idle curiosity

a few years back I had an idea for a varient of a piston launcher*...one of the questions that occured to me was how long a period of time is between visible flame and and say 3oz of thrust for an 18mm motor? less than 15millisenconds or greater than 15msec? if greater, then it would have worked.
thanks,
rex
*never built due to other nagging questions like; can the rocket withstand an acceration of 1000g....

I haven't the faintest clue about the pressurization time of an Estes motor, but I would be very curious to see the design...

Rex R said:

a few years back I had an idea for a varient of a piston launcher*...one of the questions that occured to me was how long a period of time is between visible flame and and say 3oz of thrust for an 18mm motor?

Click to expand...

For EMMR's first video contest I shot video of an Estes Snitch taking off from a variety of angles. One of the angles was from directly beneath the Snitch.

You can see the video here.

The frame rate, if I remember correctly, was 30 fps. If you walk through frame by frame you can see that the first frame after the igniter plug is present already shows a pretty good sized flame. Time between the two frames is roughly 33 milliseconds.

Hope that helps.

And thanks again to Nick for running all those great contests at EMRR.

Steve

ah, so it would have worked, presuerization time for the cylinder(under the 'piston') averages about 10-15ms. one of the other questions was; 'with a launch velocity of 500-600 ft/sec do I really need a rocket motor?'...I decided that I didn't . simple concept & design, some 4" pvc, 8' of 2"pvc, an 80mm case fan, & 209 ml of propane...ignite the rkt motor and launch would have occured approximately 45ms after the engine fired. two sticking points, a stable vehicle that would fit, and the piston/sabot design. I stopped working on it after some one mentioned that the BATF wouldn't like it...(something about them considering it to be an rpg launcher).thanks for satisfying my curiosity.
rex