Aerotech Sparkies

[n3tjm]

I think it looks more like a slug of propellant, a sparky clog usually interupts the smoke trail before coming unclogged.

I seen this effect in the RMS 29/360 redline load. It had a bad grain but it was flown anyway. The motor ignited, rocket rose a foot, the spat a huge red fireball, and the flight continued normally.

 

[Viperfixr]

I think it looks more like a slug of propellant, a sparky clog usually interupts the smoke trail before coming unclogged.

I seen this effect in the RMS 29/360 redline load. It had a bad grain but it was flown anyway. The motor ignited, rocket rose a foot, the spat a huge red fireball, and the flight continued normally.

This flight over-achieved in terms of maximum altitude reached--beat the RS9 prediction by a 20% margin. I'd be surprised if any propellant was wasted!

 

[bobkrech]

I don't make motors, bit I am pretty sure that the magnesium couldn't be used in a composite sparky because it would all burn in the motor. They would have to use ridiculously large mesh magnesium to get the sparky effect. I know that BP motors can, but I read that it won't work in composites.

Someone please correct me if I'm wrong.

Sam

Sparky motors have very large mesh particles. In the case of titanium, the particle size is just over 2 mm!

The particle size in standard motors can not exceed 150 um (0.006"). This insures that the propellant burns primarily inside the motor. To get a sparky effect the metal fuel particles must be large enough to exit the nozzle largely unburned, and then afterburn in the air.

Magnesium particles will burn with the oxygen in the air, while titanium will burn with both the oxygen and nitrogen in the air.

Bob