I've got some experience with the basic eggtimer flight computer, which I understand is a barometric sensor based flight computer. I'm now working towards my L3 and needing to invest in a 2nd flight computer to meet the redundancy requirements.
I've heard that for an L3-cert level flight, it's wise to have the 2nd (primary) flight computer include an accelerometer in addition to the standard barometric sensor. I assume this is particularly useful if one goes to an extreme altitude where barometric sensors don't work as well for triggering drogues at apogee, or if the rocket exceeds mach 1 and distorts the pressure reading. The eggtimer's documentation makes me think the designer was aware of this problem since it states "Filtered altitude/velocity sampling to eliminate false triggering of ejection charges due to mach transition."
However, there really aren't all that many flight computers that include an accelerometer, and they're all pretty high priced. From looking at the old chart at https://rocketsetc.com/altimeter-comparison/, my options for a dual-deployment are limited to the models below, which are all a lot more expensive/complex than something more familiar like the eggtimer quark or RRC3 I was hoping to use. (Unfortunately, the Adept22 appears to be no longer available).
Anyone care to share their experiences on how necessary an accelerometer is? From a brief skim through other's L3 build docs, it looks like some people go with barometric sensors only, though many do indeed use an accelerometer.
If you've got other options for accelerometer flight computers not shown on the list below, feel free to post them too.
For reference, I'm looking at hitting Mach 1.2 and 10k feet on my L3 cert flight. Should be well within our field's altitude limits.
I've heard that for an L3-cert level flight, it's wise to have the 2nd (primary) flight computer include an accelerometer in addition to the standard barometric sensor. I assume this is particularly useful if one goes to an extreme altitude where barometric sensors don't work as well for triggering drogues at apogee, or if the rocket exceeds mach 1 and distorts the pressure reading. The eggtimer's documentation makes me think the designer was aware of this problem since it states "Filtered altitude/velocity sampling to eliminate false triggering of ejection charges due to mach transition."
However, there really aren't all that many flight computers that include an accelerometer, and they're all pretty high priced. From looking at the old chart at https://rocketsetc.com/altimeter-comparison/, my options for a dual-deployment are limited to the models below, which are all a lot more expensive/complex than something more familiar like the eggtimer quark or RRC3 I was hoping to use. (Unfortunately, the Adept22 appears to be no longer available).
Anyone care to share their experiences on how necessary an accelerometer is? From a brief skim through other's L3 build docs, it looks like some people go with barometric sensors only, though many do indeed use an accelerometer.
If you've got other options for accelerometer flight computers not shown on the list below, feel free to post them too.
For reference, I'm looking at hitting Mach 1.2 and 10k feet on my L3 cert flight. Should be well within our field's altitude limits.