Monday, 9 March 2009
Preliminary tests on KNO3 solid fuel rocket motor have been interesting. I'm not sure I was quite prepared for the volume of smoke to be generated - neighbours certainly weren't - Diploville was briefly plunged into a dense smog Sunday afternoon but a stiff breeze soon cleared things enough for us to inspect the damage. The copper tube is being used for test purposes,to be replaced in production by cardboard tube lined with aluminium foil to save weight. Since this shot of a 7.3 second burn we've been experimenting with nozzle geometry and a little bit of venturi effect. No thrust details as yet. We're making a rig for tests using a spring balance. Slightly blurred image due to a combination of factors!
Accurate, digital scales are a great help - brilliant for these sort of projects as they are zero-able at the touch of a button. Very expensive Swiss stainless cookware is optional but it's always a pleasure to use good kit. MORE SMOKE !