'sup guys... Is Ronin still around these parts? This was actually my second build. I was looking for something largish/stable to fly in the open field at work on windier days. I was hoping for durability so a friend over on rcgroups helped me make up some tpu mounts. Not the lightest thing ever but IIRC, it's a bit under 250g with a 4S 850:





That's a Flywoo GEPRC Stable 20a and vtx I got on sale somewhere. The motors are Xing 1504 3900kv... It's pretty much built, set up and almost ready to fly... but I was never able to get the FC to see the HM elrs rx. I flipped rx/tx just in case, then replaced the receiver. Still no love. I did update betaflight so maybe a resource configuration issue? I got frustrated, bought a Crux3, and stuck this in the corner...

So: Do I bother getting this guy going as-is? I could use some input from you guys with more 4" experience. Does the motors/props/weight balance look usable? I know it's a bit heavy. Or...



Those are some BH 1507 4150kv motors I was originally toying with.  Ultimately, I decided the FC was unlikely to survive and moved to the lighter 1504s.  That said, I have a JHCMCU 40a 4in1 and a HM fyujon (lol) 20mm vtx/rc combo sitting here... So I guess the real question is: Do I rebuild with the larger motors and electronics and put the 1504s on something else? I think it would still be under 250g with a 4S 720 pack but I feel like those sag quite a bit.  Anyway, what says the gang?

The iflight 1504s are not particularly powerful motors (mine have no notchiness at all) but seem to be pretty smooth. I have a set on a 3.5" cinematic flyer, maybe you will get a little more power with 4" props, but depending on the weight of your setup. I imagine you will enjoy the 1507s more, I have some 1408s (similar stator volume) on a 4" and that flies with some oomph. But if you already have them mounted, why not give them a try and then decide.

Hi Drumgod,

I guess it really depends on what type of performance and flight characteristics that you
want to get from this build. Before giving up on it, I would fly it just as it is. From my
perspective, it looks like a nice build. In fact, pretty close to my Katana-LR4 build.

I would consider getting the RC link working. Someone knowledgeable with ELRS
should be able to help with that. 

The spec sheet for the Xing 1504 3900 indicates a max continuous current of 18.96 amps
so the 20A AIO board should handle them without blowing up since the 20A rating is per
motor.  

My guess is that it will fly just fine, be a nice cruiser, and a decent proximity flyer. 

That said, if you want a hot-rod, Acro Stunt machine, well, it may or may not live
up to that. It just depends on what you want it to do. For me, it would be fine.

Later, iFly 

my experience on a 4inch freestyle build with that kv was a limitation on rotorchoices, i didnt had the hq4043 around, they might be good choice possibly.

heavy weight requires some rotorstiffness, the gemfan 4023 doesnt match on high load, but it needs to be as light s possible therefor also low pitch to gain benefits from that kv.

what topspeed would 4200kv give on a lightweight build, i believe in theory it might be way over 160mph xD

adjust esc settings, lower startup, increase timing. limit the max rpms by motoroutputlimit. these can be options if you come into trouble between battery and motorperformance and motorheat.

depending on your flightstyle, a lightweight battery and tve gemfan 4023 could match either, but that might limit the versatility in use.

about the esc, even 4200kv might stay around 20a, i would trust a decent 20a esc - i believe there is no need to care about on 40a.
jhemcu aio might probably gain benefits with a condensator. there seems allready one beatyfull mounted in a 3d print :-)

and aditional, the tuning direction will be lower the default values. the power to weight will be very high, specialy on tht kv the acceleration either..
i would suggest to decrease the pid values by multiplier slider, about 20% to get sometving useable or start adjusting at 30% less.
a battery killer xD i would like to try

Hmm. My current flight style is not what it was when I built this. Then, I was looking for a wind-resistant, freestyle capable cruiser. I guess a still am, I'm just hoping to continue to shift more in the freestyle direction. If anyone cares to check it out, here's a pack that pretty well represents my flying:

http://www.drumgod.com/fpv/clip122.mp4

That's from a TP3 3S 1303 5000kv. I had been flying a couple 4S Crux35s around until I killed them. I have three ready to go now, waiting for me to get around to getting elrs up to date on all my equipment... This 4" feels quite a bit bigger and heavier than my usual rides though. lol. Heck, I mainly fly 1S.

Yeah, the GF4023 props are a considerably thinner and lighter than the HQ 4x4.3x3. They do feel to me like they might be a limitation with the current build. Perhaps the 1504 guts would be better suited to a really light 3.5 or 4" toothpick? Now that I think about it, I believe that 20a FC/VTX and maybe even the 1507s and HQ Props were used in the... GEPRC Dolphin?

If I went to the JHEMCU board I'd gain 8M blackbox and 5V 2.5 amp to directly power my peanut cam. I use an in-line batter adapter I made with the Crux35s. The electronics would probably be a touch lighter, offsetting the larger motors a bit. I could use the ceramic cube antenna on the fyujon to shave a little more, but I don't know if it's worth the possible range loss. I had thought to use a motor limit when I was first considering the 1507s. The spec sheet says 30amps on 3x4x3 so the 40a should be over kill if I go that route though.

Just mulling over options...

Hi Drumgod,

Nice video. As a reference, that flight is just a bit more aggressive than my normal flights.
When I do proximity flying, it looks about like how I fly except maybe a bit faster and 
without the spins and little maneuvers. That said, I generally fly at an altitude that is close 
to 400 feet (about 120 meters) where the sky is wide open as I like to just cruise and watch
the scenery. I like a craft that is smooth, stable, and handles like butter. The more stable 
the craft is, the better I like it. Yeah, the ACRO stunt guys might say it is like flying a tank, 
but to me it is more like flying a real plane...like a real pilot. 

I will add that my focus is on sub-250 gram quads and I prefer a 2.5-inch for just playing
around and having fun. In the sub250 category, 3 and 3.5-inch seem to be best for a 
performance quad because it is challenging to get the "preferred" hi-performance
characteristics in a larger quad and stay within the weight range. So, it depends on 
where you want to be with the weight. 

Ronin's frames were designed specifically for the sub-250 gram category so they are
biased towards the frame being lighter and geared toward long range rather than heavy 
duty, hi-performance, ACRO. One of the key features of his larger (4-inch) frames is the 
dual position mounting setup which allows one position for the FC and another for an HD 
digital video unit. I like his frames as they work for my style, however, I would likely 
choose something different if I was into all that hard core ACRO stunt stuff. Heavier 
motors put more strain on the arms when "pushed" and then there is crashing at full 
speed. 

Personally, I would keep the Ronin build as a nice cruiser and build a quad specifically for
hi-performance if that was where I was heading. Again, start with the weight category. 
Do you want to stay under 250 grams or do you care? 

If you would like to stay in the sub-250 gram category, then you might take a look at my
Build Methodology - Sub 250 document. Even though I am still working on it, the core
information is pretty much all there. 

Later, iFly  

your kind of flight looks like your kv does give more stick resolution than used.
more acceleration and topspeed doesnt help if not used, they does decrease the ability for handling.

to much power for a spot to fly makes it more difficult and therefor limits the progress and fun.
i bet you would use about 15% throttlerange on the 4inch foe the same flight like seen with the tp3. from 35% up to 50%, more would go more agressive.
to fly same kind, but receive better handling, more throttlesticck range for that spot; i would suggest to set a throttlelimit of 65%. release the limitation does allways feel natural, flying an overpowered quad can be annoying.

i just saw these trees and their gaps, to push the throttle and take the gap with a mouvement in it :-)
that would be fun, good or lowered throttleresolution could make that more easy :-) 4200kv on 4s would allow to shoot it throw the gaps with speed, but that will go expensive for sure xD

for the kind of speed and acceleration i saw, the gemfan 4023 might match well. until realy agressive direction changes or topspeed, the might provide a better handling and response


if you like to go extreme about performance, a 4inch with motorsize around 1408 and kv around 3600kv on 4s - less than 150g - might be about the dolphine settup.
depending on the spot used with 550mah- 850mah 4s - that would let 5inch racequads look slow in some cases ;-) on a thight technical track, 5inches doesnt slow down aswell, they fighting their mass while 4inch shines with nimbleness and response and therefor also in efficiency and power consisdency.

