Hello there, folks.

I think I've finished the sketch for my build. It's a 7", 6S, Walksnail, ELRS running Arducopter. But this is the first build I'm attempting to. I would like to ask for the guidance of more experienced users to maybe give me a Go/No-Go for the parts I'm choosing. I'm also working on a wiring diagram just to be sure I'll know where to connect everything. Here's the list:

FC & ESC Stack: Diatone Mamba H743 V2 MK4 & Mamba F55_128K BL32 4IN1 ESC 55A 6S
Frame: HGLRC Rekon7 carbon fiber 7" frame
ELRS Receiver: RadioMaster RP4TD ExpressLRS receiver 2.4GHz
GPS & Compass: HGLRC M100 5883 (M10 chip) with compass QMC5883
VTX: Walksnail Avatar HD Pro Kit V2 (Dual Antennas)
Motors: 4x EMAX PRO Series 2808 1500KV 3~6S
Battery 1: ZOP Power 22.2V 5500mAh 100C 6S 122.1Wh LiPo battery
Battery 2: iFlight Fullsend 22.2V 8000mAh 6S Li-ion 15C
Buzzer: Vifly Finder 2 buzzer - 100dB w/ Battery & LED
VTX Antennas: Antenna FlyfishRC Osprey 5.8Ghz 130mm SMA LHCP
Propellers: QProp 7045 propeller, 2-blade, CW CCW PC, 8 pieces
LED Strip: 20 RGB LED strip 3.5x100mm
Telemetry radio: Micoair 915MHz LR900-F pair

There's also a spreadsheet with all the parts and URLs for Banggood and AliExpress, just in case.

The reason I'm getting this FC in particular is for its suitability for the Arducopter firmware. I'm planning to 3d-print some other parts to the frame for fitting the VTX and telemetry radio.

My biggest concern right now is the relation of weight, props, motors, ESC, batteries. If it will be able to handle it for a "long range" flight. I'm not very much interested in acrobatics or racing for this build as I'm for exploring, so I'm not much concerned with speed. But I also don't want it to be super slow, haha.

Any tips here? What do you folks think? Thanks!

It is for a longer word count, most of the selected components are more or less fine. But as for the HQProp two-blade propellers on a 7-inch quad weighing over 1.6kg (with 8Ah Fullsend and GoPro attached), they will vibrate like hell. And two-blade propellers are not even any more efficient at this AUW, I have tested it. For effective range and minimal vibration, I recommend HQProp J75 or Dalprop T7057C. And I think the Rekon is on the smaller side, so 7.5 inch propellers won't fit. And I also have doubts that the 8Ah Fullsend will fit on the Rekon if you put the GoPro in front of the battery.

(15-Apr-2024, 01:57 PM)MomoBrut Wrote: It is for a longer word count, most of the selected components are more or less fine. But as for the HQProp two-blade propellers on a 7-inch quad weighing over 1.6kg (with 8Ah Fullsend and GoPro attached), they will vibrate like hell. And two-blade propellers are not even any more efficient at this AUW, I have tested it. For effective range and minimal vibration, I recommend HQProp J75 or Dalprop T7057C. And I think the Rekon is on the smaller side, so 7.5 inch propellers won't fit. And I also have doubts that the 8Ah Fullsend will fit on the Rekon if you put the GoPro in front of the battery.

Thanks, man. This is really comforting. Right, by the time you replied I've already bought the props, but not the 2-blade HQProp 7045 I had listed, as I was not able to find it in stock online. Instead, I have bought a set of generic 2-blade 7042 propellers, and another one of 2-blade 7050. But your messaged inspired me to buy the J75 you mentioned, so I went ahead and bought these as well, I'm going to experiment with these sets.

For the GoPro not fitting, I don't have one, and to be honest I don't think I'll buy one anytime soon, nor any other action camera, IDK.


Thank you, MomoBrut!

Edit: Also, the motors I listed were too out of stock. So I ended up choosing the Brother Hobby 2808 1350kV. That's what I'm going to use.

For efficiency of 6s 7inch LR is 1350kv better than 1500kv, with bigger kv the quad is unnecessarily more aggressive and less efficient...

(15-Apr-2024, 07:02 PM)MomoBrut Wrote: For efficiency of 6s 7inch LR is 1350kv better than 1500kv, with bigger kv the quad is unnecessarily more aggressive and less efficient...

That's what I've heard, too. So I decided to go with 1350kv.

