Last Flight of the Nova Payloader

[DanielLW]

I've had this rocket for quite a while... and finally crashed it.

Motor was an "experimental" Aerotech D12-ish. I have a bunch of old 18mm Aerotech B and C reloads and found I can combine 2 C grains in one liner to make a D. Should have put more black powder in the end, though...

Stick with the video after the first liftoff. You can actually see the rocket hit the ground towards the right of the frame. There are multiple angles. First two angles are at 240fps and 120fps slowed to "240".

The actual boost phase was pretty spectacular. It went up like a shot!

Edit: When you watch the video, if you have your sound turned up, you can hear it whistling as it comes in ballistic.

[video=youtube;5qJ2eeoxqJ8]https://www.youtube.com/watch?v=5qJ2eeoxqJ8[/video]

 

[Rex R]

looks like you didn't get the ignitor far enough forward. that is what usually causes 'chuffing'.
Rex

 

[DanielLW]

looks like you didn't get the ignitor far enough forward. that is what usually causes 'chuffing'.
Rex

The igniter was all the way forward, and had a little bit of blue thunder propellant with it. This is really old (about 20 years old) white lightning propellant grains I'm working with, and so very hard to light. They had expanded a little so I had to shave them to get them to fit. I also had to widen the notches in the grains (again due to expansion). On a prior attempt I didn't notch out the grains, and the motor blew the ejection charge about 20 feet off he ground. The forward o-ring was partially melted, so I figured I over-pressurized the motor. And so what I did for this one is I drilled out the nozzle to be a little bigger (it is originally a C6 nozzle) and widened the grain notches to make sure there was a clear path for the motor to burn correctly. Seemed to work great, except for not having enough ejection powder.

 

[Rex R]

FWIW Aerotech 24mm motors come with 0.5g of BP
Rex

 

[mwtoelle]

My experiences with old (more than 15 years old) Aerotech delays is they tend to run long. That is, if you can get the motor to light. Did the delay element even light? I had that happened to me on a B6-2 reload flight back about 1994. Other that incident I have had only good experiences with the 18mm B & C reloads.

 

[DanielLW]

My experiences with old (more than 15 years old) Aerotech delays is they tend to run long. That is, if you can get the motor to light. Did the delay element even light? I had that happened to me on a B6-2 reload flight back about 1994. Other that incident I have had only good experiences with the 18mm B & C reloads.

This delay did burn through. But I have had one that didn't. Ever since that time I've shaved off the surface of my delays to make sure there is a fresh surface exposed to the burn. Since I've done that, I haven't had any unburned delays.