Since the video is not that good on my other quads, I didn't have a memory card for my goggles. I am getting Micro SD card and will get videos the next time I fly and post one.

I received the Micro SD cards, got some video, tried to upload...then found out that I had to use an external site to host my videos and just put the link on this site. Whew. Ok, I finally got all of the pieces together. The following video is my GepRC Phantom at a local soccer field. Just an easy flight; no fancy tricks.

Got my Phantom two days ago and I love it! The build quality is great and it's so much easier to work on than my Eachine Trashcan.

When I got it I first checked if all screws were tight and discovered that one screw for the camera was missing, so I had to shorten an M2 screw I had lying around to fix that. I replaced the VTX whip antenna with a polarized AXII antenna, added a beeper and a FS-RX2A receiver. I'll replace that receiver soon with an Oversky XR602T-A though because it has two antennas and RSSI output.

I have not upgraded the Betaflight firmware or the ESC's because I want to feel how it flies out of the box. With my Trashcan I made the mistake (https://intofpv.com/t-hello-everyone--10535) to upgrade too soon and I'm not sure if it flies better or worse now.

The weather has been pretty bad here lately but I did give the Phantom it's maiden flight in windy weather. It managed quite well but I didn't feel too confident about doing tricks because the wind made it drift too much. The PID's do seem great, I didn't notice any weird wobbles or oscillations, not even propwash. The standard props seem a bit weak though; I noticed a lot of drift while taking corners, and to get out of a dive I had to give it full throttle. I didn't make it out of one dive, so the kwad got a taste of the dirt at the football field and the battery experienced flight on its own   This brings me to the fact that the supplied battery straps aren't that great, I'll be replacing those with some RJX Hobby straps which I hope provide some stickiness.

When the weather allows I'll fly again soon with the HQ Prop T65 and Emax Avan Rush props I got. I'm very curious if the kwad gets more grip with those, and if they affect flight time a lot. The standard props gave me a little more than 6 minutes of flight time with a 450 mAh battery, which I'm very happy with!

Pictures right out of the box:






After the first flight:

(01-Mar-2020, 11:48 PM)L0stB1t Wrote: Got my Phantom two days ago and I love it! The build quality is great and it's so much easier to work on than my Eachine Trashcan.

Nice  Is there any particular reason you moved the antenna wires from the tubes to the arms? I prefer the tube set up if and when it's possible to do that, but that's just my own preference.

I'm still waiting for the weather to sort itself out here so I can take mine out again. It's been hanging on the wall since October last year looking all sad for itself. I managed to brave the weather and take my 5" out 3 weeks ago but since then it's been non-stop storms here, and my usual flying spots are totally water logged.

Anyway, you should know the rules on here by now...DVR footage or it didn't happen  

I like the look of the tubes in the back (makes it look like some insect tails) but I read somewhere that they rotate too easily in a crash and then get in the way of the props, causing more damage.

Upon getting the kwad I agree that they rotate too easily, plus I think there's already a bunch of stuff in the back (capacitor, beeper, VTX antenna, battery wires and connectors) so putting the receiver in front and the antenna's on the arms seemed the best choice to me.

I only have crappy DVR footage from a ROTG02 connected to my smartphone since my SKY01 goggles don't have a recorder. But I'll try to cut out some of the best parts in order to follow the rules

(02-Mar-2020, 01:34 AM)L0stB1t Wrote: I like the look of the tubes in the back (makes it look like some insect tails) but I read somewhere that they rotate too easily in a crash and then get in the way of the props, causing more damage.

Upon getting the kwad I agree that they rotate too easily, plus I think there's already a bunch of stuff in the back (capacitor, beeper, VTX antenna, battery wires and connectors) so putting the receiver in front and the antenna's on the arms seemed the best choice to me.

Yeah, that's a fair comment. The tube mount is only attached to a single standoff so I can see it spinning round on the standoff being a problem. I haven't flown/crashed mine enough yet to notice that issue. If it is, then I will likely try to come up with a solution to address that while still keeping the tubes. The first thing that springs to mind is a modified 3D printed bracket with some tabs or similar that go either side (and/or inside) the "V" on the bottom plate to hold it still. Alternatively the poor man's option of some glue with the current TPU mount to stop it moving on the standoff  

There's no beeper fitted to the Phantom from the factory (at least not on the ones sold last year), but I fitted a self-powered buzzer one behind the camera which takes up all the space there, so I have no option but to keep my receiver at the back.

I think it might be possible to prevent the tails from rotating by cutting a big V in the bottom of the tpu part, it can have notches left and right of the carbon fiber. A bit of glue is not too bad either, I don't see much reason to detach the standoff from the bottom plate a lot.

I only added a simple unpowered beeper but seeing that the kwad's battery can eject pretty easily I'm definitely considering the FullSpeed Lucky Box like you're using  

Finally, here's how a beginner struggles to keep his kwad in the air during windy weather:

Since my last post, I have made one update, the VTX antenna has been changed to an iFlight omni and a matching one on my Viper goggles. 

