DX20 with Dragon Link Mount

I spent some time the other day and set up the DX20 for the Sabre. Now I have pan and tilt on sliders, which will be really nice for "looking around" and just enjoying the FPV experience.

Now with that task done, I had to figure out a way to mount the Dragon Link transmitter module to the DX20. It was a challenge because of the dual antenna orientation on the DX20. The horizontal one is also a carrying handle, with a center pylon, which was the main reason it was tricky to find a suitable mounting location. I also needed to leave space for the Dragon Link power battery.

The result isn't pretty, but it's functional, and very quick and easy to install.

The final configuration. Front view.

The final configuration. Rear view.
The single dowel is used to attach rubber bands to the radio's
horizontal antenna, which holds the entire assembly on. The same
dowel is where the single rubber band also holds the Dragon Link transmitter.

The Velcro is where the battery attaches. The small square opening
is where the vertical antenna goes. That's the main mounting interface.
Then the rubber bands stabilize the assembly against the horizontal antenna.

 

Battery mounted.

New Radio: Spektrum DX20

I picked up my new radio that I'm hoping and assuming will be sufficient for many years (decades?). The Spektrum DX20 is Spektrum's "flagship" radio, and is packed full of useful features. It also came with a really nice carrying case to protect it.

For me currently, the most notable change in how I fly is that I now have enough channels to use my pan/tilt setup on the Sabre. In addition to that, I will be able to program more flight modes into the mode switches, and I will have a gain knob, to change the Vector's overall responsiveness quickly while flying. Another minor benefit is that I will be able to program the nose wheel steering on a separate channel so I can lower its sensitivity.

I'm excited to get to work on programming the radio.

There's still a screen protector to tear off. I have a
quality custom screen protector to install.

The carrying case. It actually includes space for two transmitters.

New FPV Headset and DVR

Headplay SE

I've been using a cheap (like the cheapest you can buy) FPV headset since I started FPV over 2 years ago. It was the HobbyKing Quanum set, which came as a complete bundle with the video transmitter and receiver as well. While it works reliably, it is bulky, uncomfortable, and the screen is low resolution. I had upgraded the video receiver which helped, but it's still kind of bulky and heavy for what it is.

I now have upgraded from that set in a BIG way (literally). I bought the Range Video product called Headplay SE. This is a new and improved version of their popular Headplay HD. It's another "head box" style display, as opposed to a goggle. I prefer the wider, more immersive feel of the large 7" screen, compared to a far-away "movie theater" feel of the goggle displays.

It comes with an integrated 40 channel 5.8 GHz video receiver.

Anyway, it came on Saturday and I can't wait to try it out. I soldered up a new Deans plug and it powers up fine. The unit itself is HUGE. It makes the Quanum set look small by comparison.

However, it is extremely comfortable. It features 1/2" thick, high quality padding everywhere that touches the face. Also, the battery to power it mounts to the back of the head, instead of on top, which helps the weight distribution dramatically compared to the Quanum set. The Headplay even came with a nice bag to transport it in.

Headplay Bag

Face Seal

Another huge improvement with the Headplay is that it came with a DVR (digital video recorder). This means that from now on, I will be recording the OSD to a micro SD card for all flights. This is a convenient way to review what went wrong in a flight if something does go wrong. The DVR is mounted on top of the unit itself, and the wiring is integrated with the power wire harness which runs back to the battery.

DVR

Finwing Sabre Flights 41, 42, 43

Yesterday was a great day with the Sabre. Flights 41 and 42 were done with the 16,000 mAh battery and flight 43 was with the 10,000 mAh battery. Winds were less than 5 mph and it was smooth.

As for the camera mount, mounting it on top of the FPV camera like I posted about here didn't work. It added vibration and did not reduce the "jello" much. However, what did help a lot was to isolate the camera by taping it to a rolled up paper towel cushion, and also taping some quarters to the camera to add more mass. The videos are much better now, and are enjoyable to watch.

I also tried using the telemetry setup that I posted about here. It wasn't very successful. The data would update for a few seconds and then freeze and ultimately lose connection altogether. I'm not sure if it was a Bluetooth connection issue or a telemetry range issue, or instability of the software. After about 10 minutes of messing with it I abandoned it to enjoy the flying.

In flight 43, I did my first FPV landing with the Sabre. That was exciting. It wasn't a perfect landing, but it wasn't too bad.

Here are some videos from onboard:

Onboard Video, Flight 41

Onboard Video, Flight 42

Onboard Video, Flight 43

A couple nice views of the Erie Canal.

Sabre with Telemetry

Part of the Dragon Link Advanced UHF control system is that it includes a telemetry capability. I recently configured this and have it working for the first time. I have not flown with it yet, but it seems to work properly while on the work bench. The range for the telemetry isn't as good as the radio signal itself, but time will tell how good it actually is.

