This is like something I thought I could get away with flying around the local area.   A whisper quiet, light, cruising rig with high fidelity fpv.

After a few build iterations I ended up with this:


Based on the Dragonfly V2 frame with a dry weight of 78g, this quad has the following build specs.

• betafpv 12A aio, 2022 version with spi elrs RX
  
• tmotor 1104 7500kV motors
  
• naked avatar mini vtx V3
  
• avatar hd pro camera
  
• nbd mini gps module
  
• truerc lhcp antenna
  

Designed to run on 2S, I'm getting approx 4 minutes of cruising per 500mAh of capacity.  I'm going to test some larger packs soon, around the 1100mAh mark to see how the flight time goes.

The frame has a few improvements over the first version.  This version also comes with struts for the arms which is great.   The AIO mount plate is strengthened noticeably. 


The AIO is configured with BF4.5 nightly and Bluejay 19.2 @ 48K.  Elrs is spi so its baked into betaflight as version 3.x something, so that's fine for me.   I removed the enamel wire antenna and soldered on a mini-T antenna instead.

The motors always seem to come from another project so some wire lengthening was involved and I still couldn't get it right.


I wanted to try out the high end pro camera.  I removed the back casing and a couple of screws to lighten it up a bit.  I used the nano cam(vtx lite kit) mipi cable as it is the shortest.   The canopy is a bit flimsy but the only 19mm one I had on hand.  The hd pro camera is HUGE!


The vtx is the V3 one that can run up to 500mW, I'm counting on that extra power and the 2S compatibility is great!

Here the parts are coming together and I also installed the nbd gps unit on the arm strut.   


Initially I was quite pleased with the way the antenna mount came out, but it gave me crazy null zones with I turned the quad around to come back home.


I ended up mounting the elrs antenna in a vertical fashion which has helped signal reception considerably.  I also swapped out the foxeer lollipop that was top heavy and went for a stripped down truerc antenna that had its heatshrink removed.  It bobbles less than the top heavy foxeer which killed handling.


Will post video once I work out the tune a bit more and battery capacity testing. 

The quad has 3" biblades on it at the moment but can fit 3.1" and 3.5" props as well.  I might need to upgrade from 1104 motors though.

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Nice, how are you liking the pro camera? I would say go for 3.5" props if your frame can fit them, but 1104 does seem a little too small even for the biblades - still worth a test flight.

Well the camera is big!  That took a bit to get used to.  So far the image seems really nice but I'm yet to fly at dusk or in the evening.  I was hoping for more configurable camera options but there doesn't seem to be any.  I noted what you mentioned in Quad68's iflight quad thread about the warmth of colour (or lack thereof) etc.  I'm hoping to get more time with it this evening and on the weekend.

Yeah 1104 is pushing it.  Ususally they could handle 3" biblades but the weight is a bit on the heavy side.  I'm thinking maybe some 1303's or similar so I can go up to 3.5".  Just trying to find a balance on current draw so I can go the distance.

For now my main concern is video range, I'm hoping the obnoxiously tall antenna helps!

Curious to know what your dry weight came to. Seems like you had a pretty similar idea to what I did.

I don't get it with the awkward size of the pro camera either, it weights even more than the O3 and feel its more awkward to mount. The Polar and Polar nano cameras are both "normal" sized so its a mystery why they had to double the size. I have mine in a frame for O3, but I think the weight is causing the camera to wobble in the silicone mount so haven't really flown it much.

I was thinking 3.5" biblades for the 1104s, but they might be a little much. 1303.5 do ok for a 3.5" cruiser. I tried that on a toothpick with 2S, but maybe my kv was too low (4500?) - control was too sloppy and I didn't get impressive flight times either, but it was decent on 3S. But it will be interesting to see how your 1104s do with a larger battery. The GNB 850/880 HV would be a good one to try if you have one.

Yeah, I'm doing 1203 7000kv on 3" 2S and it's perfect. I'd bet 7000-10000 is a better range for 2" 2S.

Quote:Curious to know what your dry weight came to. Seems like you had a pretty similar idea to what I did.

78g dry.  Yeah I saw your thread, was inspired.   

 

Quote:I don't get it with the awkward size of the pro camera either, it weights even more than the O3 and feel its more awkward to mount. The Polar and Polar nano cameras are both "normal" sized so its a mystery why they had to double the size. I have mine in a frame for O3, but I think the weight is causing the camera to wobble in the silicone mount so haven't really flown it much.