So far, I have never had a battery ejection, not even close. I did, however, add posts to the front two stand offs, have secured the battery leads up the back, have a battery pad the length of the batteries and I use two Velcro straps. The batteries literally have no place to go. They just stick like glue.

I still have the XM+ that it came with (mounting and all). My antennas are pretty solid and have not moved during any of the crashes (yeah, I crash a lot). This might be because I mounted a VIFLY self powered buzzer directly below the antennas and secured it with a zip tie. I stuck a piece of battery pad on the buzzer so it would "sink" into the antenna mount. Everything on the back end is pretty solid and I can easily reach the buzzer.

As for RSSI, the XM+ outputs RSSI on channel 16 which is AUX12, but it does not come configured in Betaflight from the factory. Once I set the RSSI to AUX12, I now get RSSI. From what I can tell, it reads around 75 from about 1000-1200 feet out. As a comparison, my EMAX Tinyhawk Freestyle RSSI is less than half of the values at any comparable distance.

Also, I set up a MODE switch so I can change between Angle, Horizon, and Acro modes. 

Overall, I am really happy with this setup; it flies good and is quite durable. So far, the quad has not sustained any damage from all of my crashes; even the HQProp T65mm T-mount bi-blade props are showing very little signs of wear.

I stripped the beeper pad on my flight controller   This happened because I had the beeper soldered directly to the FC, without any wires. A little bump against it was all it took to break the pad off...

Luckily it's possible to remap ports but since a beeper uses more current than normal ports can provide, you need to add a transistor. Well it's even better to get a beeper with a battery so I got the FullSpeed Lucky Box which is really perfect for this kwad. So I soldered it to the 5V, GND and unused LED_STRIP pad and with the following BetaFlight magic it works great:

resource BEEPER 1 A08
resource LED_STRIP 1 NONE
feature -LED_STRIP
set beeper_inversion = OFF

I moved the capacitor a bit (and replaced it with a top quality Panasonic) and secured the Lucky Box with two tiny cable ties and a drop of glue:

Looks good. Where did you get the red standoffs? Are they 2mm?
I have just switched props to the Avan Rush 2.5 tri-blades (like in your picture), but have not been able to fly due to the coronavirus. Can't wait to see how it flies and compares to the HQProp T65mm 2.5 bi-blades which were giving me about 7 to 7 1/2 minutes fly time with 600 mAh batteries.

I have been flying this with a 2S battery setup (2 1S in series), but I have a 3S pack that I will try the next time I can fly.

A plate has been attached with the back 2 stack bolts to hold the U.FL antenna connector in place. This works.

The standoffs are M2, 20mm long, just like the originals. I got them from AliExpress: https://www.aliexpress.com/item/33004382274.html

I really like the Avan Rush props, they give a bit more grip than the bi-blades. They are really tough too, I've done about 10 flights, with quite a few crashes, and the only damage is a little dent in one of them. Maybe they're even a bit too strong, because after one crash I had a bent motor shaft and a slightly bent frame, so I've replaced those and still run the same set of props!

I hope you get to fly soon, you'll love the 3S. Is the quarantine that strict where you live? Here in Belgium we're allowed to go out to do sport or walk your dog as long as you're alone or with people who live under the same roof, and keep your distance to anyone else. So I don't think the police would mind me standing by my own in the middle of a field.

Here's my session today:

Hi L0stB1t,

Thanks for the link.

Where I am at, we have a "Stay-at-home" order...only go out for essentials, food, drugs, necessary items. If we go anywhere that I can fly, it is either closed and/or we get hassled about not being at home since flying my drones is considered non-essential. In fact, the field where I fly has been closed for some time now.  I guess that just is-what-it-is. So, I will just have to wait. I am glad to hear that you like the Avan Rush props. These were the originals on my EMAX Tinyhawk Freestyle, but I switched to the HQProp T65mm props to take out some of the aggressiveness. At that time, they were just too fast for me. Now, I am a little more "seasoned" and can handle things a bit better. So... I have put them on the GepRC Phantom...getting things ready to go. 


PS:  Like the flight video 

Today I upgraded Betaflight to 4.1.5. It's a bit of work to get the config back the way it should be, comparing the old diff to the new diff line by line. Most differences are logical, but for some reason it also needed a "set gyro_1_align_yaw = 1800" line in combination with the "set align_board_yaw = 90". You also need to set up the VTX tables but that's totally worth it.

I flashed the ESC's with JazzMaverick G_H_30_48_REV16_8.HEX and set up RPM filtering. Used the recommended Gyro RPM filter and Dynamic Notch Filter values from Joshua's "Betaflight 4.1 RPM filter best settings to kill propwash" video, and put the filter sliders at a safe 1.3 value to start with.

