Servers by jDrones

MicroArduCopter, 3" props, Omnibus Nano, Success!

(Hugues) #218

What is the weight of your kakute F7 stack (including 4-in-1 ESCs if any ?) ?

(Paul Atkin) #219

it is not very light.
whole build with no battery is about to 200g. 1500mah 4S lipo is 250g or so, so, it pushes those motors a bit much.

stack i used was this one:

it is not only stack that is heavy, it is motors. plus lidar, gps, esc8266 board, r-xsr, foxeer camera - it all adds up.
motors are brotherhobby T1 1407 3600kv. i could have used bigger ones, i think, it would be better. something with bigger stators that can still mount in the 1407 format.

(Dave) #220

Hi Paul-Are you happy with that Matek GPS module? I’m planning on building a plane with a F405 Wing and that looks like a good option.

(Paul Atkin) #221

Yes, i like it. It works well.

(Paul Atkin) #222

a bit annoying thing happend - owl frame oscillated and propelled up in alt hold, i automatically killed motors and let it drop down, as i usually do - as armattan frames are pretty much indestructible.
not so much about owl frame… $80 out of the window, its 2mm carbon came apart in 3 places on both plates. pretty whimsy quality carbon, i must say… i wish they made it from 4mm one, as i do not care much about weight - it would be better to have it sturdier.

so, ordered now their new gecko from armattan, will see how will that work out. and ordered a omni v6 nano board, so, will probably get to its guts soon. do we still have an issue with logging not working on it? is there an internal storage on it for logs, at least, or nothing at all?

(S) #223

I’d recommend their 'beefcake" frame. Thick carbon. Good layout to keep the camera forward of the props. Has room for 2 short stacks. He’s using better carbon on the newer production, too. (I’m sure your owl frame is old production… he’s been out of stock on those for a while). I want to try their lighter frame that is similar to the beefcake, the ‘skydiver’, but they’re out of stock.
Otherwise, I am super happy w/ the komori frame… although it’s a light 2mm carbon one, too.
The ascent x 3" is at least 3mm carbon.
FYI, Komori has a little bit of the props visiable in the video, but not much. The ascent3" has more… (like, 4x3 is prop free, but the rest of the wide 16x9 has props in it, if that makes sense). I keep my camera almost flat, though… If you angle your camera, it the props might drop below the picture.

Flex warranties some of his frames… all the new ones. Not sure about the owl, but you might want to check their website.

Oh shoot, as soon as I hit reply, I remembered you need 30x30 mounting… I don’t know for sure which frames support that.

(Dave) #224

Nothing at all for logs unfortunately.

(S) #225

It does have 16meg flash, doesn’t it? So once logging support is added, we can at least log a flight if we want.

(Dave) #226

Yes, it does have that. A mission file can be stored. Dataflash logs would be great. I have come to rely on them heavily for flight tuning, it’s a much longer trial and error process w/o them. Live tuning helps.

(Paul Atkin) #227

I ordered both another owl and gecko. I think owl is the only one that has protected 3" props and 30.5 stack mounts. Will see. So far i did not really like how owl came out. Too heavy and too many vibrations.
Yet for indoors model props need to be isolated.

I think may be i can superglue old owl to new owl carbon. But it will get very heavy this way

(Paul Atkin) #228

i did put owl back together, in a form of an FPV flying brick. :slight_smile: as heliderect guy refused any form of a warranty on a frame - i superglued old dmaged frame to a new frame i bought and got 2 4mm owl plates. new owl also came with aluminum stands - so, now it is indeed an indestructible beater with protected props. perfect gift for my daughter and safe. fact that it does not fly fast is not important. :slight_smile: models total weight with no lipo is now 310g. crazy heavy for 3" model but those 1407 motors manage to fly even with a 200g 1500mah battery - only lasted 4min drawing 11A to lioter, but, it flew, and, thanks to beefy frame vibrations went all the way down from what i posted above - 40-50 area all the way down to 8.
so all in all i am quite happy. works now with yaapu7 script - so i removed esp8266 from it. still have a lidar and gps, it all worked out ok. now i wait for 850mah lipo to come to see how it will fly with 100g less to carry.

(Paul Atkin) #229

i later decided to split upper plate in half keeping it at the 2mm thickness. it is just too heavy. good idea of an a frame, but, it is not working well in the 3" prop format. it probably would be very good in a 4" format with a 16xx motor instead of 14xx motor… still, as a toy for a child who like to crash stuff and fly a bit erratically :slight_smile: - it works.

