An update on Roberts rocket project as he works towards the flight of his 250lbf liquid fuelled rocket. Robert has been working towards a full up static test of the rocket, with thoughts on how to use his existing infrastructure to conduct this.
The existing test stand structure will be reused but extra components have been added to secure the rocket vertically. Two 8-foot 3030-S beam extrusions from 80/20 Inc. will be attached to the test stand and supported by aluminum angles. The 80/20 beams are more than I need for this application but I plan to use them later during final assembly to help with alignment of the skin to the frame. The rocket will be mounted 6 inches away from the beam using 3 x 6 x 1/4 inch square tubes as spacers. The thrust load will be reacted through two 1 x 1 x 1/8 inch angles that tie into the injector manifold at the top of the engine and then to the vertical beam.
Robert also talks about modifying a CDI ignition system to provide feedback before opening the igniter valves, this guarantees 100% the sparkplug of the igniter will be working when the propellant is passed through it, thus allowing the main engine to be ignited.
One feature I wanted onboard was feedback from the CDI ignition module to verify it is working before opening the igniter valves. However, the CDI power supply comes from an isolated offboard source so I had to design an optoisolated current monitor circuit that ties into the onboard data system
I have just personally ordered a CDI ignition system for my own project so it will be interesting to see how this works out.