And it flies... like crap:



As you can see here was a lot of wobble when pushing the kwad around. The first part was with standard 4.1 PID's, profile 2 and 3 with the PD balance and PD Gain sliders at 1.2 respectively. I used the Speedy Bee app on my phone to try more changes (not in this video) but couldn't really find anything perfect. Putting the filter sliders all the way to 2.0 did help a bit, just like Joshua mentions in his video. I realized too late that I should have saved one profile with the original Betaflight 3.5.7 PID's (without the sliders), so I haven't tried those yet. The motors were never too warm, but I do think the flight time was pretty short, although that could just be caused by the repeated rocketing over the field. And maybe it's just me, but aside of the horrible wobble the movement did feel more locked in.

Sadly, I also crashed pretty badly while trying a powerloop, and now my frame is bent and cracked, two props completely bent (the Avan's are tough but not indestructible!) and the UFL connector stripped off the VTX. Luckily I still have my previous frame (which only has a little bend in one of the arms) and the VTX is not totally lost, the UFL connector can be replaced. I've ordered some new ones but for the time being I directly soldered a simple short monopole antenna on. When I get the UFL connectors I'll definitely add a piece of plastic between the back 2 stack bolts like iFly4rotors did, this should prevent what happened to me.

Anyway, concerning Betaflight 4.1 I would definitely not recommend anyone to try it unless you love to experiment more than you love to fly. Once I fix my kwad I'll try to tune it better, I'm still hopeful because there's at least one person who seems to have a great tune:

Hi L0stB1t,

Snow posted the original 3.5.7 CLI "Dump" on page 1 of this thread...if you need it. Being a retired software developer (programmer), I save and backup everything...more than once...just to be safe. You never know when you will need to go "back" one or two revisions. I am a little "old school"...if it ain't broke, don't fix it . Only time I upgrade anything is when there is a really compelling feature that I can not get any other way, but that's just me.

As for the broken Vtx connector. I have the UFL (extremely tiny) solder on replacements. However, these are so small that I may not use them. On one of my quads, I did solder on a simple bi-pole, but now I have a better idea. I have MMCX extender cables just for this purpose...cut the cable and solder the female end to the Vtx. This method allows you to keep some length on the cable so it can be secured and I like the MMCX connector better.

Nice flight videos. The last video is really good, nice space, good flight path. If I had that space, I would fly every day. 

Have fun and stay safe.

After the crash the frame's bottom plate was even worse than I thought, but I totally fixed the bent arm of my previous bottom plate. I applied heat and pressure simply by wrapping it in a single layer of parchment paper, putting it on a hot electric stove (glass plate) and pressing it down with a hot iron on top. After heating it on both sides for about 10 seconds, the arm is perfectly flat again! It looks just like a new piece and feels just as strong. It survived my flights today with some rough landings so I'm really happy this worked!

The simple monopole VTX antenna also worked just fine. Why even bother with polarized antennas    Granted, due to Corona I'm only flying at the nearby football field nowadays, where I won't fly behind trees or other objects that could disturb or reflect the signal.

Thanks for the suggestion to use MMCX connectors iFly4rotors, but I was wondering if these don't weigh too much? I know they are not as heavy as SMA connectors but still?... Just like you I'm also into IT so I also take lots of config backups. I'm even considering putting them in a Git repository so it's easy to keep track of all changes. It's also great that SnowLeopardFPV saved the original configs in the first post, very smart and helpful for those who forget to do this.

To tune the PIDs I wanted to start from the original ones, and follow the UAV Tech guide as good as possible:
https://www.youtube.com/playlist?list=PL...fEZB-BKkiQ
https://tiny.cc/uavtech
https://drive.google.com/file/d/1WxgSUsG...1Ddmq/view

I put the filter sliders back at 1.3, disabled D min completely (in order to find the best D value), put I-term relax at 10 (to just concentrate on the P and D terms) and put all Feedforward values to 0 (again, to concentrate on just the P and D terms).

The basic process as I understand it is to increase P until you get overshooting (fast wobbles) when doing flips and then back it down again. After that, increase P and D together while maintaining the same P/D balance, which should help with propwash.

Now, trying to put that theory in practice is not easy because I'm not entirely sure what to look for (or listen or feel). So today I basically ended up with increasing the numbers a lot;



I think it flies quite well now and the motors don't get hot, but I kinda doubt these numbers are actually good since they are crazy high compared to the original 3.5.7 numbers. I'll slowly make more changes (and enable D min again, increase I term, add Feedforward, reduce filtering) but there are so many variables it's really hard to tell what effect is caused by which value

Anyway, here's the final flight of today. As you can see I added extra information to the OSD, which was really helpful during and after the tuning. Somehow I also nailed the pretty cool 180°-backflip-and-slide move (does it have a name?) which I'm pretty proud of: