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BayouRat

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Brand new Raven did not fire the apogee charge. I had good continuity at launch and after landing. Ematch worked when tested after the flight. I'm attaching the data file. Maybe some one can help figure it out because I'm scratching my head.

View attachment GoDevil54-K250-9-2017.FIPa
 

BayouRat

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Checked setting in program. Only changed the main to deploy at 1,200' (1,184' actual)
Everything looked good. I have 2 other Ravens and I've flown them for years. I've never had a problem before. Maybe this one is defective?
 

dvdsnyd

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How did you test the charge after the flight? Did you use the same battery that flew?
 

markjos

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Looking at the data file - I see that the Apogee voltage bounced up and down a couple of times, then stayed at 0V shortly after motor burnout (between 5.5-7.0 seconds into the data). At the risk of being vague, I'll hazard a guess that vibration or Gs opened or shorted something in the apogee charge circuit.

I'm interested to see what others think of this. How's the rocket and recovery gear?

Mark
 

cvanc

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Looking at the data file - I see that the Apogee voltage bounced up and down a couple of times, then stayed at 0V shortly after motor burnout (between 5.5-7.0 seconds into the data). At the risk of being vague, I'll hazard a guess that vibration or Gs opened or shorted something in the apogee charge circuit.
^^^This.^^^

Looks like the connection to the apogee ematch failed during flight (~7 seconds), and got re-established much later (~68 seconds).

Pictures of your setup might help... good luck figuring it out.
 

BayouRat

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^^^This.^^^

Looks like the connection to the apogee ematch failed during flight (~7 seconds), and got re-established much later (~68 seconds).

Pictures of your setup might help... good luck figuring it out.
I thought that too. Everything is soldered. Nothing can bounce except internally in a defective altimeter. That's what everything is pointing to.
 

Len B

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Look at the current draw graph. That looks really weird. I have very little experience with the Raven. One flight and a bad result. I don't want to bring my results into this thread.
Is that current draw graph normal though?
 

OverTheTop

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Be careful if you are soldering the 9V batteries, Duracell or otherwise. The connection between the cell stack internally and the press studs on top is only done by a rivet. When the studs are soldered the plastic top spacer flows a bit and takes pressure (needed for contact) off the riveted joint. I love soldering for reliability, but for 9V battery connections I would go the regular clip every time (but held on with positive retention of some sort!).

Also, not such a problem these days, is that the cells used to be just a stack of button cells very lightly compressed by the housing. A bit of accel or jiggling on those could give you an open battery.

Cut open one of the same batteries you are using to see what the construction is like.

The supercap on the Ravens does a good job of holding up the supply for quite a while when the battery is disconnected. Depending on the disconnect time you may not even see the main supply fluctuate. I can't remember the details of how all that works together and what is available on the graphs.
 

BayouRat

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Look at the current draw graph. That looks really weird. I have very little experience with the Raven. One flight and a bad result. I don't want to bring my results into this thread.
Is that current draw graph normal though?
Compare it to this flight that everything worked. Looks the same to me. Also the voltage drop. Just the voltage drop happens when the apogee change fires. On the failed flight the voltage drop happens before apogee.

View attachment MaxAttackN1000-Sept2017.FIPa
 

BayouRat

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Be careful if you are soldering the 9V batteries, Duracell or otherwise. The connection between the cell stack internally and the press studs on top is only done by a rivet. When the studs are soldered the plastic top spacer flows a bit and takes pressure (needed for contact) off the riveted joint. I love soldering for reliability, but for 9V battery connections I would go the regular clip every time (but held on with positive retention of some sort!).

Also, not such a problem these days, is that the cells used to be just a stack of button cells very lightly compressed by the housing. A bit of accel or jiggling on those could give you an open battery.

Cut open one of the same batteries you are using to see what the construction is like.

The supercap on the Ravens does a good job of holding up the supply for quite a while when the battery is disconnected. Depending on the disconnect time you may not even see the main supply fluctuate. I can't remember the details of how all that works together and what is available on the graphs.
Soldering was done with a heat sink and the battery was G tested before and after the fight. it passed all test.
 

BayouRat

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Official word from Adreian: Loose connection in apogee wiring or ematch. The Raven lost continuity on the apogee channel at motor burn out then reacquired continuity when the main fired and subsequent high G event.
Solution: I'll fly this rocket on another altimeter and fly that suspect Raven in another rocket as a backup till it proves itself. Thankfully at this stage of the game I have multiples of each. But my goal was to keep one or two flight computers in each rocket.
 

dixontj93060

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What type of e-match? I have had some crazy things go on with the Quest G-whatevers with both PerfectFlite and Raven alts.

Sent from my Moto G (5) Plus using Rocketry Forum mobile app
 

OverTheTop

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Soldering was done with a heat sink and the battery was G tested before and after the fight. it passed all test.
You seem to have ticked all the boxes there, but I still wouldn't do it. YMMV.
 

ksaves2

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Official word from Adreian: Loose connection in apogee wiring or ematch. The Raven lost continuity on the apogee channel at motor burn out then reacquired continuity when the main fired and subsequent high G event.
Solution: I'll fly this rocket on another altimeter and fly that suspect Raven in another rocket as a backup till it proves itself. Thankfully at this stage of the game I have multiples of each. But my goal was to keep one or two flight computers in each rocket.
Reset to stock configuration, do the baro deployment for apogee, select your main opening altitude. Could do the calibration process for the accelerometer but if using baro for deployments this might not be necessary. Might help if your looking at data off the accel though. Put ematches on the main and apogee channels and do a sacrificial test.

When done, fly in a beater rocket with a motor combo that's not going to send it too high. If it works, you're in business.

I will share I bought a new Raven one time and decided to use a carpenter's clamp to hold to large capacitor to the board while the epoxy dries. Clamp slipped, smacked the board and the altimeter function became intermittent. What I mean is have it running and give the board the tiniest of twist or torsion and it reset! Some component got whacked when the clamp slipped. Looking on with a high magnification
scanner revealed nothing that could be easily seen too. $155.00 down the toilet.

That said, I have an old Parrot altimeter that survived a ballistic flight and after replacing the onboard battery and testing it out, it technically looks good.
Flight was human error when one arm of the apogee ematch was incorrectly connected (ie. missed the hole). Main blew but harness broke. Charge tested 18 months later after it was returned to me and blew. (Landowner found it in 5 days so it didn't sit out in the field for that long and escaped the weather.)

Nonetheless, if I fly it, it's going into an armored "beater" rocket. Kurt
 
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Adrian A

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You seem to have ticked all the boxes there, but I still wouldn't do it. YMMV.
The data shows that the intermittent connection was just in the apogee charge. The battery voltage looks solid throughout, so it looks like his battery soldering worked.
 

BayouRat

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The data shows that the intermittent connection was just in the apogee charge. The battery voltage looks solid throughout, so it looks like his battery soldering worked.
Thanks for the great support and fast response. I still haven't found what caused the open condition. I may just rewire the whole apogee side to eliminate any possibility of wiring being an issue. It may have been at the screw terminal or the ematch also. The rocket will fly again in a couple of weeks it's just 3" shorter now because of the zipper and it ripped the eye bolt out of the nose cone bulkhead.
 

Len B

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Compare it to this flight that everything worked. Looks the same to me. Also the voltage drop. Just the voltage drop happens when the apogee change fires. On the failed flight the voltage drop happens before apogee.
You're right. It looks exactly the same. Huh. I guess since the range is very small, it just looks dramatic but isn't so bad. Thanks!
 
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