Nova Rebuild - APM Internal Component Placement (Winter 2015)

Methodically going thru aircraft to try to cure WobbleOfDeath. Here are some pics of my work. I think this series of posts will also be a good example of setting up a Nova/CX20 from scratch.

Removed everything from PowerBoard plate and cleaned away old foam-tape.

Since the FC boards are not actually screwed down inside white plastic case, there is some movement. I'm not sure, but I think the PCBs (and attached sensors) can vibrate inside case. I added 2 small pieces of gyro (single-sided and plush) foam-tape to inside of case bottom (not on top where barometer-foam piece is). Seems to work fine.

Zeal gel-tape is highly recommended to mount FC and isolate it from aircraft vibrations. It's not that costly when you consider how far it goes. It seems that while the cheaper alternative "plush gyro mounting tape" also isolates FC from vibrations, it allows the FC to micro-rock-and-sway, which ends up making it an inferior solution ... the Zeal is confirmed to be much better suited for this task. I used 4 cubed 11mm x 11mm pieces as recommended (one in each corner).

FC is again perpendicular to front of aircraft, but now mounted with gyro in exact middle of aircraft (distance between motor shafts). I am mounting in the Default Flight-Controller Orientation (aka AHRS_ORIENTATION,0 ). The RX radio now (foam taped) on it's side, in only other place it will fit.

 

 Accelerometer/Gyro chip (on top PCB, inside FC) should be right under edge of red "O" in NOVA label, specifically market by dot on nylon tie-strap. Another way to measure is ... between Pins 2 & 3, and just past the middle (going in other direction).  

Final placement. Nothing touches each other or any Power-Board component. Everything is loosely tied-down to deter any un-wanted vibrations. Power-Board layout and USB cable further limit possible GPS-Module locations. Specially-cut a gray hard-foam piece to extend platform for GPS-Module, and wedged and foam-tapped in place level. No more RX antenna on outside but one is close to it's old location (but now inside and on opposite side). Near front area is left for FC-RX wiring, and any future upgrades like maybe a SBUS-CPPM converter. Re-mounted 915mhz Telemetry radio back underneath quad where it was before.

Re-mounted Compass/ Magnetometer in a new way with black foam tape and nylon tie-strap (but no hot-glue). Minimum metal screws, and use non-magnetic screw-driver. Simple is good. Red wire is Positive (VCC +3.0v - 3.3v) and Black is GND - verified with meter.



Flight Controller and Radio Wiring

Still using connection method #2 from HobbyKing PnF Setup Video (fairly standard but connecting "Signal Only" as allowed by bridged power rails).

	X8R-RX	APM-FC
RC Cable 1	CH-1 Vertical	CH-1 Vertical
RC Cable 2	CH 2-4 Horizontal (signals only)	CH 2-4 Horizontal (signals only)
RC Cable 3	CH 5-7 Horizontal (signals only)	CH 5-7 (FC Aux 1-3) Horiz
A-Jumper	CH 8	CH 8 (FC Aux 4)
BEC 5v	SBUS

Notes:

• Power from 5v-BEC (on PDB) goes to RX first, and then to Flight Controller. FC really gets its 5volts from CH-1 (3-wire RC-DuPont) cable.
• Vertical connections are the standard way, with standard RC-Cable radio plug (Gnd, Power, and Signal).
• I used "black to the right" when plugging in horizontal "servo-like" RC Cables.
• A-Jumper is a standard (single-pin) 3inch Arduino Jumper cable
• While Channel-Signal-Rail is on FC bottom, it's on X8R's top (opposite).
• By using previously unused SBUS socket for power, frees a standard channel. It shares the same power-rails.
• At this point, I can't even see a reason to need BEC-5v routed to quad's under-carriage connection panel. If need arises in the future, I can just use a RC Y-cable.
• This simple wiring works fine again (for now). When and if I get my gimbal, I will switch over to a FrSky SBUS-to-CPPM Converter wiring setup.

Good pic that someone made.

The white boxes are where you connect Dupont (servo like) RC-Cables. Mine is mostly like this pic. Only difference is that I went ahead and connected CH-6 also to RX (in case needed later). Red VCC and Black GND drawn boxes are just informational.

