Finally I've got all systems working. The combination of the telemetry modem and GPS module gave me a lot of headaches. The solution proved to be a separate UBEC for the modem and moving that UBEC as far away from the other electronics as possible.
This plane is fully decked with:
- Downward facing gopro/mapir
- 433 telemetry
- D4R-II radio
- Navio2
- I2c airspeed
- I2C sonar
- Flaps
- A laser cut housing for all electronics that slides inside and is attached with a couple of screws.
- Half lambda dipole antenna embedded in the tail.
What do you think? Ideas for improvement? What are more bulletproof (less noisy) telemtry setups?
Replies
ok, I understand now why you put the air speed sensor on the side. Yeah, let me know flight time, please.
I am going to use 2 x 3S @ 3000 maH batteries next time. Let's see what times I get out of it. I will probably upgrade to 10,000 maH later. Are you putting the batteries near the nose or right below the wing to maintain existing Center of Gravity? I initially put the batteries near the nose (tons of on air trimming was needed for sure) and it's funny during my 2nd flight my 4S battery got loose inside the plane. lol..it was rolling around inside the fuselage. It was almost impossible to control the plane but some how, God knows how I landed the plane on a commercial street next to my flying field and ran to pick it up before it would get run down by the incoming cars :)
I am going to use pixhawk as the FC. I have never used pixhawk or APM on fixed wing plane before..lol this should be a good learning experience. Your idea of RTL sounds good, I will give it shot to determine max flight time as well.
My main goal is to fly as far away as possible and totally relying on 80KM Telemetry and video Transmission back to the ground station via 4G/5G LTE backhaul. So I am going to be out in the wilderness, but first all checks need to be done prior to attempting such a risky flight plan :) No chance of recovering the plane for sure.
I wanted the airspeed sensor to be protected from nose and bush landings. The tube is quite fragile. That's why I put it under the wing.
I haven't tested the batteries to their full limit yet. I'm planning to put the plane in RTL and get some coffee while watching the batteries over the telemetry to see how much time I get out of them...
I also removed the landing gear to save weight. I hand launch and belly land.
I found the plane also shaky in the air, but I assumed it was the wind.
iSkyMaster said:
The first test flight, it was not very smooth. Although the wing span is pretty big it really doesn't fly very smoothly.
I have also cover coated (mono coat) the wings for stability. May be at high altitudes it will become more stable.
What is the flight time you got out of 2 x 10,000 maH batteries so far?
By the way, I noticed how you mounted the air speed sensor. I am assuming you know that at the front of the nose there are two holes designed to accommodate air speed sensor.
I'm flying 2x10000 mah 3s.
Flies just fine.
Why do you think it's not the best plane?
I am using Dragon Link V3 on my Ranger. 40 to 50 KM Telemetry support. I think I bought the last stock :)
Also, you can consider 100 km range ad on TX and RX from SCHERRER UHF Military grade system.
http://www.tslrs.com/
What is your battery size? I am using 4S, 5200 mAH. I have not done the long range testing yet but flew the plane. Not the best plane in the world but will see.
For what it is worth ULRS has worked well for me (after a few recent issues). I do wish Benoit would open it up though...but it does not affect me as I have no wish to play with that firmware.
Telemetry has been good and ditto bluetooth. Not sure about that Wolfbox though. I have even managed to bump up the power of Dolphin modules to over 1W and reduce most of the RFM23 to 3.3V so it runs cooler. I found adding a 5v to 3.3V level convertor solved my bluetooth issues.
The LORA one seems very simple to do and looks to have great range. Only caveat is the telemetry is one way (for monitoring only, right now).
DL is hard to get, yes. I have it and it is good though.
Yes, the pod is my own design and build. I tried 3D printing, but I found lasercut multiplex to be much lighter. It's 3mm, but I think you can easily go down to 1,5mm for the pod, halving the weight. I also designed that wing to hold the airspeed tube. It's really nice for serving and accessing the electronics.
The LORA solution looks amazing! I really want to try one. I have experimented with the ULRS, but I haven't found it to be reliable. I had a Wolfbox Rx and Tx flashed but the Mavlink came in with a 10s delay. Also I couldn't get the Bluetooth link from the wolfbox to the pc working. Since it's not open source I couldn't go in and debug it so I abandoned that route.
The dragonlink looks like a great solution too. It seems to be sold out everywhere, though. :(
You would only need your tailplane dipole for any of those. To make it bulletproof add a 900mhz RFD900x radio that can do failover PPM and Telemetry. But that is overkill maybe. I think DL V3 is the easiest thing but it will set you back $300.
Did you make that electronic pod yourself? Would love one for my Ranger.