(09-Apr-2022, 03:18 AM)amped_fpv Wrote: It does not handle high winds very well.  I generally try to fly when the winds are less than 15 km/h.  Part of that is because it's so lightweight, but also because I purposely don't have very a agressive PID tune to maximize efficiency.

Yeah i understand, thats why I am curious how some commercial companies managed to make powerful sub250 quads. Kudos to UAVTEK, I am impressed how they managed to maintain long flight time (40+mins) with insane wind resistance (35knots, 45knot gusts) on their sub 250 BUG nano quad. I might be wrong but seems like their setup is based on 2S 18650 with 1105/1106 motor using 3/3.5/4" triblade props.

Hi amped,

I am a little late to this thread, but I really like what you have done.

That frame is awesome. Good Job.

I am interested in iNav for my Rescue Quad build, but I have never used and have
no knowledge for it yet. So, I am curious about your experience with it. I saw that 
you had some initial issues. I would like to hear more about your thoughts on iNav.
What you like, what you don't, etc. Thanks.

About motors, I used BrotherHobby VY 1504.5 3950KV motors on the Unsanctioned-1 build.
These motors with HQProp T5x3 bi-blade props and 2 M2x7 prop bolts weigh 13.1 grams
each. That is 52.4 grams for 4 motors with mounted 5 inch props. I also have these motors
on a 4 inch build, the Katana-LR4, and really like them. I had NO problem with the wind
on either of these builds. The motors are smooth and powerful. On the one hand, I was a
little surprised how well they spin 5 inch props; on the other hand, I knew how well they
did spinning 4 inch props. 

(09-Apr-2022, 12:27 AM)versus Wrote: Great concept. Looking forward results !
Btw, I have few questions:
1. Is this AIO board compatible with Arducopter?? If not, is it possible to stay sub250 by using ardu compatible boards like Kakute H7/Matek F405 MiniTE with separate 4in1 ESC?
2. How does this build handle winds? (I m really impressed and curious how some companies managed to make sub250 mil. grade quads that resist 60km/h winds and 80km/h gusts like UAVTEK Bug nano)
3. Have you considered new HGLRC 1603 2800kV motors too ? (Dave_C quad designer claim that its wider stator handles better 4" props; more efficient than 1404)

Hi Versus,

Although I have heard of Arducopter, I haven't really seen anyone do a build with it. I am curious what advantages 
the firmware might have over Betaflight or iNav. What does it do, or do better, than these other firmwares??

Thanks for mentioning the HGLRC 1603 motors. The weight is listed at 12 grams which is the same as the 
BrotherHobby 1504.5 motors that I have used. I am always up for more power at the same weight. Looks
good for a 5 inch build...or maybe even a 6 inch.      I just ordered 8 of them from AMAZON. 

Yeah, I know, I am a bit eccentric    I figure that I might need a couple of spare motors just in case...
so, if 2 spares are good then 4 are better. If I don't need any as spares, then I have enough for 2 builds.
Crazy, Right, but that is just me 

You may, or may not, know that my focus is on getting the most that I can from a sub-250 gram quad.
Even though I may diverge from that for special purposes like rescuing a downed quad, I basically live
in the sub-250 gram world. Also, I like flying high {above 350 feet - 106 meters} and just cruise easy.
My overall preference is a 4 inch quad, but I really like the 2.5 inch for just playing around and in smaller
spaces. The 5 inch quads intrigue me and I have built 2 sub-250 gram craft, but it is a challenge to keep
a build of this size below 250 grams and still having a decent amount of power. 

Anyway...Thanks...  


[Edit]  Here is a stator volume comparison; for what it is worth.

1404     ====   615.71
1504.5  ====   795.17
1603    ====    603.15

I haven't yet determined nor found how stator volume effects efficiency or performance, how to
factor that in with other motor specifications, nor how to effectively use it.

Quote:iFly4rotors

Although I have heard of Arducopter, I haven't really seen anyone do a build with it. I am curious what advantages 
the firmware might have over Betaflight or iNav. What does it do, or do better, than these other firmwares??

I never tried Arducopter, but from what I've seen that its #1 when it comes to missions, integrating bunch of sensors and autonomy. Its literally giving you ability to simplify your quad to level of commercial drones, to such level that you forget that you are flying, launching and landing, but rather focus on finishing your task eg. rescue, surveillance, mapping etc...
I was sold on ardupilot "throw launch" lol 

Quote:...Thanks for mentioning the HGLRC 1603 motors. The weight is listed at 12 grams which is the same as the 
BrotherHobby 1504.5 motors that I have used....

