is not in ideal shape. A longer than ideal length and not a large enough diameter meant the axle didn’t stand a chance, back to the drawing board on that one. The short ride also highlighted the need for a decent seat! 

The solution to the axle problem is machining a large bore in the spacer that would house a much larger bearing. The axle diameter was also increased, accommodated for by another machined spacer.  This would bring the load closer the bike’s frame reducing the forces on the axle itself. Another test proved this theory to be correct and the issue was resolved. 

The basic engine only required a few electronic components to run, namely a coil and Regulator/rectifier. Then, I assembled these components into a basic wiring loom and after squeezing it into a seemingly impossibly small box. The bike was complete!

Reflecting on the project as an Apprentice Engineer

At first, the assembly of the bike was easygoing. It was a great feeling having seen the project through from the start and very satisfying to finally assemble it. After collecting all the components, I tried to make a suitable seat. I decided to outsource to my Grandma, who made a far better job of it than I could have. I think it really completed the project.  This experience will really help me as an apprentice engineer.

Reflecting on the project, it is interesting to think about all the challenges and how I would approach them now. Since completing the minibike, I have had six months of apprentice engineer training at the University of Sheffield’s AMRC Training centre. During this time, I developed my knowledge of machining and manufacturing, and recognise mistakes and weaknesses in my previous work. There are definitely areas that could be improved with a little more forward planning. I look forward to my next project and putting this newfound knowledge into practice. 

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Tribosonics is an innovation-led scale-up with a strong challenger mindset. We drive transformation by using its unique sensing technologies to address challenges in tribological contacts (wear, friction and lubrication).

Located and forged in Sheffield, it serves global markets in Transport, Power Generation and Manufacturing.

Arrange a discussion to find out how Tribosonics can add value to your business. Contact: Christina King, c.king@tribosonics.com