Using the same reloads as I described in my other post. E18W-10, 24 mm RMS.
wRASP said that I needed a 4 second delay to get to apogee with my 9.5 ounce Phoenix. The delay for the E18s were 10 seconds. Here are the calcs....
10 second delay, 2 second motor burn, 12 second total delay element burn. 16mm long delay element 16mm/12 seconds = 1.33 mm/second burn rate.I needed 4 seconds delay plus 2 seconds burn so 6 seconds total.
This one is easy cuz 6 is half of 12 so I needed to drill in 8 mm to get to
6 seconds. I left it just a little shy of the full 8 mm so it goes after the turn at the top. It went off just after the turn at the top.Same motor for the Airspike. wRASP says I needed 6 seconds.
6 second delay plus 2 second burn = 8 seconds. 12 seconds - 8 seconds means I have to remove 4 seconds.4seconds at 1.33 mm/second = 5.33 mm
I drilled about 5 mm and got an ejection right at the top.
My son was timing the burns, but I think he started at first smoke instead of liftoff (when the real burning starts). These old white lightnings are tough to light. He got about 8 for the Phoenix, which should have been 6. I guess I shoulda let him push the button and leave me to do the timing. Next time.
I would expect that there is at least a little delay between grain ignition and delay ignition, which may account for part of the "bonus delay" that we always here about. I would expect it even more here since the E18 does not fill the whole case and has the masking tape at the end of the grain for the ignitor to butt against. The F's that fill the whole case would probably ignite both nearly simultaneously, minimizing that difference.