We spent this weekend working on the Acceleron IV booster getting it back into a working state for next week. We did a pressure test to make sure that everything is still fine, but we found out that the rocket was not holding pressure at all. We pretty quickly discovered that three of the Robinson couplings were missing their seals. Ooops. When we put those back in and everything checked out okay. We must have missed them during preliminary assembly.
We only pressure tested the rocket to ~100psi since the neighbours were out in their back yard, and having had this rocket fail a pressure test in the past, we didn't want to push it. We did have the video camera recording though just in case. The rocket will most likely get launched at 120psi on the day. The rocket theoretically should hold up to around 140psi operational pressure, with a burst pressure of around 180psi.
We hooked up all the electronics and and made sure the staging still worked when the pressure in the rocket dropped. We replaced the sustainer in the test with a small bottle full of water which fired as expected.
We replaced the rubber bands in the staging mechanism as keeping them stretched all this time in storage caused them to deteriorate quite badly. The same went for the wide rubber bands that held the fins on.
The booster segments are now attached with velcro straps which makes it a lot easier to service the segments.
The launcher has also had an upgrade with new longer fill tubes that allow us to use the spliced pairs of bottles on the bottom of each segment.
Some work has also been done on the sustainer. The altimeter has been moved into the space between the bottles which should help protect it. The altimeter is attached to the inter-bottle ring and having its own power supply allows us to swap it between rockets. We still have to re-attach the fins to the sustainer and also mount the new FlyCamOne2 camera to the payload section.
If we get time this week we also want to finish building a reinforced rocket that should be capable of around 180-200psi. It is only a two 1.25L Robinson coupled rocket but we are including the baffle we made a few months back to prevent the blow through effect with this rocket. The higher pressure would only make it worse.
We also made a couple of rocket carriers that help us transport and protect the rockets. They also help prevent the rockets from sagging in warm conditions.