telescope build: work in progress (1)

At each end of each of the three main sections of the telescope there will be one of the main rings. Each ring will consist of two elements fixed together. One of these elements will be made of marine plywood with a thickness of 25 mm; the other will be made from aluminium plate. The aluminium ring components at each end of the telescope will be 3 mm thick, and those in between (I.e. at the joints between the main sections – see introductory blog post) will have a thickness of 6 mm.

I began the build by cutting discs from aluminium plate on the floor-standing drill press using a circle cutting attachment:

The aluminium parts of the main telescope rings will be cut from these discs.

The circle cutter left a very ragged edge, so the burrs were first roughly removed with a file, after which the discs were stacked on a mandrel and bolted together via holes which were drilled in the central area which will in due course be cut out and consigned to the recycle bin. The edges were then gang milled on a rotary table on the milling machine before being polished with a variety of fine abrasives.

The holes in the end rings will not all be the same size as those in the others, but every ring will have twelve holes. Accordingly, the hole positions were lightly marked using a dividing plate on the rotary table and a centre drill in the mill:

The next step on the rings will be to start drilling the holes...