Apparatus, methods, computer programs and non-transitory computer readable storage mediums for machining objects

An apparatus for machining an object, the apparatus comprising:

• a wheel having a circumference, the wheel including:
• a first circular surface;
• a second circular surface oriented parallel to the first circular surface;
• a first rim surface extending from the first circular surface at a first edge and defining at least a part of the circumference of the wheel, the first rim surface having a constant gradient between the first edge and an opposite end of the first rim surface, the gradient of the first rim surface having a radial component greater than zero;
• and
• a second rim surface extending from the second circular surface at a second edge and towards the first rim surface, the second rim surface defining at least a part of the circumference of the wheel, the second rim surface having a constant gradient between the second edge and an opposite end of the second rim surface, the gradient of the second rim surface having a radial component greater than zero, the first edge defining a first curved surface between the first circular surface and the first rim surface, and the second edge defining a second curved surface between the second circular surface and the second rim surface.