Another good pic someone drew

This is post 1 of 3 for the rebuild. See next post for APM and radio setup and programming.

Super Nova - Modding for flight

Never thought I would have two of these quads. Like I said, one is just for parts, but I figure ... why not have two brushless quads to mod differently and fly while they are both complete and working. It needs a model name, if for nothing else to differentiate between them in my Radio and also as I post about mods and flights here on the blog. I think I will call this one "Super Nova".

Steps here are not listed in order of importance, but rather in the order of completion. I will just edit this post until finished. Some sub-parts might link to other posts.

I suppose it starts here.

Removed foam-taped Flight-Controller and GPS-Module from Power-Board (PDB).

Added nylon washers to raise PDB about 2mm. Also, removed black foam-tape from bottom of battery compartment. This will help my Turnigy 2700 Lipos to insert and remove easier ( now that they have been exercised and puffed-up a bit) and also give a tad more room for other battery makes. Can't go too high because of other things planned. My two Turnigy lipos fit much better now.

Mounted FC with Zeal so accelerometer is near middle of quad. Cut some holes to route cables through middle (never cared for running them out the back anyway). Since PCB is not actually screwed down, installed single-sided foam tape to prevent any vibration inside case.

This is the bottom of the APM 2.52_v5.0 HobbyKing/Cheerson FC. Connected properly wired custom cable for UART (915mhz Telemetry radio). As posted elsewhere on this blog, Cheerson wired this UART-Socket exactly backwards or reversed. If your radios came with a pre-made cable, most pins will have to be carefully backed-out and moved. Red is +5v power and Black is Ground. As you can see, I did that at the FC side. I had the pin-out, but still verified VCC with a volt-meter at FC first anyway. This is ONLY for the v5.0 version of this FC. I think best to now keep this modified cable mated to this FC.

Installed the Power-Module (details) in ADC port also (black marked on socket is Ground). You can just use XT-60 connectors if you want, but I eventually found them too cumbersome.

I2C port is the existing compass cable. The socket came bent like that, but it ohms-out and solder looks ok so I'm not messing with it.

Connected FrSky X8R with FC with SBus-to-CPPM Converter.

Going to try GPS-Module foam-taped to top of FC. This should basically locate the GPS-Module in "the dome". The FC and GPS-Module are now a unit, and should still be isolated from copter vibrations with Zeal (no part of that unit is touching body).

 

 

 

Installed 3DR 915mhz on bottom-rear of Super-Nova.

 

 

RC Radio Setup and Config:

Using OpenTX-Companion, copied Model#1:"Nova" to Model#2:"Super Nova" and uploaded to Taranis. Radio is now programmed for new model (that was easy).

Flight-Controller (FC) Software Setup and Config in Mission-Planner:

• Connect USB cable from laptop to bottom on Super-Nova
• Start Mission-Planner and click connect to test port and Connect ability.
• Use Auto at first if you don't know com-port and baud rate
• Click Disconnect but leave cable attached
• Upload and Verify Custom firmware file v3.1.5 (from VinnieRC) aka v3.1.5c
• Click Connect
• Reset (Parameters) to Defaults for v3.1.5 and Reboot
• Save initial v3.1.5 params to file
• Click Disconnect in MP

So, this FC originally started on v3.1.2 (stock). No strange beeping now or since I started setup, but the next time I powered-up the Super-Nova, ESCs were beeping constantly. Seems to indicate that ESCs aren't getting a signal because FC can detect that radio is not calibrated yet (getting that message in MP-HUD). Looks like the constant ESC beeping only happens with a combination of ArduCopter v3.1.5 (or higher), ESC revision v1.6 (or higher), and an un-calibrated RC radio.

• Connected other 3DR 915mhz Radio to laptop and click Connect to Super-Nova by radio
• The FC was not "locked up" and there was no problems connecting to it.
• While I started using my 3DR-Radio for the remaining setup steps, you could also choose to use a wired USB cable.
• In MP, calibrated Radio, write params, click Disconnect and power-cycle (reboot) FC.
• Since the radio is already programmed, in addition to the sticks, step thru all the pre-programmed Flight-Modes on the switches. All channels should move (except CH6 which is not assigned to anything on Taranis).
• If ESCs were beeping they should stop now.
• Set Frame Type to X-Y6A
• Click Connect and calibrate the rest of the "Mandatory Hardware" devices. Accelerometer was usual procedure (keep still and perpendiclar). Before starting Compass, I went outside to get basic GPS-Fix for Auto-Dec. Final offsets were -125, 8, -33.