Its listed here as 10grams.
https://rekonfpv.com/collections/new-arr...less-motor

Quote:I haven't yet determined nor found how stator volume effects efficiency or performance, how to
factor that in with other motor specifications, nor how to effectively use it.

Idk either :/ I am unfortunately not long in this hobby, nor engineer.

There is no correlation between size or width and efficiency.

Motors typically have 20-30% peak efficiency curve. It depends on load. **If you are cruising using 140g thrust per motor, picking best motor is picking one that reaches peak efficiency as it pushes prop to make 140g thrust**

If anything, wider bell has more momentum and thus takes more energy to accelerate.

I found you can get a bit more flight time by having very UNresponsive PID. Less energy spikes torturing battery. BLHeli higher timing and higher PWM can help a bit too.

But biggest factor is obviously prop. 5" or 6" CF prop you can get insane long flight time with just 15xx motor... but obviously sacrifice everything else.

Hi Versus,

Amazon lists the weight as 12 grams, but HGLRC does list the weight at 10 grams.
Amazon probably has it incorrect, but I will only know for sure when I put the motors on the scales.
Sometimes manufacturers list motor weight without wires...when they do this the actual weight is
often more. I have run into this in the past...where the actual motor weight with wires is more than
what is advertised. I guess this is ok, but it makes comparing motor weight challenging at times. 
For me that is ok, it is close enough. I will see when I receive them. Just a note, that 13.1 grams 
is the actual weight of the 1504.5 motor with wires, props, and prop bolts measured on the scales.

Also, the 1603 motor is not available at many vendor sites. I have only found it at the HGLRC site and
{much to my surprise} on AMAZON and in limited supply {that is another reason that I ordered 8 of them}.

I have added the HGLRC 1603 motors with a link to the HGLRC site to my Parts Guide <-- Click to Download.

------------------------------------------------------------------------------------------------------------

Hi Roman,

Yep, there is always trade offs...as with everything from cars to boats to quads. You just can't have both ends
of the teeter totter up at the same time. It seems that the extremes of the pendulum swing from pure efficiency
to pure hi-performance. So obviously, if you want to go to one extreme, then you sacrifice the other. Most people
go for somewhere in the middle, but not always. I am sure that the stator volume has a place somewhere in 
all of this, I just don't know where at this point. 

Personally, I tend to bias efficiency and "Fly Time" over performance, however, there are times and situations 
where I may deviate from my preferred path to accomplish a defined goal or objective.

Hey all, finally had time to make some quick posts.
Between work, life, vacation and bad weather, I haven't had much time to focus on posting and building.

Here's a few photo's of the current iteration.

Things are progressing well now, but I had some growing pains with INAV since this was my first go at it.

A few comments on INAV that might help first timer's like me:

1.  Make sure there's an INAV firmware target for the FC you're planning to use!  If you want to do RTH with INAV you need a GPS and Compass.  I new this, so I ordered a JHEMCU H7 AIO that had SDA/SCL pads and a baro and I thought was going to be great, but there wasn't an INAV target for it.  I ended up learning a lot, because I managed to compile my own custom target for the board, but in the end I didn't end up using it.  I got all the UART's working, but I couldn't get the current and voltage readings to work correctly.  Turns out there was an issue with the INAV ADC source code and some H7 FC's, which has now been corrected, so I could probably now compile a working target, but I've already installed that AIO in another build.

2.  Read the documentation and watch lots of videos.  If you're used to Betaflight, there are definitely a few differences that you'll need to figure out.  Pawel and Painless360 have a lot of great videos.

3.  Take baby steps and don't be in a rush... in my excitement I rushed things and ended up crashing quite a few times.  My recommendation is; Hover test then fly in acro mode, then angle mode, then test altitude hold, then test position hold and only then test RTH.

4.  With Betaflight I usually test pitch, roll and yaw while still on the ground at idle speed before I hover.  I tried this with INAV and it didn't move.  Turn's out there's some sort of throttle threshold that you need to exceed before you have control over pitch/roll/yaw.  So for example, you need to throttle up past 10% before you have control over the quad.

INAV RTH is awesome.  To see the quad land itself within 3-4' of were it was armed is pretty cool.

I haven't had a chance to do any long flights yet, but I did a PIDToolbox "basement tune" and I think it's tuned fairly well.

I kept the tune as "tame" as I could for efficiency.

The problem I'm having now, is I have a low frequency frame resonance that I can't seem to get rid of.
It's very consistent at 50Hz and it seem to be causing bad oscillations during hard coordinated turns and sometimes during throttle punches.

Now, I really don't expect to ever actually do agressive moves with this copter, but I'd still like to mitigate this issue.

I've checked it over and over mechanically and don't see any obvious issues.  I secured all the wiring and tightened all the screws.
At one point I thought maybe it was coming from my long antenna, so I taped the antenna's down to the top plate, but nothing changed.


One thing is, I don't remember these oscillations happening when I first built it, so now I'm wondering if I've got a rough motor or two.
I've manually run the motor's up without props on the bench using INAV, and I don't see any crazy bad vibrations.

That said, I did have an incident where I accidentally disarmed and did a free fall from 110m up.  
I landed in some dirt/mud in a field and somehow didn't really break anything, but I'm wondering if my motor's got hit and out of balance from that crash.

So my next desperation move is to replace all the motors.
These T-motors are really nice motors, but they're a little notchy (I really don't know if that has any relevance once they're energized and spinning), so I thought I would try the Flywoo 1404 3800's, even though Ecalc say's they're less efficient and heavier.

Well, I received the Flywoo motor's and they're even heavier than I was expecting.... they're 1.5-2g heavier than the T-motor's, so it would add at least 6g to the build!  I can't do it!  At least not yet.
So I'm going to just replace with new T-motors and see what happens.

I hope I can get this solved, because the weather is improving and I really want to starting logging some flights!

BATTERIES:

I assembled a 3S pack using Molicel 18650 M35A cells.
It weighs in at 140.9g
       
I bought a small rechargable spot welder on Aliexpress for $35 and this was the first time using it.
It worked great.  Much cleaner than soldering wires across the cells (and a little lighter too).

Huge shout out to Roteron, who came up with the idea to elimiate the balance leads and only attach them for charging (using magnets).
Absolute genius!
       

I planned on trying out the Home Alone batteries as well, but unfortunately I missed the nickel strip and accidently touched the spot welder to battery casing and actually put a pin hole through it!  That was a bit scary.. the battery started oozing so I put it in a container with salt water.  Not I've got a toxic soup that I need to dispose of somewhere...  In hindsight, I probably should've thrown it in some kitty litter or something.
I only bought 3 batteries so all I can make now is a 2S pack.
       

I haven't given up on this project yet!

Some updates....

Finished build photos attached...

After a crash I rebuilt with all new motors for fear of one or two motors causing vibrations, but doing so didn't improve the frame noise.
My frame design has some bad resonance at 50 Hz on Roll and 70 Hz on Pitch so I had a difficult time tuning, but I managed to get it to a useable state.
It's still a little twitchy on hard turns, but I've tuned it for efficiency, not performance, so it's fine for easy cruising in low wind.

I've completed a few test flights now.
The longest out and back so far is 11.5 km and the longest endurance flight total distance is 30 km in 39 mins.

       

Hoping to attempt 13+ km in the next few days, weather permitting!!

Fingers crossed

Awesome!

I'm guessing your antenna tower at the back is contributing significantly to the frame resonance. If you can find a way to stiffen that up it will help things considerably.

(31-Aug-2022, 07:49 PM)V-22 Wrote: Awesome!

I'm guessing your antenna tower at the back is contributing significantly to the frame resonance. If you can find a way to stiffen that up it will help things considerably.

I actually had the same thought back when I first started troubleshooting the resonance issue. So i tried stiffening it and I went as far as temporarily removing the mast and taping the antennas down to the top plate... Still had resonances at the same frequencies.

I'm sure it's still not helping matters, but it's to the point that I don't want to mess with it any further. Especially if it means adding more weight.

Appreciate the tip though V-22!

Maybe battery mount then? I just noticed it's only a rubber band. Is there a non-slip pad under the frame so the batteries can't move?

Hi Amped,

Nice build.     

I also like the "Handyman Special" launch pad.
Now, that is something that I might build.

(31-Aug-2022, 10:48 PM)V-22 Wrote: Maybe battery mount then? I just noticed it's only a rubber band. Is there a non-slip pad under the frame so the batteries can't move?

Yes, possibly... I haven't played too much with that, so that could be a potential source.
I did print some TPE strips that are on the battery (aka home brew battery pads), but they're pretty minimal.

Thanks!