Nozzle & Thrust chamber:
We simplified the outside of the nozzle contour for ease of manufacturing on a manual lathe. The 40mm copper insert was pressed fitted into the nozzle therefore removing the need for a garter spring. The 25m throat, as well as the convergent and divergent sections, were machined afterwards.
The thrust chamber was made from a 80x15mm tube and machined down to an OD of 76mm with an ID of 50mm. Injector recess ID 65mm.

Injector & Flanges:
Following closely the MS standard design but modified to receive a 65mm shaft retaining ring and dual 60X2.5mm NBR 70 O-rings. Oxidizer holes: 6x 2,5mm; fuel holes 6x 1,9mm. AN6 fittings and a pressure sensor to measure chamber pressure. There are questions on the use of NPT but the MS designers were right on selecting this NPT thread. We had our doubts as well but it proved to be the right choice for this design. Good for blind holes in the injector, also for aligning and the avaiability of cheap connectors i.e. the NPT –> AN6.
The flanges were ordered at a local shop which had a nice webshop wizard to create custom flanges – no need for uploading drawings / .dxf’s. OD 100mm, ID 65,5mm, PCD 84mm; 8x 6.5mm holes made from 6mm thick steel plate. Test fit of the thrust chamber went OK. Used an oversized 82x43mm grafite gasket with st.st. inlay which was cut to the required dimensions between 2 discs. Threaded rods are M6.