L2 Certification, Purchasing

Purchase of Parts

I’ve made another purchase of parts for my build. I have ordered:-

  • Raven 3 (70G)
  • 84 inch rip-stop nylon conical parachute, ~16 inch spill hole
  • LOC ANGEL Drogue Parachute
  • Tubular Nylon 0.5625 inch (per metre)
  • NOMEX 12×12 for up to 4 inch Tube
  • Remove Before Flight tag (Pink)

I discuss my choice of component below.

Raven 3 (70G)

Manual is downloadable from:-

http://www.featherweightaltimeters.com/uploads/Raven_Users_Manual_13April24b.pdf

This is a very well spec’d altimeter. It beeps a lot when you turn it on to alert you that things are operational and satisfactory (though many probably do)

It is a very light, small sensor. This will leave plenty of room for other components, etc inside the rocket. Unfortunately it doesn’t have a gyroscope, but there is nothing stopping me installing my own gyroscope sensor/electronics.

However it is a popular, well proven piece of hardware.

84″ Main Parachute

This has been sized to lower the rocket at approx 6ms-1. This is an upper limit. I suspect it will lower the impact speed will be a little lower. This parachute has also been chosen because it is of stronger construction, which I think will be necessary because the rocket will be travelling ~22ms-1 when it is deployed. This is fairly high speed deployment.

NOTE: Blake from AusRocketry has suggested that using a LOC ANGEL parachute (large?) would do the job well and might be easier to pack into the parachute bay. Using the calculations on the webpage with known weight of the rocket, we would be looking at a decent speed of about 5 ms-1.

LOC ANGEL Drogue Parachute

I really wanted to get a 28″ or 30″ Drogue, but they seem hard to come by. This is a 24″ drogue and checks have shown that it SHOULD reduce the speed of the rocket to about 22ms-1. If I see/learn of reasons for a major deviation upwards, will need to consider purchasing an alternative Drogue Chute.

NOMEX 12×12 for up to 4 inch Tube

This is wrapped around the Parachute to protect it from the exhaust gases. I expect that this will be attached to the shock-cord, so we don’t lose it at ejection.

I got two of these, one for the Drogue, the other for the Main parachute.

Remove Before Flight tag (Pink)

I’m going to have ONE switch to turn everything on/off.  I didn’t really want Pink coloured one, but there weren’t many others.

Later I convinced myself that Pink is just fine, infact it is highly visible and should be no missing it!