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.
Robert provides an update on his recent round of static tests and rehearsals before the firing of his 250lbf liquid rocket engine in its rocket configuration.
What I found of most interest was the below,
LOX fill technique – During the previous tests, I was unable to completely fill the LOX tank. For these tests, I used a modified fill technique which involved closing the LOX vent valve first, waiting a few seconds, then closing the LOX fill valve. This allows the 20 psi or so in the dewar to compress the ullage in the tank and get some more liquid in. I also added some temporary foam insulation to the tank and fill lines. As a result, the LOX tank pressurized in less than a second instead of the almost two seconds previously.
Always good to read these little hints and tips to put in the back of the mind for future use!
The update is full of bullet points so it is easier to post the link.
I have been a bit slack in reporting this update but here it is.
Robert continues to post on his liquid fuelled rocket project, this latest update covering the avionic systems the rocket will entail, more so the flight computer. Robert has posted a nice breakdown of how the board will function and the components involved.
You can read Roberts update here. See more rocket project picshere
Robert Watzlavick has posted a new update for his liquid fuelled rocket project. The update, dated 19/10 and found herecovers his progress thus far in plumbing his rocket, one of the many pictures is shown below.
The rocket is 6in in diameter and is powered by a 250lbf lox/kerosene regeneratively cooled rocket engine of his own design, the rocket itself features custom made main propellant valves, helium manifold and vent valves, plus many more extras.
Read the full update as linked to above and check out all the other pictures from this very nice project here.