At this point, I'm still running only the ArduCopter v3.1.5 Default Parameters and tuning PIDs.
Some notable Default params are:

COMPASS_EXTERNAL,0
COMPASS_ORIENT,0
FS_BATT_ENABLE,0
FS_GCS_ENABLE,0
FS_GPS_ENABLE,1

Calibrated ESCs (especially since this is a PnF model).

Set my Flight Modes in MP interface (and write/save):
1. Stabilize
2. Loiter
3. Alt-Hold
4. Drift
5. Land
6. Auto
... and in Extended Tuning, CH7=SuperSimple and CH8=RTL
(which I have on dedicated Taranis buttons)

Changed these non-Default parameters:

FLTMODE1,0
FLTMODE2,5
FLTMODE3,2
FLTMODE4,11
FLTMODE5,9
FLTMODE6,3
CH7_OPT,13
CH8_OPT,4

ANGLE_MAX,3000
FS_BATT_VOLTAGE,6
FS_THR_ENABLE,1
GPS_HDOP_GOOD,220
LAND_SPEED,30
LOG_BITMASK,958
MOT_SPIN_ARMED,0
RTL_ALT,2000
THR_MID,530
WP_YAW_BEHAVIOR,1

Tested Fail-Safe with no props installed (passed).

Completed SuperNova assembly.

Armed and carefully did low-throttle "hold by landing gear" test. Also, verify flight modes (passed).

Ready for maiden flight.

If it survives, I'll then work on adding a camera and/or gimbal.

EDIT: Results of maiden flight are here. It flies great.

Nova Rebuild - Flight #10 Test Success (Winter 2015)

Flight test went great. Nova is flying better than ever before.

It hovers great with no WobbleOfDeath (WoD) in Stabilize, Loiter, or Alt-Hold. I had good GPS, so I took it up to about 50 ft. While I have had the Nova for about 6 months now, today's flight session was really just like number 10 or so. See last few posts for my progress on this rebuild.

In summary, the FC is now mounted using Zeal, and placed so that accelerometer/gyro chip is centrally located, and perpendicular to designated axis. Check-out these low vibrations. X/Y are -1 ~ +1 . Z is -12 ~ -8.

Also, X/Y originate at 0 and Z originates at -10 now ... which should be correct if you analyze the mid-points counts of the established Acceptable Ranges of -3/+3 and -15/-5 .

And I think these numbers (generated by calibrations) show just how close the GYRO chip is to "center" or 0.00 OFFSet. Apparently, the prime ACCelerometer CALibration number must be 1.0.

INS_ACCOFFS_X,-0.03946298
INS_ACCOFFS_Y,0.1668732
INS_ACCOFFS_Z,-0.2659737
INS_ACCSCAL_X,0.9984079
INS_ACCSCAL_Y,0.9933763
INS_ACCSCAL_Z,0.9894971
INS_GYROFFS_X,0.02348998
INS_GYROFFS_Y,-0.04615785
INS_GYROFFS_Z,-0.0190655

Finally, on my Nova PnF model ... if I examine where the FC was originally factory mounted (when I first received it), it was much closer to this now determined optimal location. It turns-out, it wasn't as randomly placed as I first thought. While not perfect, it was closer to optimal than the off-set location I originally picked for it (and used for first 10 flights). I think the fact that it was incorrectly mounted non-perpendicular is what threw me off.

I did research this in forums a while back, but ended up getting some inaccurate or maybe just un-conclusive data. This post is the result of my Winter 2015 rebuild (which starts here). I suppose I'll never know if Zeal or exact FC placement is more important than the other, but you can be sure that I plan to install any future FCs in other quads using this "hard learned" lesson and method. Man, talk about details being important. It should also be noted that excessive vibrations had nothing to do with the body/frame being cracked and repaired (that arm is no-more weaker than the rest of body).

A whole Multi-Mode flight (with PropGuards on still). Altitude is graphed on the right.