I was thinking 3.5" biblades for the 1104s, but they might be a little much. 1303.5 do ok for a 3.5" cruiser. I tried that on a toothpick with 2S, but maybe my kv was too low (4500?) - control was too sloppy and I didn't get impressive flight times either, but it was decent on 3S. But it will be interesting to see how your 1104s do with a larger battery. The GNB 850/880 HV would be a good one to try if you have one.

Yeah it kinda reminds me of the caddx kangaroo camera.  Really long lense mount which always had issues with canopys.
I have the gnb 850mah HV in stick form.  I feel they are more a high 680mAh from my use in 1S toothpicks.  I've ripped apart a tattu gen2 850mAh 4S pack and they (as single cells) performed better and could handle a higher current draw.  I also know I push things a bit, just for context.
Yeah I'm pushing the 1104 with the 78g weight.   It flys better in light to no wind of course but still a bit of wobble.  I do want to carry a heavier battery so I might reverse the process and start there.  I'm ripping apart a tattu gen3 4s 1050mAh pack to make 2S packs for this rig.  They will be heavier so maybe I need to factor that in first then see motor/prop combo.
As Suros notes the higher kV range for 2S on 3 inch, it's harder to find high kVs as motor size increases.  Maybe i need to stay in the 110x footprint and try a 1106 maybe that has a high(ish) kV available?

Calmer day today. Still using 2S 500mAh packs, getting approx 4 minutes flight time. I pushed it down two blocks from me, LQ stayed above 98, even when cornering and video was still three bars and clean.

Ok, so testing the custom pack made from a tattu 4S pack. It is 1050mAh 2S. I'm getting 10 minutes of flight. It's funny, the landing voltage with motors running is no different to the disconnected (no load) voltage after the lipo is removed from the quad. Definitely no batt sag here

So tonight the conditions were right for another test flight.  Just slowly pushing it further.  There was a slight headwind going out so I felt more confident on coming back if I misjudged battery life.   Test flights gave me 10 minutes on the 1050mAh 2S pack.  In reality I'll prolly get less.  This flight was 4 minutes long and battery came in at 3.75V/cell, so I've got a bit more in the tank but not 10 minutes.   This 2S pack would be good for a 1.5km out and back flight in mild conditions I reakon.

This evening I got out to 560m.  Running 500mW on the vtx at 720p25mbps standard bitrate.  True RC omni's on my goggles with a high mounted tx antenna.  Video never drops below 4 bars or 25mbps so I know I can get further out. 


The HD pro cam is great for this time of day.

Hi ph2t,

Nice Build.      Good Job.  

Later, My Friend, iFly  

Looking excellent!

You should definitely give 50Mbps mode a chance. I used to avoid it because everyone said that the signal held together better at low bitrate, but then I actually tried it for myself. All of the places I fly have actually retained just as much signal performance, and my image has been considerably clearer due to the extra bandwidth.

Quote:You should definitely give 50Mbps mode a chance. I used to avoid it because everyone said that the signal held together better at low bitrate, but then I actually tried it for myself. All of the places I fly have actually retained just as much signal performance, and my image has been considerably clearer due to the extra bandwidth.

That's interesting as I've configured it to what I thought would benefit for range, 25mbps, 720p at standard bitrate.   Usually, I've found this to perform the best whilst flying around the house, given penetration and all.  I will try 50mbps for sure.

Another mild weather day, thank you.  I got out to 900m this time.  Video dropped off very quickly and the red boxing around the video feed gave me bugger all warning.  As I turn around at the 900m mark you see the bitrate almost at zero!

I'm yet to configure RTH so I really need to get onto that!


The lack of an accurate altitude is really starting to annoy me.  I picked up the V3 of the betafpv AIO and it includes a baro and blackbox.  Hopefully I can get a more accurate altitude reading with this.


I've got some more ELRS T antennas coming, ones with 95mm long wire.   I'm hoping to get greater clearance from the canopy and also have a cleaner mount of the RX antenna as it is distorted a bit at the moment because of the way the heatshrink has squished it to the zip tie.

Trying for 1km soon 

I've seen that sort of signal drop before. You got far enough out that a rooftop obstructed line of sight. My local obstruction is a brand new storage unit facility. The second I get below that, a perfect signal turns to barely hanging on.

Looks like it endures the wind quite well though. Just little bumps up there. How's the ground wind speed?

Is that the v2 or v3 VTX and you have it at full power? I would have thought the 350/500mw would get you past 1km assuming you have clear LOS. Which patch antennas are you using and were they pointing in the right direction, at that range if your head facing is off slightly that could affect your reception. You can try some slow head turning if you see your signal dropping. Or maybe its the rooftop issue Suros mentioned.