We spent this weekend in the workshop repairing J4 II after its explosion last week. We basically replaced all the bottles with new ones, as some of them had been in use for 6 months or more. All the brass couplings were replaced with new Aluminium ones, reducing the rocket weight further.
We also taped all the inter-bottle rings to the rocket with a wide flexible tape, similar to electrical tape. This made the rocket much more solid.
We also reconfigured Hyperon III into a 3 bottle configuration as it will fly a long payload section when the weather clears up. Hopefully next weekend.
We also finally ordered a couple of altimeters last week, so I am hoping they will arrive this week. If they arrive in time, we should be able to fly them on the next launch opportunity.
We've also been working on a new simple and compact electrical pressure switch which we hope to test in the next few days. The prototype only weighs 10 grams but it should be possible to reduce that down further. The purpose of the switch is to serve the same role as the TDD, but without the exposed external moving parts. We use a TDD to detect when the pressure drops inside the rocket (at burnout) to activate the staging mechanism.