Damage Evaluation and Repairs

Best I can tell, there is no other damage (no body/frame, internal, or other accessory damage). I will update this post as repairs progress. With gyro reading tilted like that, I expected to find FC dislodged, but no ... the Zeal held and FC is still secure. So, if FC ever gets heavily jolted, it's likely going to need a re-calibration.

Gimbal Repairs:

Using advice from RCGroups user SureShot_ , flattened 45 degree bend in gimbal frame. I used hammer, soft mallet, and anvil. I did not apply any heat. I was afraid it would crack during repairs, but it worked fine. Very soft metal and likely why it bent so easily in the first place. Take your time and make small adjustments until finished.

Gimbal controller looks ok. It was working a bit after crash. Turns out the bent frame was only touching the negative/ground input terminal on the back-side of the board (lucked-out there).

SK-450 frame with PixHawk PixRacer build continued Spring-2019

I recently found my un-finished SK-450. It was to be my first Pixhawk-class aircraft. I think I will work on it for a while, and hopefully get it more flight-worthy .

Since it's the original PixRacer-clone model in the metal-box/case, I decided to just mount it with four 11mm-square pieces of black HobbyKing Zeal-clone material. I then tied it down with a thin nylon-wire-tie. I don't think a "dental-floss tie-down" is quite enough after all. Like the compass, it would be really bad if the FC became detached in flight somehow.

The on-board RC receiver (a FrSky-X8R) is mounted up-front (upside-down, so that top of X8R still ends-up being accessible) .
If you Bind manually, you want:
Mode-4 (D16) FrSky-XJT = CH1-CH16 with Telemetry. FailSafe-Mode is No-Pulses.

On the Taranis, you can setup a new model for the PixRacer-450.
Actually, I just duplicated an APM ArduCopter model (the Nova-360) , and then changed the name and Receiver Number. I noticed I did not even need to re-Bind. You know they are working (actively bound) when RSSI appears on Taranis. Also, the LED on the x8r will now be lit green.

In May-2019, I'm using the current Mission Planner (for Windows) v1.3.66 . I'm using a standard Micro-USB cable.

Upgraded the PixRacer's firmware from ArduCopter v3.5.4 to ArduCopter v3.6.9 (Quad with ChibiOS). Reboot the PixRacer-FC.

• Click Connect. 
• Reset Parameters with Reset to Defaults button. It will reset to v3.6.9 Defaults. Let it Reboot.
• Save initial default v3.6.9 params to file . Start building-up your best params from here.
• If not already Disconnected in MP, do so now.
• Shut-Down MP, disconnect cable, and power cycle aircraft.

On next power-up, ESC might be beeping.  Seems to indicate that ESCs aren't getting a signal because FC can detect that radio is not calibrated yet (getting that message in MP-HUD). Looks like the constant ESC beeping happens with ArduCopter v3.1.x (or higher) and certain versions of ESCs. And, of course, what the APM-FC considers an un-calibrated RC radio.

• Reconnect USB cable, start MP, and click Connect.
• In MP, set your main top-6 or so Flight Modes and Write/Save them
  1. Stabilize
  2. Loiter
  3. Alt-Hold
  4. Drift
  5. Land
  6. Auto
  ... and in Extended Tuning, CH7=SuperSimple and CH8=RTL (each of which I also have on dedicated Taranis buttons).
   
• In MP, calibrate the RC Radio, 
• The sticks obviously, but since the radio is already programmed, step thru all the pre-programmed Taranis Flight-Modes on the switches. All channels should move on MP screen (except CH6 which is not assigned to anything on Taranis).
• Remember that any problems at this point (like only some switches not responding) might be due to incorrect programming on the Taranis radio itself.
• Write params, click Disconnect and power-cycle (reboot) FC.
• If ESCs were beeping before, they should stop now (now that the radio is calibrated).
• Verify or Set Frame Type to X-Y6A (a X-4 quad-config)
• Recall that you have the PixRacer FC mounted in a normal/forward orientation.
• Compass is Forced-External (which also disables any Auto-Detection). Verify proper Compass Yaw-degrees hardware-config settings. Just using one the single external compass for now.
• I would say these are the minimum parameters you want to set or verify before calibrating:

AHRS_ORIENTATION,0
COMPASS_AUTODEC,1

COMPASS_EXTERNAL,2 

COMPASS_ORIENT,0 

COMPASS_PRIMARY,0
COMPASS_USE,1
COMPASS_USE2,0
COMPASS_USE3,0

FRAME_CLASS,1
FRAME_TYPE,1

Mandatory Hardware Devices - Click Connect and calibrate the rest of the mandatory hardware devices. The PixRacer seems to like being rebooted (and/or power-cycled) after each major component is setup and/or calibrated. Save your work and params files as you go.

