Blue Raven - How to Force Download Flight Data

[kjhambrick]

@Adrian A --

I flew my Blue Raven in a BT-55 Vulcanite on a Quest E26-7W last Saturday in Dual Deployment Mode.

The main did not come out and the MJG ignitor and 0.6 gram BP Charge did not fire.

The rocket came in on a streamer from apogee and the rocket landed tail-first on an asphalt road.

More details here: Quest E26 and La Pequeña Vulcanita 34 and Ouch !

Anyhow ...

When I returned to my prep table I was able to power on the Blue Raven via the Mag Switch without touching the battery.

However, it did not auto-download any flight data.

I shut it down and then did a force-stop on the Blue Raven App on my Android Phone and restarted the Blue Raven and then the Android App and it showed a zero-length file.

Android Screen Shots are below -- there does not appear to be any data.

When I try to [Share .csv] on my phone, I get a message: Exporting low rate file (1/2) and the app hangs.

So my Qs are:

Q1: Is there a way to force an export of the raw data from the Blue Raven via my phone ?

Q2: Is there a new version of the FIP Program for the Blue Raven to download raw datafiles ?

Thanks Adrian !

-- kjh

p.s. I imagine it is too late to save this particular flight data because I was worried that maybe I damaged the Blue Raven so I did a series of ground tests and sims yesterday to make sure the Blue Raven still 'fired' christmas tree lights ( it does ).

I'll check the ignitor later today after work via a Blue Raven Ground Test when the rain is supposed to let up a bit ...

These are the four screen shots of the flight summary after the crash

 

[kjhambrick]

Continued ...

I ran a ground test with the unfired EJD ematch just now and it fired as expected.

I must have had a momentary blackout, maybe at apogee due to the charge ?

This is the video.
View attachment gnd-main-ejg-1698073867813.mp4

Note that the audio and video are out of sync but the ematch did fire as expected.

Thanks again @Adrian A !

 

[Adrian A]

@Adrian A --

I flew my Blue Raven in a BT-55 Vulcanite on a Quest E26-7W last Saturday in Dual Deployment Mode.

The main did not come out and the MJG ignitor and 0.6 gram BP Charge did not fire.

The rocket came in on a streamer from apogee and the rocket landed tail-first on an asphalt road.

More details here: Quest E26 and La Pequeña Vulcanita 34 and Ouch !

Anyhow ...

When I returned to my prep table I was able to power on the Blue Raven via the Mag Switch without touching the battery.

However, it did not auto-download any flight data.

I shut it down and then did a force-stop on the Blue Raven App on my Android Phone and restarted the Blue Raven and then the Android App and it showed a zero-length file.

Android Screen Shots are below -- there does not appear to be any data.

When I try to [Share .csv] on my phone, I get a message: Exporting low rate file (1/2) and the app hangs.

So my Qs are:

Q1: Is there a way to force an export of the raw data from the Blue Raven via my phone ?

Q2: Is there a new version of the FIP Program for the Blue Raven to download raw datafiles ?

Thanks Adrian !

-- kjh

p.s. I imagine it is too late to save this particular flight data because I was worried that maybe I damaged the Blue Raven so I did a series of ground tests and sims yesterday to make sure the Blue Raven still 'fired' christmas tree lights ( it does ).

I'll check the ignitor later today after work via a Blue Raven Ground Test when the rain is supposed to let up a bit ...

These are the four screen shots of the flight summary after the crash

View attachment 611323View attachment 611324View attachment 611325View attachment 611326

That flight summary screens above are consistent with a false liftoff detection after your flight, which could happen if there were a power interruption at liftoff or landing, or if the Blue Raven saw a high acceleration after a power cycle after your flight.

You mentioned that you turned the Blue Raven back on when you returned to the prep table. Was it off after the flight? The Blue Raven's memory is divided into 2 sections, one for the most recent flight data and the other one gets cleared after a power cycle to make room for more data. The oldest flight data gets erased to make room for a new flight at power-up or after a sim or ground test. If there is a power interruption or another flight is detected while the power is still on, both halves are temporarily full of data. The phone can currently only access the most recent data, but the USB interface can download from either bank. I haven't invested in making the phone interface be able to download from the other bank because it's kind of a corner case and it would complicate the normal interface, so there are higher priorities.

The output settings at the time of the flight are saved along with the flight summary, and are available for saving to your phone or emailing via the "save configuration" button. If you have a flight summary saved from the main part of the flight, that could shed some light on what happened with your main deployment channel.

 

[Adrian A]

That flight summary screens above are consistent with a false liftoff detection after your flight, which could happen if there were a power interruption at liftoff or landing, or if the Blue Raven saw a high acceleration after a power cycle after your flight.

You mentioned that you turned the Blue Raven back on when you returned to the prep table. Was it off after the flight? The Blue Raven's memory is divided into 2 sections, one for the most recent flight data and the other one gets cleared after a power cycle to make room for more data. The oldest flight data gets erased to make room for a new flight at power-up or after a sim or ground test. If there is a power interruption or another flight is detected while the power is still on, both halves are temporarily full of data. The phone can currently only access the most recent data, but the USB interface can download from either bank. I haven't invested in making the phone interface be able to download from the other bank because it's kind of a corner case and it would complicate the normal interface, so there are higher priorities.

The output settings at the time of the flight are saved along with the flight summary, and are available for saving to your phone or emailing via the "save configuration" button. If you have a flight summary saved from the main part of the flight, that could shed some light on what happened with your main deployment channel.

