|29th July 2023
|Whalan Reserve, Australia
|light winds, 18C Partly cloudy
Today we wanted test a small air-only rocket attached to a zip line. The intention is to use this rocket for a display inside the main hall of Macquarie University during the Astronomy open night in September. We will tie one end of the zip line to the stage, and then attach the other end of the zip line to one of the balconies on the third floor. The staff were quite keen for us to give this a go.
For this experiment, we attached one end of the zip line to a stand with the release head mounted to it near the ground level, and the other end we attached to the top of the Rocket retrieval pole about 5m in the air. We are using braided 316 stainless steel line that's 1.5mm in diameter. We bought a 50m spool of it.
We increased the pressure from 20psi to around 70psi on successive launches to get an idea how much pressure was going to be needed. It turned out that we needed around 65psi to make it go to the top of the pole over a distance of perhaps 20-25m. This was a good test because it showed that we need to bring a scuba tank to the uni rather than a bicycle pump, as getting 60psi with a bicycle pump is quite a bit of work.
Overall I think we can make this work.
This week I also did my L2 exam so I could attempt my L2 in September in Mullaley. Doing the on-line practice tests made it straight forward. Another item done on the check list.