It took a few hours to follow the Dragon Link instructions to activate the telemetry and it was relatively straightforward.

Here's how it works:

• In the air:
• The Vector flight controller and Dragon Link micro receiver are wired together with specific inputs and both must be configured properly communicate telemetry
• The Dragon Link micro receiver transmits the Vector data back to the Dragon Link transmitter on the ground
• On the ground:
• The Dragon Link transmitter receivers the telemetry data from the receiver in the airplane
• The Dragon Link transmitter communicates the telemetry via Bluetooth (or USB) to an App called Mission Planner
• Mission Planner (on my laptop) connects to receive the telemetry signal and provide live data for critical flight parameters, (GPS location with live map overlay, speed, altitude, current, RSSI)

Having this data available is an extra safety layer just in case the plane goes down or the FPV system fails in flight. Windows 10 has a built in way to record the screen, so I will use that to record the telemetry for each flight. In theory, it would allow me to have a good idea of where the plane is if it goes down, or at least where it was shortly prior to that.

The new wiring is the black and orange wire on the right,
which runs down to the bottom of the receiver on the left.

Here's a sample of what Mission Planner looks like. When communicating
 to the aircraft, it shows the aircraft's path and position on the map.

Sabre, New Mounting for the Mobius

So far, in the 38 flights I've done with the Sabre, the one consistent issue is that every HD video recorded with the Mobius camera (same camera as on my rockets) shows significant "jello." This is also called rolling shutter effect, and is a result of how the camera records line by line (rolling shutter), combined with vibration in the plane. It appears to be a function of the throttle setting, so I'm assuming that the vibration is related to the motor and propeller.

All videos so far except for flight 38 had the camera taped to the nose, in front of the pan/tilt mechanism.

Mobius Camera Taped to Fuselage

I've tried a piece 1/4" thick foam under the camera without success. I've also tried re-balancing the propeller, shimming the propeller to fit the shaft better, and trying a replacement propeller, all without success.

Flight 38 had the camera taped to the wing. This also didn't help. After doing some reading, I found out that you're supposed to balance the propeller blades and the propeller hub. I never had balanced the hub before, so I ordered a better prop balancer (Dubro #499) and gave that a try (I haven't flown since).

At the same time as the prop re-balance, I also mounted the Mobius on the pan/tilt mechanism. I used the mount that the Mobius came with for a tripod, and used the 1/4-20 insert to mount a piece of 1/4-20 nylon bolt. That's slid into the paper tube that's glued to the camera mounting plate. The front end of the Mobius is secured with a Velcro strap around the FPV camera.

I'm hoping this will correct the jello by helping to isolate the camera from the airframe. At the same time, it will allow the HD video to follow the FPV pan/tilt while I'm "looking around" while flying.

Finwing Sabre Performance and Current Equipment

Latest Update: 1/9/18. The latest updates to this post are in bold.
Old (obsolete) data is in italics.

With the introduction of the Sabre complete, I thought I would share the current setup and configuration of the plane.

Currently Configured Performance:

• Updated 1/9/18: All up weight: 7.65 lbs to 8.73 lbs with 1.3 GHz video system Link to update
• Maximum airspeed: 55 mph (full throttle)
• Maximum amps: 50 Amps 
• Typical Cruise airspeed: 30 - 35 mph
• Cruise amps: 11 - 12 Amps
• Stall airspeed: 25 - 26 mph
• Maximum climb rate: >20 feet per sec
• Maximum cumulative distance in one charge: 43 miles 
• Updated 10/30/17: 44 miles (on 16,000 mAh battery)
• Maximum duration achieved (single flight): 75 minutes (on 16,000 mAh battery)

Currently Configured Equipment:

