Adrian --
Did the 6-inch(ish) G12 motor kick partially out of the booster or was flown that way to make room for recovery ?
Thanks !
-- kjh
EDIT: Thanks for the Data Files ! Q: what was the site temperature ( more -or- less ) ?
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Taking a shot at the G record
- Thread starter Adrian A
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Did the 6-inch(ish) G12 motor kick partially out of the booster or was flown that way to make room for recovery ?
Thanks !
-- kjh
EDIT: Thanks for the Data Files ! Q: what was the site temperature ( more -or- less ) ?
Checking out the data, here is the acceleration of the apogee deployment:
-Z is the direction of forward movement. Lest you think that the charge was over-sized to cause 300 Gs of acceleration, only 0.17 grams of BP were used in this flight. Everything is just very light. You can see 3 sets of reefing tape break before the shock cord goes taut.
Here's the acceleration from liftoff to the apogee deployment:
The -Z axis is the motor thrust direction. After the initial kick, the dual thrust motor throttles down and keeps going for a total of a 12 second burn. In the meantime, the centripetal acceleration measured on the X and Y axes exceed the motor thrust.
The baro altimeter shows a pretty big transonic effect but then matches up pretty well with the GPS altitude once it slows down. The inertial altitude is low because early on in the flight, the the inertial navigation thought the rocket was more tilted than it actually was:
Here are the gyro measurements for the first part of the flight:
The roll axis (Z) sensor maxed out about 4 seconds into the flight. The gyro data in the early part of the flight is interesting:
Starting at liftoff, you can see some noise from the rocket bouncing around in the tower, which is normal, but then is a bunch of action around 0.5 seconds into the flight. It shows up a bit in the acclerometer data also. The roll rate weirdly goes down a lot between 1.2-2 seconds and then goes back to following the velocity profile.
I'm guessing that the violent wiggle around 0.5 seconds might be from fin flutter at a resonant velocity? Usually it gets worse as the velocity goes up though, so I'm a little mystified. In the lower plot the accelerometer data is zoomed in enough so you can see some individual impacts inside the 12' tower.
Here's the rocket tilt:
The apparent straightening of the rocket at 3 seconds is a little surprising, but there was a very distinct wind shear layer that you can see from the GPS plot:
The ground track starts at the top, and the rocket started out weatherocked into the SW wind. But then it drifted on the NW wind until it got back down to the surface layer.
-Z is the direction of forward movement. Lest you think that the charge was over-sized to cause 300 Gs of acceleration, only 0.17 grams of BP were used in this flight. Everything is just very light. You can see 3 sets of reefing tape break before the shock cord goes taut.
Here's the acceleration from liftoff to the apogee deployment:
The -Z axis is the motor thrust direction. After the initial kick, the dual thrust motor throttles down and keeps going for a total of a 12 second burn. In the meantime, the centripetal acceleration measured on the X and Y axes exceed the motor thrust.
The baro altimeter shows a pretty big transonic effect but then matches up pretty well with the GPS altitude once it slows down. The inertial altitude is low because early on in the flight, the the inertial navigation thought the rocket was more tilted than it actually was:
Here are the gyro measurements for the first part of the flight:
The roll axis (Z) sensor maxed out about 4 seconds into the flight. The gyro data in the early part of the flight is interesting:
Starting at liftoff, you can see some noise from the rocket bouncing around in the tower, which is normal, but then is a bunch of action around 0.5 seconds into the flight. It shows up a bit in the acclerometer data also. The roll rate weirdly goes down a lot between 1.2-2 seconds and then goes back to following the velocity profile.
I'm guessing that the violent wiggle around 0.5 seconds might be from fin flutter at a resonant velocity? Usually it gets worse as the velocity goes up though, so I'm a little mystified. In the lower plot the accelerometer data is zoomed in enough so you can see some individual impacts inside the 12' tower.
Here's the rocket tilt:
The apparent straightening of the rocket at 3 seconds is a little surprising, but there was a very distinct wind shear layer that you can see from the GPS plot:
The ground track starts at the top, and the rocket started out weatherocked into the SW wind. But then it drifted on the NW wind until it got back down to the surface layer.
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It partially kicked out. The temperature was around 50F.
Impressive! That's higher than my max altitude, and I was using a K engine....
Mine too ( 13.8 K ft on K700 ) !
I'm testing the latest version of the Featherweight User Interface phone app, and one of its new features is to export the tracker recorded data as a .kml file. Here's the Google Earth view of the flight:
Nice! I guess we won't need fw2kml down the road lol. Are you going to add more tags for flight events? or other details?
I might like to. Launch and landing would be nice. Do you have other ideas?
Thanks to you and @Arpak for your work on the .kml converter. My developer was able to add this capability quickly because of your work. Next time you want to order something let me know and I'll show my appreciation.
Arpak
Well-Known Member
Was a fun challenge! Thanks for making a killer piece of kit.
Ejection charge/parachute deployment would be nice if you have that information, or can infer it from the data. Another thing I was thinking about adding to the landing marker is lateral distance from launch pad, so that's worth considering.
E: in the same realm as EC/parachutes, airstart/stage tagging would be cool too.
Adrian,
I focused on your ~1 second flight anomaly during boost between 1 & 2 seconds flight time. This cannot be real data. All three accelerometers producing almost identical patterns with just an offset. A straight line jump into and out of the event with normal data before and after. The roll rate gyro is also a very close match to the accelerometer pattern even in recorded values.
I focused on your ~1 second flight anomaly during boost between 1 & 2 seconds flight time. This cannot be real data. All three accelerometers producing almost identical patterns with just an offset. A straight line jump into and out of the event with normal data before and after. The roll rate gyro is also a very close match to the accelerometer pattern even in recorded values.
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What data are you plotting in the first plot? The accel data from the flight looks like this during that time:
There us a little wiggle in the accel data around 0.5 seconds that corresponds to larger gyro activity, which makes me think that that gyro oscillation is real. But for the Gyro Z-axis weirdness around 1.5 seconds, there is no corresponding accelerometer activity, so that make me think it is some kind of artifact or anomalous data.
Both graphs are from your high_rate_4-21-2024 CSV file data, posted on 4-22-2024. It appeared to me as a high G range switch over.
Try downloading them again. I wondered if the file that I posted was corrupted, so I just downloaded it and plotted the accels in Excel. Here's what I got from the high rate file, matching the Matlab plotting from above:
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