#2 The first year at the School of Jewellery.... (Part 1: Filing a Cube)
As you may know from my Instagram feed I started studying for a degree in Horology at the School of Jewellery in Birmingham. The course itself is a BA, and lasts for 3 years like most university degrees here in the UK, however, there is a high focus on practical work. Initially I was unsure of how to become a watchmaker but luckily in England there are a few options to chose from. The main options are:
- The BHI (British Horological Institute) distance learning and technician qualifications
- BA (Hons) Degree from the School of Jewellery, Birmingham
- West Dean College
I chose the degree route as it offers a wide range of topics to give a broad but concise understanding of all things Horology. From watch and clock repair and bespoke making, business and commercial skills, the history of timekeeping and CAD (computer aided design)- the course covers these along with much more! The school has a vast amount of quality workshop tools lathes, pantographs and milling machines to name a few and also has quality specialist horological tools to use so it is the perfect location. I can also study for the BHI accreditation alongside my degree studies.
The year kicked off with a project that a lot of horologists will be familiar with- making a cube from a brass bar stock, using only hand tools. This task is designed to develop skills when working with hand tools and working to fine tolerances, it also helps to bed in new files. The roughly cut ends are firstly filed so that they are perpendicular to the sides, the accuracy of these is important as they work as datum reference points for the rest of the project. This is regularly checked with a set square.
As with everything it is better to make a plan before starting. Using the Pythagorus theorem the theoretical maximum width that each face of the cube could be worked out. In this case for a 25mm round bar it would be 17.67mm. When filing I checked how close I was to this measurement whilst also checking the squareness, when reaching the measurement a finer cut of file is utilised to make fine adjustments.
The bar is intentionally left at length until closer to the end as although it means extra material has to be removed, the additional material helps to steady the file on the work.
The bar length is then cut down to a few millimetres above the maximum face width and filed to the correct dimensions. Each side was checked against the dimensions using a micrometer in 3 positions on each which allows me to check for potential high spots.
The brief specified that 3 faces were to be straight grained and the other 3 mirror polished. The filing marks are removed first with abrasive paper, steadily going up the grits to 2000 grit and lubricated with a water and Fairy liquid mix- this helps to flush the waste brass away. The papers are fixed to a flat piece of glass or acrylic and the work is applied to the papers in a figure of eight motion. The mirror finish is created with lapping film and the same process is used. Care has to be taken with lapping film as the waste material likes to get embedded in the abrasive and scores the polished surface. Liquid polish was not used as there is a very good chance that the sharp corners and edges would end up being rounded. The straight grain is applied using 600 grit abrasive paper. Again, the paper is fixed to a flat surface. A plastic ruler is placed on top of the abrasive and the work is pulled along the paper whilst resting on the ruler. It is important to only go in one direction (not a back and forth motion) as material can collect in the paper and could cause undesirable and unsightly score lines.
The project was completed and I ended up with a very good finish on all sides. The accuracy was also excellent- I was pretty much bang on my calculation and I managed to achieve a tolerance within 0.03mm on all sides. Not a bad effort if I do say so myself!
Hope you enjoyed this post and don't forget to follow me on Instagram @morningtonwatches