• Electronics
• Servos (not including pan/tilt)
• 4X 23 gram metal gear Finwing servos (2 ailerons, 1 nose gear steering, 1 elevator)
• 1X Finwing 9 gram servo (rudder)
• 2X Hobby King 9 gram servos (flaps)
• ESC
• Finwing 60 Amp, 4s to 6s Lipo, no BEC
• Motor
• Finwing brushless outrunner M2820(3542)
• BEC
• Finwing BEC, 2s to 6s Lipo (powers the receiver and servos)
• Receiver
• Dragon Link 12 channel micro receiver (with stock antenna)
• Flight Controller
• Eagle Tree Vector
• Pitot Tube expansion kit (for airspeed)
• FPV Gear
• Camera
• Runcam PZ0420H CCD
• Updated 10/30/17: Runcam Eagle 2 Link to Update
• Updated 12/6/17: Onboard Microphone
• Range Video RVmic with Volume Control Link to Update
• OSD
• Built in to the Eagle Tree Vector flight controller
• Video Transmitter
• Drak 600 mW 5.8GHz
• Updated 12/6/17: ReadymadeRC 400mW 1.3 GHz Link to Update 
• Video Transmitter Antenna
• Updated 10/30/17: Varied Antennas, Link to Update
• Updated 1/9/18: TrueRC 1.3 GHz Singularity, OR VAS Airblade 1.3 GHz
• Pan/ Tilt
• ReadyMadeRC Pan/Tilt Kit
• 2 Hitec HS-65HB servos
• Updated 10/30/17: Finwing Sabre included pan/tilt Link to Update
• Hardware
• Stock pushrods and control horns
• Stock nylon wing mounting bolts and wing nuts
• Added magnets to the centers of the wing halves to help hold the wing as one piece during assembly
• Stock main landing gear strut
• Upgraded nose gear (used Dubro strut)
• Stock wheels
• Updated 11/15/17: Dubro Super Lites: 3" Nose, 2.75" mains Link to Update
• Propeller
• APCe 11x5.5
• Flight Batteries
• 4s 10,000 mAh 15C Turnigy Graphene
• Provides 50 minute flight times (possibly more)
• 4s 16,000 mAh 10C Multistar
• Provides 75 minute flight times (possibly more)
• HD Camera
• Mobius ActionCam HD
• Updated 10/30/17: Mounted to Pan/Tilt Link to Update
• Updated 1/9/18: GoPro Session 5 Link to update
• Ground Equipment Link to most up to date
• FPV Viewer
• Hobby King DIY headset (can use as backup)
• Updated 9/19/17, Headplay SE: New Headset
• Updated 12/6/17: Battery for Headset Link to Update
• Video Receiver
• ReadyMadeRC Mantis 5.8 GHz (can use as backup)
• Updated 9/19/17, Headplay SE: New Headset
• Updated 12/6/17: GetFPV 1.2/1.3 GHz Receiver V2 Link to Update
• Video Receiver Antenna
• Basic circular polarized
• Updated 10/30/17, Varied, Link to Update
• Updated 1/9/18: VAS Airblade 1.3 GHz and/or VAS Crosshair 1.3 GHz Link to update (1 of 2)  Link to update (2 of 2)
• Transmitter (Radio)
• Borrowed Spektrum DX6
• Updated Link to DX20 Introduction
• UHF Transmitter
• Dragon Link V3 Slim (with stock antenna) Updated 12/6/17: with VAS 1.3 GHz Notch Filter Link to Update)
• 2s 800 mAh battery for UHF transmitter power
• Update: Link to Repeater Ground Station Description
• Updated 10/9/17: Link to Update
• Updated 10/30/17: Link to Update
• Updated 12/6/17: Ground Station Battery
• Turnigy 4S 5,000 mAh (for 1.3 GHz video ground station)
• Updated 1/9/18: Turnigy 2S 5,000 mAh (for control repeater)

Updated 12/6/17: A few items are shown below which do not have their own posts.

Dragon Link Receiver Antenna, Mounted to Vertical Stabilizer

Eagle Tree Vector Flight Controller and Dragon Link Micro 12 Channel Receiver
(There is a LOT more wiring going on now that the plane is 12 channels and has a microphone.)

Stock Nose Gear After a Good Landing on Grass

Custom Nose Gear, Made with Dubro Strut

Long Range First Person View (FPV) Plane Introduction

I've been working on a new plane since early July 2017. It's the Finwing Sabre that I bought from ReadyMadeRC as a dedicated long range first person view (FPV) plane. As of the time of this first post, the plane has 38 flights on it (all successful). The plane has a wingspan of 75", is made with EPO foam, and weighs 7 to 8+ pounds flying weight (highly dependent on battery).

Youtube video link:
Finwing Sabre Onboard Videos Playlist

My intent was to slowly expand my FPV experience from typical, simple, backyard flying with my Parkzone Sport Cub, to a sophisticated long range setup.

This means the plane will be capable of long range radio performance, long range FPV video, and have a flight controller with on-screen-display (OSD). The OSD provides the live FPV view with all of the pertinent data regarding the airplane's location, speed, altitude, battery voltage, etc.

The scope and some goals when I started this ongoing project were as follows:

• Plane must be capable of 20 miles and back (40 mile round trip)
• Plane must have a pan and tilt setup on at least the FPV camera
• Plane must carry at least one HD camera
• Use the Eagle Tree Vector flight controller and OSD
• Use the pitot tube expansion kit for the Vector flight controller (for airspeed)
• Use Dragon Link Advanced UHF long range radio and telemetry system
• Use 1.3 GHz FPV gear (for range), rather than the 5.8 GHz gear
• Build a proper ground station for the receiving end of the FPV video signal

Here are some photos of the plane. I will follow up with more posts to detail the setup and progress with regard to the scope of the above items.

Sabre when it was first completed, prior to maiden flight.

How it looks decorated, with the color applied with Monokote sticker sheets.

In Flight