Lose the Osprey and go with something else. Cherry 2 or Lollipop for budget, TrueRC ideally, but spend some money on it if you can afford. I've seen a few bad reviews for the Osprey on YT, I wouldn't risk it on what you are building. Get the absolute best antennas you can. Last thing you want is losing video due to using cheap antennas.

(16-Apr-2024, 08:06 PM)Pathfinder075 Wrote: Lose the Osprey and go with something else.  Cherry 2 or Lollipop for budget, TrueRC ideally, but spend some money on it if you can afford.  I've seen a few bad reviews for the Osprey on YT, I wouldn't risk it on what you are building.  Get the absolute best antennas you can.  Last thing you want is losing video due to using cheap antennas.

After messing around with analog antennas I swear by True RC antennas with Foxeer running a close second.

The FlyFishRC Osprey antennas are actually really good in my experience, and not expensive either. I have one on a Caddx Vista in my FlyFishRC Volador II VD5 frame and was impressed enough that I bought some more as spares or to use on other builds. They seem to be as good as the Rush Cherry antennas, and they are a bit smaller / lighter too which is a bonus.

I am not too picky with my antennas, I mainly buy cheap, but I don't fly LR. I have a few Osprey's (they are one of the cheapest) and they seem to perform quite well, but their antenna tube is very fragile and will break on medium crashes. You can of course tape them up or just cut down the tube. The Rush antennas can also be found cheap and are decent quality too. TrueRC certainly are nice and I heard each one is tuned, but I found it hard to justify spending 3-4x the price.

(16-Apr-2024, 08:47 PM)mstc Wrote: but their antenna tube is very fragile and will break on medium crashes.

This was one of the main complaints I've seen.  They aren't very strong and won't take the sort of abuse we tend to put them through.

For me if I had to choose between them and Cherry's, i would take a Cherry every time.  But if I was building an expensive LR rig that might be flying many miles away from me, it would be the best antennas you can buy, regardless of cost.  When failure might include losing a quad that cost a lot of money to build and time to configure, cutting corners and skimping on costly parts, should not be part of the process.

The Cherry antennas have a slightly more flexible tube than the FlyFishRC antennas which allows it to flex a bit more before it snaps, but the bottom line is that no-one is going to be flying a 7" LR quad in bandos or through tight gaps with a 130mm long antenna sticking out the back, so the durability of the antenna stem is really a moot point. If someone is unable to fly a LR quad in upright cruising mode or along mountain tops without crashing it then they probably shouldn't be flying it.

Thanks, everyone. This was an opportune discussion. I already bought the Osprey's antennas, and I should confess that only after buying I went looking for reviews online, and results are questionable. I wonder if I would be better using the antennas that come with the VTX. I have invested quite a good amount of money already, so I'm planning to cut costs, but I understand that the antenna might not be the best place to do it. So I'm going to perform some more searches on the internet, and I might end up using another antenna, IDK.

Anyway, thanks a lot, folks!

Unless you are planning on flying the quad in bandos or through small gaps then I would personally just stick with the FlyFishRC rather than getting a Rush Cherry. They both have the same sort of signal quality. It's just the tube which is a different material between the two of them. If you want the best of the best then just pay a premium and get a TrueRC antenna. Both TrueRC and VAS antennas are considered to be the cream of the crop in the FPV world.

(17-Apr-2024, 03:51 PM)UglyBob Wrote: Thanks, everyone. This was an opportune discussion. I already bought the Osprey's antennas, and I should confess that only after buying I went looking for reviews online, and results are questionable. I wonder if I would be better using the antennas that come with the VTX. I have invested quite a good amount of money already, so I'm planning to cut costs, but I understand that the antenna might not be the best place to do it. So I'm going to perform some more searches on the internet, and I might end up using another antenna, IDK.

Anyway, thanks a lot, folks!

I second Snow.  You already bought it, so you might as well use it.  I wouldn't get a Cherry or Lollipop to replace it.

If you find you are hitting the limits of it, then go up to TrueRC or VAS.  But I suspect going to helicals or decent patch antennas on your goggles might give you a couple more miles, if that's where your path is leading and then if you are pushing it even further then go to the expensive antenna.

Unpopular opinion -> flying my 7" between 1-2miles, I find that the rush cherry match even my VAS long range antennas for clarity and signal. I have cherry long antennas on one and the VAS on the other and haven't felt a significant difference.

Now since I fly dji, I do have the vas cyclops antenna on my goggles when I fly longrange and it has made a marked difference in reception at length