(Hugues) #230

For those who like an OWL 3" frame, you can 3D print them with a similar design I made (30,5 x 30,5 mount spacing)

And the corresponding STL files:
MicroQuadBottom.stl (580.9 KB)
MicroQuadTop.stl (926.1 KB)

And printed in ABS, it weighs 43g:

(Paul Atkin) #231

It is a good design but lower motor plate should be 3mm thick minimum. 4mm carbon i got now feels good. 2mm was lighter but too flex.

i just flew it with 850mah battery, with it the total weight of new owl is 380g and flight time is just 4min of a calm loiter. not ideal at all. if i take off upper plate it improves quite a bit - but - kinda defeats the purpose of such design, to have protected props. kinda pity to take it all apart again now, not sure, i will need to think about it, i like how it all came together, but, in this 3" format it is quite challenging.

double glued 4mm lower plate now i think is about 50g, upper single 2mm plate is 22g but with all the aluminum posts and bolts it gets close to 60. may be i should have used 4100kv motors instead of 3600kv, but i do not think it would improve flight time, most likely quite opposite.

(Hugues) #232

I agree that if your AUW is close to 400g , it is not compatible (too heavy) for a 3" class. Nowadays, with classic 3" frames such as IHF3, or beefcake, or Komori, most 3" racers remain under 200gr battery included (lightest ones with battery are around 120g, 87g without battery and full HD camera installed). Obviously the OWL frame is not to be considered a racer frame but rather a “truck” drive for slow cruising around the house and is adapted for kids (thay can bang it against the walls).

(Paul Atkin) #233

That is the exact point i wanted to make it, for my 8yr old daughter to learn to fly it. Just thinking now what to do to get flight time at least 7-8min from 4min. I probably take off camera for now. Really wanted it to be an fpv but, it is not critical. It is just a heavy frame. But, a safe frame and, now, pretty much unbreakable, a big plus, as when she flies my rooster i have to swap props after almost every other flight. :slight_smile:

(Paul Atkin) #234

I still not sure how it can be under 200g with battery. 850mah is 100g. Frame is 40g.
1407 motors plus wires plus 4in1 esc is 90-100g. Plus FC, plus camera plus VTX… Unless it is not 14xx motors used, perhaps, and a 3s lipo? May be…

(S) #235

Yeah, as I said earlier in the thread, my copter posted above (1st post) is about 95 grams w/out battery. But that does include everything else… HD video, antennas, gps, etc…

You’ve got to make the weight your primary design concern…

Paul, I’d suggest switching to a VTX that uses ufl antenna connectors. Shorten your excess wire length. (I see some wire kind of bundled up in your stack) I’m not sure what else though… Maybe take off the rangefinder. Use smaller gauge battery wires.
But otherwise, you’re right, 14xx are heavy… unless they’re the 1402’s on 2s, which are awesome!. Motors are pretty cheap at this size… You might want to think about switching to some smaller higher kv motors… although batteries aren’t exactly cheap, and you might not have 2s… (I have modified 1s and 3s to 2s, so that’s an option, too).

I’m not lacking performance at 2s… I can go 100mph for 4-5 minutes, or hover for about 11-12 minutes… Normal flights are 6-7 minutes.

-also, 2 blade props are lighter and more efficient, so a win-win.

(Paul Atkin) #236

Hi, you probably meant 1102 motors? it is possible, but, not sure. i really want to figure out how to make this specific heavy owl frame work. which may not be possible, but, will see.

(Ricardo Maroquio) #237

Hi, everyone!
I did my MicroArduCopter 3" props using Pixracer R14 FC, EMax RS1306 4500kv motors, GF3025 propellers, mRo uGPS+Compass, HAKRC 15A 4x1 ESC, custom CF frame, custom 2S Sony 18650 3A VTC6 battery and I got 21 minutes of flight. BUT… I had issues in calibrating compasses, so, I had to disable the internal compasses using the new parameter COMPASS_TYPEMASK and calibration is okay now using only the external compass (this is a new tip to avoid “error compass variance”! :)). My problem now is when I fly in stabilize mode. It does not stay still when flying in stabilize mode even inside a closed environment without wind, and the most strange thing is that it seems to stay flying inside a imaginary polygon of ~2m “radius”. Can PID settings be responsible for this? If not, do you know another possible cause, excluding PID, mag and accelerometer settings? I’m flying in stabilize, so, GPS and compass are not being used…
I’m posting here because my assembly is very close to this. :slight_smile:
Thanks in advance for any tip!