If all is going OK with your Micro-USB-cable connection, you should be good to try connecting by WiFi instead. Its your choice.
- WiFi connection notes. Connect to copter's WiFi in Windows first. Use UDP in MissionPlanner .

• Accelerometer calibration. 
• Click the button to do the quick Accel calib (just leave level) and then reboot the PixRacer flight-controller (FC).
• After reconnecting, click the other button to do the longer (multi-step) 3D-Accel calibs. Reboot FC again when finished. 
• Follow directions. I find it easier to prop-up against a door because it must be keep still and perpendicular at each step. Use Enter/Return to go to next step.
• It should say Successful at end. 
• It might show the 6 calibration parameters it just created. IIRC, they should all be close-to or between -1.00 and +2.00. I think it might Write them to the FC at the Successful end.
• You can also see them as INS_??????? in params list.
• Return to Full Parameters List and Write them (just in case). You might need to Connect first. Finally, I Save as a File since we made it this far. 
• Compass Calibration
• Due to initial problems getting more than one compass activated and calibrated (with good Offsets) ... I'm just using the one main external compass (up in the GPS/Compass-Combo module) for now. This should also help with compass "variance errors".
• Calibration is pretty self-explanatory. Just start it and then slowly rotate the multi-rotor aircraft on each of its 3 main axis (likely a couple of times each). If done properly, it should progress and complete in good time. 
• It would not hurt to do this outside (like at least the back-yard). Not only would this eliminate any possible building-structure interference, 
• but also ... you can do it while Auto-Declination and GPS are active. 
• Note that after it has been done successfully, it SHOULD NOT need to be done again, any time soon. 

Optional Hardware Devices - Click Connect and calibrate any optionally-installed hardware devices. The PixRacer seems to like being rebooted (and/or power-cycled) after each major component is setup and/or calibrated. Save your work and params files as you go.

Battery Monitor or Power Module (standard APM-style PM)
- This is with a Turnigy 11.1v 2700mah 3s 20-30c LiPo battery
Monitor: 4: Analog Voltage & Current               Battery Capacity: 2700
Sensor 0:Other
APM Ver: 4:The Cube or Pixhawk
Power Module Calibration
1. Measured Battery Voltage: 11.6v (measure and enter yours here)
3. Voltage Divider: 10.82
6.  Amperes Per Volt: 19.1
For this PixRacer Flight Controller, my relevant parameters were:
BATT_MONITOR,4
BATT_CURR_PIN,3
BATT_VOLT_PIN,2

Reboot, and it should be working and now appearing in HUD.

Also, verify or change these core parameters     
(this first set should also be Pixhawk defaults):

ANGLE_MAX,4500
GPS_HDOP_GOOD,140
LAND_SPEED,50
LOG_BITMASK,176125       (Most logs, including IMU for vibrations )

RTL_ALT,2500
FS_GCS_ENABLE,0
FS_THR_ENABLE,1                (Very important)
FS_THR_VALUE,950              (Adjust for your calibrated radio throttle)

Also DONE :
- Install FAA ID-Tag sticker

ToDo:
- Calibrate ESCs (a good time, since new FC in new aircraft).
- More Arming and motor-run tests.
-     -    Already noticed GPS-Module working really well in shielded areas.
- Calibrate compass again, outside this time.
- Test Fail-Safes and RTL
- Setup Taranis "Flight Time" telemetry Page for this model
- Install props (mark type and direction)
- Tethered flight test.
- Maiden flight
-     -     Stabilize (manual mode) and hopefully some GPS-Modes testing as well.

Nova repairs and updates

Here are the repairs and updates done to the Nova #2. The post will be updated until this aircraft is returned-to-flight.

Current known issues:
1. Repair or replace bad motor and/or ESC in bad set
   - Done here ... it was the ESC.
2. Repair cracked puck and do epoxy mod to reinforce.
   - Done like this
3. Check GPS-module cable. I lost GPS for 5 mins during field testing (and it didn't appear to be an GPS-Almanac update).
    - I lightly filed and cleaned up black corrosion from pins on both the compass and GPS-Module (like this). Re-used existing cables, but did clean them with (plastic-safe) contact cleaner.
4. My old Turnigy 2700mah Lipos have puffed-up to much too fit inside any more.
    - While I had it open, I raised PDB from 2mm to 6mm. I also had to move some things to keep them just barely away from top white body-shell.

Here is the final internal config (right before closing it up). Examine closely to see how I lowered the profile. Obviously, the GPS-Module was moved to be closer to tallest part of dome. Also, I had to remove part of USB cable wire insulation so it would not touch side of shell inside. APM_252 FC should still be "floating" on Zeal (which was the main objective).

Full Calibration results:
No problems with Radio, ESCs, or compass (offsets are now -31, -74, -41).

Having trouble with Accelerometer Calibration in MissionPlanner v1.3.39 and v1.3.41 . I'm currently investigating issue with the more knowledgeable forum members. At first I thought it was MP, but I recently found out that it works fine with a PixHawk v2.4.8 ... so it must be something with this APM_v252 FC or APM in general. It does seem to work thru Terminal though, which is even more puzzling.

Turnigy SK-450 PnF quad - The latest addition to the hanger

Here's the latest addition to the hanger. I caught it on sale at HobbyKing for around $100 (and with Black-Friday free shipping from USA warehouse) and could not refuse. Lets call it a birthday present :)

I plan to figure-out KK-2.x FC just enough to test the ESCs and motors. I've got some spare FrSky X8R RX's, so I'll drop one of those in there. However, I'm pretty sure it's getting a PixRacer and GPS pretty soon. I've be wanting to install the spare PixRacer in something for a while now. Actually, wanting to get a PixHawk-anything in the air :)

It's good to be back "in the hobby" more these days, but I need to stay away from hobby websites :)

Either I've been busy or the weather was bad, so I'm still looking for a good time to go fly the rebuilt Nova.

EDIT 12-2017
PixRacer Install

I got the PixRacer and Power-Module installed. Just using the single external Beitian compass/gps unit. FrSky-X8R fits nice up-front. Taranis programming was mostly the same as Nova/CX20. In fact, I just copied over the Nova model to the SK-450 model.

After clearing/working some strange Pre-Arm errors in Mission-Planner:
- Check Firmware - Already had ArduCopter v3.5.4. Flashed to ArduPlane and back-again
- Check FRAME-CLASS - Was X4, but switched it back-and-forth. Saved and Reboot
- Check 3D Accel - Calibrated it again. I guess required after major firmware switching
- Check Compass - Set to use single external one and Calibrated
- Check RC Roll not Configured - Re-Calibrated Radio (all sticks and switches)
- Check FS_THR_VALUE - Radio throttle stick goes to 982. Had to lower from 975 to 950.


I finally got the PixRacer Armed and spun the Motors for the first time. The ESCs also had to be calibrated.

It came together real fast. Before maiden flight:
- PixRacer needs to be mounted more permanently ( I found my stash of Zeal gel-pad).
- More settings in MissionPlanner.
- Need to setup my first PixHawk (PixRacer) with my preferred APM params equivalents
- Wiring and antenna-mounting will need some clean-up

Notes:
WiFi AP is AI-THINKER_code

Maintenance Procedures

I've done a couple more gimbal test flights ... Where to start? How about I post symptom and then action.

Vibrations:
Apparently, the gimbal's extra 185g weight really stresses my little 350-class Nova. It's now approaching it's max. payload weight, so aircraft setup has to be extra good. These new aircraft vibrations were causing gimbal vibrations as well as general quad stability issues (as FC deals with them). It seems the brass-looking metal inserts for the main body screws were not actually fully attached to upper body shell any more. While the screw originally did tighten fully (didn't spin in plastic), the inserts could slide vertically. This was preventing them from doing their job properly. Since body is also frame, this was causing major arm flexing. To repair, insert a screw part-ways and tug to test all of them. I used super-glue and re-glued all 4 main ones (on arms, closest to landing-gear). The rest were ok at this time. If you ever see one that has backed-out ... don't just pop it back in ... it must be re-glued.

