User`s manual

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bring that stage down, it should be timed to pop right around the first stage’s projected apogee.
You may have to model the first stage’s flight separately from the second stage to determine this
value, but it will usually be a few seconds after second stage ignition because the added drag will
slow the first stage rather quickly.
This example is for a rocket with a Thrust/Weight ratio of over 10/1, so the default 200’ LDA
setting will work fine; in fact, we don’t really want to increase it, because that will delay the
Burn Timer’s start.
We are assuming that the main motor will fire for approximately two seconds, and that we want
a 1 second delay after burnout before firing the second stage. If we know that our igniter will
take about one second to ignite the second stage motor, the actual delay from burnout will be the
one second, which happens to be the delay that we wanted. Therefore, we will set the Airstart
Delay to zero which will fire the igniter as soon as the Burn Timer ends, with the second stage
motor igniting about one second afterwards. We also increased the CHB On-Time to 3 seconds
(from 2), since the igniter may take longer to heat up than a simple electric match used to fire
ejection charges. We recommend that you test the igniter-motor combination on a single-stage
flight first or consult other club members, forums, etc., so you have an idea of how long it takes
that particular igniter to fire that particular motor.
Eggtimer Build_1.45 Flight Settings
T:23.50
A 200 LDA <50-500 by 50> P:97804.00
B 20 Burn/Coast Samp/sec: <4,5,8,10,15,20,25,33> A:975.39
50 Interval (ms) Main:0
C 1 Descent Samples/sec <1,2,4,5,10> CHB:0
1000 Interval (ms) Batt:3.12
D 1 Main Enable <0-Off, 1-IGN, 2-Servo CCW, 3-Servo CW>
E 500 Main Altitude <100-2000 by 50, 0 @ Apogee>
F 2 Main ON-Time <1-9, 0-Cont.>
G 4 CHB Enable <0-Off, 1-IGN, 2-Servo CCW, 3-Servo CW, 4-Airstart>
H 3 CHB ON-Time <1-9,0-Cont.>
I 2 Burn Timer <1-20>
J 0 Airstart Delay <0-9>
K 0 Telemetry
O Comments: Airstart example
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