Hello Fellow Flyers!

[Paul!]

Hi all,

I'm new to flying, and eager to learn! I built the FT explorer kit as my first plane. Probably not the easiest first model airplane experience . I managed to get it under control, and luckily I have another kit waiting to be built!

Aside from fixed wings, I want to have a go at FPV quads. My first build is a Gremlin. I bought the build kit from the FT store, with all the accessories. I built it right away, but I'm having a problem. I hope someone here can help me. Can I post the issue here, or should it go into the Mentors space?

Big thanks to FliteTest for creating an awesome community and great videos!

Cheers,
Paul

 

[French]

Feel free to post here, and welcome to FT!

 

[Paul!]

Thanks!

Problem Summary
I'm getting what seems like an intermittent signal from the receiver, when viewing the data in BetaFlight > receiver.

Setup
with a fully built gremlin
1. With transmitter (DX6e) turned off, plug the battery into the Gremlin, and wait for the orange LED on the receiver to blink fast.
2. Then hold the bind button on the transmitter, and turn it on. The transmitter says the bind is successful DSMX 22ms, if i recall correctly.
3. Plug into usb, and hit connect in BetaFlight.
4. Can confirm that the gyro and accelerators are working correctly by the 3D representation moving around correctly.
5. Go into ports, and enable serial on UART3.
6. In configurations, choose serial based receiver and Spektrum 2048 (I also tried 1024).
7. I can check that the motors are working by going to Motors, checking the warning box to say I wont chop off my fingers, and using the slider for each motor. They're not going in the right direction, but they're working.
8. Go into Receiver and choose the following settings:
Channel Map: jr / Spektrum / Graupner = TAER1234
Min: 1000, centre: 1500, max: 2000
RC interpolation: auto

With these settings I get what looks like intermittent signal. The bars flicker from 0 to 1500 (half way) at irregular intervals.

Other notes
I have not updated the firmware on the flight controller.
MultiWii api version: 1.21.0
FC identifier: BTFL, version: 3.0.1
Firmware released on Oct 18, 2016
Board: SPEV, version 0
I re-soldered the signal wire from the receiver to the flight controller. No effect, but looks worse .
I tried it with a second and identical receiver, and had the same issue.





Any help is greatly appreciated!

Thanks,
Paul

 

[PsyBorg]

I see several wires with stray strands sticking out. Clip those off so they do not short on anything before you power that back up. Maybe put a little more solder on the positive battery lead as that looks awful sparse and that's gotta carry current well.

The screen shot of beta flight shows it is running firmware from oct 18 2016.. Thats near a year old. I would look into that and reflash to a newer version. I know there is newer firmware for the SPF3 Evo then that.

Start with those two things and get back to us for any changes either way if you would.

 

[Paul!]

Thanks for your help, PsyBorg! I took the whole kit to work, and played with it during lunch . The firmware flash did help! The receiver seems to be functioning! Silly me thought that since the board came up ok in BetaFlight on first boot, and all the sensors seemed to be working, that I didn't have to flash like they did in the build video. I guess flashing firmware is always a good idea with a new flight controller. Lessons learned .

I haven't been able to get the motors to move other than using the sliders in BetaFlight, however, but I've only had a few minutes to play with it. I'll try again after work and let you know how I fare.

Thanks!

 

[flitetest]

Hey Paul!
Welcome to the wonderful world of FT FORUMS! We are happy to have you along for the ride!
Keep asking questions and gettin involved, you never know who you might help along the way! ha!

Blessings and good luck with the Gremlin build, You are in good hands... they are a BLAST to fly!

Stefan

 

[Paul!]

Hi Stefan, Thanks for the warm welcome!

Ok, so I have the latest firmware, but still encountering an issue.

Problem Summary
With the transmitter bound to the receiver, and the Gremlin's battery connected, and no USB connection, and with it armed, I cannot get the motors to spin using the transmitter.

Setup
Previous setup + new firmware on the flight controller.
1. Confirming the receiver is working, and the 3D model in the "reciever" tab reacts according to my transmitter input.
2. Go into modes, and setting AUX1 to arm, and AUX2 to the 2 flight modes. Signals are receiving correctly.
3. Go into Motors, and spin all the motors to determine direction, and minimum stable speed.
4. Go into configuration and set minimum throttle (set mine to 1040).
5. Disconnect from BetaFlight.
6. Connect to BLHeli and read setup. I inversed the ones spinning the wrong direction, and wrote the setup to the flight controller.
7. Disconnect from BLHeli, and unplug USB and battery from the quad. Then plug in only the battery.
8. I switch the arm switch on the transmitter (with it turned on), but no movement. Throttling up doesn't make the motors spin either.