While I thought it was the gimbals weight that was originally causing the quad to fly so poorly (and for the motors to sound so labored and stressed), I think this was instead the root cause. This whole "searching for better PIDs quest" might be un-necessary.

Altitude drift:
Altitude holding worse than before. Put packing tape over 80% of new barometer-hole mod. Barometer seems more normal now.

Nova FC parameters:
I got some new (just slightly tweaked) PIDs from Skywarka on RCGroups. With the extra 185g gimbal weight, these seem to work better. See bottom of AC3.1.5 upgrade post for current ones. THR_MID=670 is finally determined and tests good at this weight.

Gimbal dampening:
Shoved memory-foam ear-plugs into gimbals dampening balls. Installed Mobius (and holder-tray) on gimbal arm flat with two 1cm strips of Zeal (instead of nylon 1/4" screw and washer). For extra security, I've tried a small elastic band and/or a tighter nylon tie-strap. End result is more Mobius contact surface area with gimbal arm, and seems to have fixed the "gimbal buzzing".

Gimbal Parameters:
I'm back to using my originally posted SimpleBGC parameters. Apparently, the "whole video shot" vibrations, occasional "jello", and buzzing were all minor hardware crafting problems.

Mobius:
Changed Primary recording mode to 1080p/30fps Narrow. Will decrease "fish-eye effect" when camera is pointed down. While the end-effect looks like a zoom, it's actually a pixel-matched 1080p recording from middle of lens. I also tried 720p/60fps/Narrow ... while it is smoother, it's not as sharp when played back on 1080p monitor. I have it setup as Secondary.

Tower/DP3
While I think the dev's algorithm is set a bit too aggressively, I had Tower's "Imminent ground Collision Warning" go off a couple of times (still getting used to this gimbaled flying turkey). I've never heard it before so I didn't even know what it was (or if it was coming from Tower or the Taranis). It just sounds like "alternating bells and alarming". I would have preferred a voice-alert (maybe something like "PULL-UP"). A red "alert bar" appears across top of screen, but it's not like this is usually a good time to be looking at tablet.

Eachine Blade 185 - RX upgrade and GPS install

I needed the FrSky-X6R for another project, so I installed a smaller FrSky X4R-SB in the EB-185. The X6R was really just for testing anyway (but I did fly it that way several times). I think the X4R-SB (also using SBus) is a better match. I mounted it with a square of black HobbyKing Zeal-clone. The blueish silicone tubing is just long enough to contain the 2 antenaas. It's wire-tied to the edges but away from spinning props.

Like before, connect cable from EB-185 PCB to the RX. That's the supplied cable with the little white 3-pin connector (SBus w/ Power) to FrSky X4R-SB using the black DuPont-RC plug on the other end.

On the Taranis:
Mode: D16
Channel Range: CH1-16
Receiver No: 03

I bound it in D16 Mode with Telemetry (CH1-3 SBus). That is the "No Jumper required Bind" and is comparable to the similar Mode-5 (D16) on the X6R/X8R.

Hold-down the F/S button on X4R-SB and power-it-up (plug-in EB-185 battery). IIRC, it's LED will be red. On Taranis' (Model-03) program screen, click Bind. Power-cycle EB-185. LED on X4R-SB should now be steady green (showing it's Bound). The EB-185 should also stop beeping now.

I also installed a GPS-unit I ordered for it a while back. They said it was for Naze32 (Rev6 10DoF) and had the proper connector already to PnP on this EB-185. I thought I would try it first on the low-deck where it's protected and there is plenty of room. I thought it might get a good-enough signal from the sides and even the top a bit. If not, I'll create and install a little platform for it behind the battery.

I plan to get back into CleanFlight and add some new Flight Modes and see what's up with the GPS features. I'll add to this post later if I come across anything interesting.

The Eachine Blade 185 is still flying good. My skid-plate mod seems to be keeping the VTX and its all-in-one PCB from getting damaged.