Mobula 7 HD Toothpick Conversion - "New" build

I decided to buy a new VTX and it arrived today, to keep things as similar as possible, I went with the HM ovx306, same format and ports but with added power. This is now working properly, so previous vtx was indeed at fault.
Also worth noting that I swapped the turtle out for the crux canopy and camera to be able to fly more aggressively on this thing.
Just as I was stepping out the door to have a fly test, it started to rain… LOL
Since I was really keen on testing this thing, I just went down to the underground carpark and flew a pack there to test it a bit.
I can’t fly aggressively in this location due to all the cars present, so it was a cruisy flight up and down one of the corridors, so nothing fast nor acrobatic, but I really like how it flew. I guess the combination of more power with the tri-blade makes quite a difference, It handles much tighter then the crux, I think I’m gonna be flying this mainly for a while now.
I’ll do some finishing touches like tape on the motor wires, loctite on the motor screws and maybe swap the the frame screws for slightly shorter ones.
Also noticed the motor screws are quite close to the motors wires and thought a spacer there should solve it, about 1mm will do, but I’m not sure what though. What do you guys usually use for spacers on that area? I though of maybe folding a duck tape cut out the holes to measure and just chuck it between motor and frame. Would this be ok?

Here are a couple of pictures with the current outfit just back from its first pack:

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That should work. Instead of folding just stick two layers onto the arms? Maybe even wrap the arm?

I usually just find shorter screws… but then I have loads!

Cool, will try that then, or just occurred to me, some shrink wrap…

Regarding the screws, I agree with you, but this motor takes the 1.4 screws and not the m2s (the props that m2 though, go figure) and since those are a bit more scarce I don’t have shorter ones nor did I want to shorten the ones I have…

In the end I had some m2 washers which held the screw head so I used those for now, they did the job just fine, still a bit of screw poking out but out of danger zone…

The weather was a bit nicer today, aka no rain (still a bit of wind, not strong but on the threshold for this drone), so I was able to go outside to give the little guy some full throttle. Everything worked as supposed, even the antenna which I soldered back together worked as before it broke, so I’m quite happy with the results. If I had to be picky, I don’t like the position of the RX, but with this setup is probably the most suitable. If I raise the FC a bit I might be able to position it better under it, but that will probably affect signal, as it is now. The other option would be to use a different canopy , which I’m avoiding. I’ll see how it goes, if it proves to perform bad I’ll consider my options and move it around.
With the 450Mah, I got about 6 - 6:30 minutes and with the 650Mah I got just over 7. From what I saw during flight, I don’t think it went over 15a at any given point, so all good on that side to. Curious to try this on a 3s now…
Also flew the overweight crux, poor guy, and same impressions from when I flew it on the carpark. As it is now, its just for cruising,

It’s flying really well but why not try to see if it can get better eh… So next part will be flashing bluejay, and playing around with the possibilities this enables.
Any tips for a easy and simple/basic configurations which I could do without having to re-engineer the whole thing?

Emuflight might be worth a play with. Its good with whoops

That one and Quicksilver are potential candidates, but I feel like sticking with BF for now. So far it has treated me good and I feel like on 4.4 it kicked things up a notch.

Went through with the Bluejay firmware and everything went smoothly with the process. Also enabled the RPM filter on BF, adjusted the motor poles to 12 and set the dynamic idle to 34.
Everything seems fine at the moment with the quick hover test but I’ll probably only be able to test outside tomorrow, it seems like it will be wet all day today. Looking forward to fly it and see how it feels…

Edit: just went back to have some checks and noticed the cpu load is now hovering on the 60% mark, whereas before it was around 30%. Would this be a problem or is 60% acceptable?

60 is fine. More filtering I guess :slight_smile:

Cool, I figured it was bc of the added filter but wasn’t sure if the load was ok to run with.

Guess the final proof will be tomorrow when I take it out for some tests.

Also if you upgraded from a 4.2 or below to 4.3/4.4 then they changed the CPU usage to be a bit more truthful (which meant a rise!) They basically changed the way it was calculated

It was 30% on the 4.4 version already, so definitely the rpm filter is to blame.

So the weather decided to collaborate this afternoon and I managed to get a couple of packs to test some of the changes…
Its flying even better now, I was watching a video earlier from Chris Rosser (Betaflight 4.4 Tuning Guide + Tips and Tricks for the BEST tune! - YouTube) in which he goes through some tuning process and made some additional changes on mine based on his info. I didn’t go through the process of the actual tunning via blackbox or anything, just used some of the values he suggested for dynamic idle and disabled some filters (although not the gyro ones just yet as he has on his video).
Flight time went up to 9 minutes and some change, on the 650Mah, which is 2 minutes increase from before. That’s a lot o flight time, which takes me back to what I originally had with the Crux with its stock 0.9 pitch bi-blades.
I’m quite pleased with the results and will probably be doing some minor changes again based on the video above, but I reckon it won’t affect to much of anything by now…

Couldn’t have so much good stuff without some tragedy in the middle right… lol

As I was midway through the second pack, I had a low speed encounter with a wall, and that was it, video was gone. I had the OSD just fine, just no image from the camera, so I suspected right away it would be something with the camera (hopefully).
Got back home did some checks and nothing seemed out of place. Removed the camera and tested on another drone just to make sure, and it confirmed the suspicions I had, the camera was damaged.
After having seen a post about something very similar, I checked the back side of the camera, a caddx Ant nano, and lifted the protective plastic to check the components and voila, a chip on the corner broke off and was just stuck, thankfully, to the adhesive of the plastic sheet.
Having nothing to lose and feeling luck I decided to take on the challenge and try to solder the little thing back. Before that though, I checked that if I pressed on the chip to make contact, the video would show again, so there was hope.
After several minutes of patience trying to hold the thing in place and having to redo it several times, it finally paid off, I got it working again. I was super happy that it did, this was by far the most challenging soldering I had to do given the dimensions of everything.
Only time will tell if this will last, but I’m taking the win for now and being grateful for it.

Here are a couple of pictures of it. The close up (sorry for the crappy photo) is after the job, the other one is when I had aligned the chip on top of where it had to be soldered:

Looking forward for some more air time tomorrow as this turned out to be a super fun drone to fly.


Flew some more packs outside with it today. Everything still working as previously.
Really enjoying flying it, nothing against the 1s version, but 2s really hits the spot for this one, everything is better (compared with the Crux). Wonder how 3s will be like, looking forward for that someday.

Going forward I’ll just try to fine tune a bit more and try not to crash it too much…

Yeah 2S is so much better than 1S when ripping. i finally resoldered my Meteor85 this morning and flew a couple of packs this afternoon. The ability to do a powerloop and not nosedive into the ground, is not to be underestimated. I can’t see me flying 1S anymore. Well i want to try a whoop with XT30 1S Lipos, just to see how much voltage sag I get.

I’ll still fly my crux on 1s for sure, its also fun, but not as much as this new guy.
The crux now is not for freestyle,given its reduced agility, atm it will be used to train some cinematic flying…