Other Notes
- The batteries deplete even when USB is plugged in. Watch that you don't discharge the battery too much! I believe the flight controller started beeping at me to tell me the battery was low.
- I have not flashed the firmware on the ESCs. I will try that as soon as the battery is charged again. As the motors are spinning up fine using BetaFlight, I'm thinking they should be working. Hopefully someone will be able to give me an idea while I wait for the batteries to charge back up.

Really appreciate all the help so far!

 

[PsyBorg]

Watch this video and see if one of these issues are not tripping you up mate.

 

[Paul!]

Thanks PsyBorg. I saw you post it in another thread earlier today, and it was fantastically helpful!

Problem/Solution Summary
Problem 1: when I first plugged in the gremlin flight controller and launched BetaFlight, everything seemed to be working fine. I could flip the board around, and the 3D model would follow. I could save all the settings, and after soldering, I could move all the motors via BetaFlight. HOWEVER, the software was not working right. With the receiver hooked up, the signal coming in was sporadic.
Solution 1: Update firmware! Lesson learned: always install the latest compatible and stable firmware.

Problem 2: With my DX6e setup to arm on AUX1, and all the signals seemingly coming in well, I assumed that arming was working. It was not. My minimum throttle was stupid high (around 1150), and for safety it won't arm above 1000 (yours may be different).
Solution 2: First I reset my safety limit to 1010 in BetaFlight using the console. Then, on my DX6e, I went into Control Setup (click on big scroll wheel), then scrolled over to Travel and increase the max and min from 100 to 146. That got me to 1002 and 1997, the closet I could get to the edges within the 1000 - 2000 range. Lesson learned: there are many lessons to be learned . I didn't know about the safety features described in the video above. They totally make sense!

It's been a fun ride already! now it's time to fly .

See ya on the flip side! (can a gremlin do flips?)

Cheers,
Paul

 

[Paul!]

I'm a little embarrassed to say I spoke too soon. I think I may have an issue with the auto leveling?

Problem
The motors spin up smooth under betaflight, but are jittery when not connected to betaflight.

Setup
- I flashed the latest firmware on the ESCs
- I calibrated the ESCs in betaflight by bringing the fader up, connecting the battery, and bringing it back down. The noises tell me all went well.
- I calibrated the flight controller sensors on a flat surface.
- When I unplug everything, and only plug in only the battery, I can arm it and the motors will be jittery. When I increase throttle, I can get off the ground, but it spins rapidly, and veers off to the side.

Video of good motors: https://drive.google.com/file/d/0B5uIpnH3Yw1oR3A5NF95c0N0S2s/view?usp=sharing
Video of bad motors: https://drive.google.com/file/d/0B5uIpnH3Yw1oemlaam4yUDVNNUk/view?usp=sharing

 

[PsyBorg]

How did you mount your FC? Is there anything on the quad that is able to bounce around and strike the frame like battery strap or an antenna or the man battery plug?

Mount your battery properly as if you were ready to fly, unplug the usb cable as well. Turn on your radio then power the quad. once it boots arm it and see how it reacts. Then pick it up off the table and compare the changes. Bring the throttle up just a hair and then tilt each corner down one at a time. The lower motor should speed up.

I believe this is a vibration issue but could be a miss matched motor order or fc direction thing as well. Start by using two layers of double sided tape to hold the FC down.

and yes the Gremlins can do flips.

 

[Paul!]

So I added another layer of double sided tape, and made sure there was nothing vibrating. I think it's pretty secure.

Interestingly, at the start the motors were very twitchy. After running up the speed a few times, it started to steady out. Now it idles at a descent smoothness, only hiccups every 2-3 seconds. When I speed it up to a low speed, the hiccups are very frequent. Then when I spin it all the way, it is smooth again. After running it at a specific speed for a while, it tends to smooth out.

Motors do speed up accordingly when I tilt. I think... It's hard to tell which motors are speeding up. I'll pay closer attention next time.

I'm just recharging the battery. I'll try to grab a video when it's done.

Also, awesome video! I can't wait to be flying around like that

 

[Paul!]

Here's a video of the latest results: https://drive.google.com/file/d/0B5uIpnH3Yw1oZzhWdWhaMnlOSVk/view?usp=sharing

As you can see, it's still quite jerky. I've played around with the settings and trying to steady the FC, but haven't been able to get it to stop stuttering. Any ideas for next steps?