Also, looking at your crash photo, the break in the tube about where your main charge would be makes me ask if you verified that the ematch and charge were still intact after landing?

 

[kjhambrick]

That flight summary screens above are consistent with a false liftoff detection after your flight, which could happen if there were a power interruption at liftoff or landing, or if the Blue Raven saw a high acceleration after a power cycle after your flight.

Thanks for the reply, @Adrian A !

Yes, since I did get drogue ejection at apogee, @manixFan suggested that I lost power due to the jerk of the apogee ejection charge.

Tony has also made quite a few great suggestions over in the Mid Power Rocketry (MPR) sub-forum in my flight report thread: Quest E26 and La Pequeña Vulcanita 34 and Ouch !

There is more info about the site and flight over in the MPR sub-forum.

You mentioned that you turned the Blue Raven back on when you returned to the prep table. Was it off after the flight?

Yes, it was shut down.

I expected ( actually I hoped ) that my phone would re-connect to BlRv-0236 when I walked up to the rocket on the road.

It did not reconnect, but I've had intermittent issues making a blue tooth connection with my Samsung phone so I tried a force-stop of the Blue Raven App and then reconnecting to the Blue Raven on the road where the rocket landed.

I could not hear any beeping, nor could I see the blue mag-switch LED thru the the front-facing barometric pressure port and the Featherweight App did not connect.

Next, I checked the nozzle due to the coning and I saw that there was no nozzle in the aft end of the motor casing.

So I looked around for the nozzle or a pile of nozzle remains and did not see anything around the wreckage.

At that point, I took a GPS reading with my phone, gathered up the parts and walked back to the prep-table by my pickup truck.

When I was back at my table, I was able to restart BlRv-0236 with my magic wand and it immediately connected and showed the summary above and started a download.

The Blue Raven's memory is divided into 2 sections, one for the most recent flight data and the other one gets cleared after a power cycle to make room for more data. The oldest flight data gets erased to make room for a new flight at power-up or after a sim or ground test. If there is a power interruption or another flight is detected while the power is still on, both halves are temporarily full of data. The phone can currently only access the most recent data, but the USB interface can download from either bank. I haven't invested in making the phone interface be able to download from the other bank because it's kind of a corner case and it would complicate the normal interface, so there are higher priorities. The output settings at the time of the flight are saved along with the flight summary, and are available for saving to your phone or emailing via the "save configuration" button.

Yes, that makes sense.

If you have a flight summary saved from the main part of the flight, that could shed some light on what happened with your main deployment channel.

The only data on the phone was what I posted above.

-- kjh

EDIT: bottom of reply cut off ...

 

[kjhambrick]

Also, looking at your crash photo, the break in the tube about where your main charge would be makes me ask if you verified that the ematch and charge were still intact after landing?

Yes, the 7-inch forward section of the airframe, which contains the main chute, snapped off around the perimeter where I drilled countersunk holes for wood screws to attach the AF to the coupler ( design flaw: the position of the screw holes weakened the BT-55 AF right at the top-end of the AV-Bay coupler ).

The main charge was unfired when I recovered the rocket.

The ground test that I posted above in Post #2 - Continued was the same unfired EJG ematch from the main chute section after I removed the 0.6 gram BP charge.

The unfired ematch fired as expected on the ground.

1: I believe I need to re-evaluate the electrical connections in my AV-Bay sled to make sure it can withstand the high shock loading to be expected for such a small rocket.

I am pretty sure now that I lost power because "something" shifted on the sled with the relatively huge 0.6 gram charge.

2: I also need to redesign the mechanical connection system that I use to attach the forward, main chute AF to the AV-Bay coupler so there is a bit more meat above the screw-holes or simply eliminate the screws altogether.

In retrospect. what has worked fine on larger diameter airframes, is an obvious point of failure on a BT-55 ( or smaller ) airframe.

The forward bulkhead of my AV-Bay is a stepped 1/4 inch plywood bulkplate made of two separate 1/8 inch epoxied circular disks with three countersunk wood screw holes at 120 degrees drilled into the interface between the two bulkplates.

Any bending force on the upper airframe will find three holes and the AF will tend to break off at the top bulkplate -- and it did just that when LPV-34 landed hard on a streamer on the asphalt road.

I plan on building 38mm, 29mm and 24mm versions of the same Vulcaninte scale model so it was good that I discovered my mistake now rather than later.

While the 38mm version might be OK, the 29mm and 24mm models would be VERY weak at that point along the airframe.

I am thinking I need to implement something like your ejectable AV-Bay on my future rockets to eliminate the screws altogether ...

And maybe it is time to abandon the classic apogee-aft, main-forward dual deployment model and go with a cable cutter ...

Fortunately, I have a 38mm and a 29mm Featherweight AV-Bay and I recently received a 24mm version from TRF member @Worsaer ( thanks Bill ! ).

Too bad I "screwed" up my AV-Bay -- I am sure the Blue Raven gyro and (x,y) acceleration data would tell me why the rocket coned so badly ( bad fins or off-axis thrust ).

I am planning to reuse the fin can and fly LPV-34 again with my Blue Raven and I'll figure it out.

Thanks again for taking time to reply and letting me rant, Adrian !

-- kjh

OBTW: check out the Mag Switch sticker TRF member @tsmith1315 came up with.

It is on the AV-Bay between the wood screw and the Barometric Pressure port:



SWEET !

You can also see one of the three countersunk brass wood screws just above the mag switch sticker where the upper airframe snapped.