Servers by jDrones

MicroArduCopter, 3" props, Omnibus Nano, Success!


(Dave) #211

What’s in your “stack” ? The FC this thread is about, Omnibus F4 nano V6, is 5 grams and it includes OSD, battery power in and a couple of BEC’s for external devices. Paired with a 20x20mm 4in1 (I use an Ori32) and it’s very light.

What wicked1 said about the Ori32 is right. Some of the additional weight comes from 4 large current shunt resistors!


(Hugues) #212

I’d like a “complete” lightest stack including FC, 4 in 1 ESCs, PDB. Also it must have current and voltage measurements (hall effect would be perfect but shunt resistor will do)


(S) #213

Also about weight…
When building a small copter like this where you’re at a huge disadvantage with your prop efficiency(due to small prop size), I think it’s a good idea to always keep the weight in mind… For every component. Obviously the big ones like VTX, and receiver. But even the diameter of wire you use, the amount of solder you use. Your antenna choices. If something has connectors, it might be best to cut them off and directly solder. Battery strap choice. Whether or not to secure things w/ extra glue. Prop weight. Everything!
When looking at the weight of things, a gram or less might not seem like much, but when you consider it for every component and every material choice, it all adds up.


(Hugues) #214

yes. My first step in that direction is designing a 3" frame that is as light as the lightest I have seen on forums : about 12gr.


(S) #215

If you want to solder your own, I can offer advice for every component.
If you want a pre-made stack, you aren’t going to find much… Like we’ve said, the only 20x20 board supported by arducopter is the omnibus nano. There aren’t many stack choices out there w/ that particular board.
Then you jump up to the larger size FC’s, and a lot more weight.

Edited to say, the FlexRC 3" frame I’m using is about 15 grams. I’m mostly happy with it… The props are in the shot a bit more than I’d like, but it’s a compromise I’ve got to accept for now.


(Hugues) #216

I like the Omnibus F7 V2 for its vibraiton isolated IMU but it is much larger and heavier relatively to the nano.


(Paul Atkin) #217

there may be some very small light stacks in 20mm for arducopter on f4 chips - the issue is what it is you want to put on uarts. as soon as you start using a lot of additional devices - any f4 chips renders out as you need gps, lidar, RCin, telemetry out - a f4 chip based FC would usually have only 2 free uarts for you to use after you connect your radio. there are some exceptions like f4 omni FC - where radio can go to some other pin instead of occupying an UART.
that is why i built all my models on kakute f7 as it has a lot of uarts. matek now finally made new controller as well based on 765 chip that probably will be a new best choice, if it will work well and get hwdef file.


(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:
https://shop.holybro.com/kakute-f7-amp-atlatl-hv-v2-amp-tekko32-4in1-esc-blheli-32-combo_p1108.html

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: