I've just finished the build and will begin early full up integration testing in the next day or so on NTNS-2. This is a highly modified Stinger 64 with APM2. There are really 2 airframes. One is for flight testing, gain tuning, learning a little about APM2. I have to admit that there have been several issues. The two that i know that I have are the flash card slot being a bit less than tight, perhaps some formatting issues -and- the stock GPS lock issue. For my installation this doesn't seem to bother time to 1st fix, but I am loosing lock in flight, dropping satellites. I am NOT using a downlink, have the jumper removed, and power is being applied to the input and output sides with a Castle BEC Pro set at 5.05V. SW version is 2.40. Of course no red wire from the ESC. The GPS is somewhat masked by some wires and the EDF mtr wires run just behind APM down to the fan. It's not ideal for EMI.
Not to worry since this isn't the objective configuration and I just "score" APM when it has lock and the altitude is reasonable. My 100 mph Stinger flight test bird:
Here's a picture from the Stinger HAB build. It's pretty tight inside the bay:
Some of the BOM:
2-Castle BEC Pros (5.3 and 12V)
3-Omega Kapton heaters
1-external relay + helpful external LED
3-Airtronics 94761 servos for flight control
1-analog servo for the sailplane towhook release
APM2
Venus GPS/regulator/logic level converter
SparkFun datalogger
ReplayHD 1080p (heated) and externally powered
4s 5000 mAh battery
airspeed probe and pressure sensor
voltage and current sensor
Airtronics 10ch rcvr, Airtronics SD-10g TX
Very much modified Stinger 64 airframe (the only inexpensive component)
BRB APRS
I'm about 1/2 # lighter than NTNS-1; 1200g Kaymont
Total weight is 3# 2oz vs. the flight test bird at 2# (identical XCG and flight control setups)
Ballast is 2.3oz in the forward bay.
The result:
Testing, SW version catch up/merges, HIL testing with FlightGear/X-Planes, Temperature testing with APM1, duration testing, log testing...camera testing.... to follow.
Comments
Quick Look: NTNS-2 successfully launched and ascended as expected. Peak altitude was ~88k ft. The payload appeared ballistic and impacted fairly close to my ranch, but has not yet been found. I'll post more when the payload is found and the data has been examined. Peak velocities were very high and I belive the chute was not attached at impact. i.e. the balloon burst and the free fall logic worked, or some other combination of anomoly. APRS tracking was nominal and last (direct) measurement was ~1500 ft AGL. LG
The launch time for North Texas Near Space (NTNS-2) is scheduled for 1200Z 8/18/12. The flight may be visible on aprs.fi, but due to the remoteness of the area I'm not expecting great repeater coverage. We are using local tracking as primary. The plan is to launch and land at the same site since trajectory predications only show 17-20 miles to the 100k ft mark. The Call Sign is KA5HND-1.
We plan to chase the payload 1/2 way to the release point to stay in proximity in case there is an off nominal. If all goes well the plane should beat me back to the landing site and loiter for a fairly long time.
Fantastic to see the plans taking shape- keep up the good work!
What is with the use of heaters on this craft?
Rick
That pitot probably won't last long ;-) Lovely looking AF though.