Thanks guys. I'm leaning towards keeping it as-is. For now, anyway. I need to dig up my notes and BF dumps for this FC and see where I left off. I seem to recall I couldn't flash elrs to the RX through the FC either.

@iFly4rotors: That's a great look at the requirements of sub250. Thank you for sharing it! Keeping it under 250g is preferred, though not strictly necessary. lol. I rarely fly more than 50' up or 100 yards away.

@hugnosed_bat: I'd be flying faster if I was better. :-P I understand what you are saying. I do fly a bit faster with the 1S stuff and bounce off of max throttle regularly. Some I believe because I have 5:1 flight time with them, but also because they are just plain easier to handle. On the TP3 I'd guess I'm using maybe 3/4 throttle max, if I get rowdy, but I'm not really sure. Are you suggesting I try a motor limit on the TP3? That will get me increased throttle resolution in the range I am using? That makes sense... My goal is to increase my skill to where I *can* utilize the full performance. I guess you don't just buy an F16 if you want to learn to fly one. Limiting power, to be increased in steps as skill increases, sounds like a good approach. Alas the TP3 has gone squirrelly on me again. Maybe I'll make a post on that while I'm sitting here...

Well, I'm up late sick so...

I verified the wiring on the HM ep1: rx->tx2 and tx->rx2
I dumped the existing configs (BF 4.2.11) then upgraded the FC to BF 4.4.3.
I reconnected BF and applied the custom defaults.
I dumped the new default configs, set a few basic things and ensured orientation is correct.
I configured uart1 for irc tramp and flipped the serial rx switch "on" for uart2.
I confirmed Serial via UART and CSRF settings.
I fired up the elrs configurator, configured for the ep1/2 target and built successfully.

I was not however, able to successfully flash the rx. It failed with this log:


When connected to usb, the rx orange flashes every second, looking for connection... After around 18 seconds it goes to a fast flash... Wifi mode. So it looks like rx is powering up fine... I tried two different usb cables as well...

Per the documentation referenced in the error:

Quote:No serial data received.

Esptool didn’t receive any byte of data or a successful slip packet. This error usually implies some kind of a hardware issue. This may be because the hardware is not working properly at all, the RX/TX serial lines are not connected, or because there is some problem with resetting into the download mode.

Okay, I reconfigured for the uart rx on the early betafpv aio in my Babytooth... It successfully built and flashed it to elrs 3.3.1 on the first try.

Hmm... Is there a wire length limit between FC and RX? I'd guess they're around 2.5" long.

Okay, I figured it out... The ep1 rx is entering wifi mode in 18 seconds.  That's not long enough to "build and flash" the firmware.  If I watch and plug in the drone just before it actually flashes I get:



and I'm presented with a "force flash" option.  Unfortunately, I can't just hit that. The drone is back in wifi mode and if I unplug it the force flash attempt fails with an undefined device... even if I plug it back in before it flashes again.

The solution: Use wifi update. I just flashed it to elrs 2.5.2 which should allow me to bind it to my tx16s I'm tired. More tomorrow maybe...

Were you trying to flash 3.x? I have problems with passthrough with 2.x and was told the newer configurators no longer support it (but should work with 3.x). I use wifi flash and it works fine. Maybe try flashing via wifi.

Much progress today... What I didn't have access to in the past was a windows machine. I now have a newer laptop I can put some of this drone hobby software on... I'm still trying to do most of it on my desktop in linux though.

For proof of function I have been upgrading my 1S babytooth and tx16s at the same time. Both are now at 3.3.1 as well. I flashed the radio, via wifi, with 2.5.2, then the "repartitioner", and then 3.3.1. The babytooth (early uart betafpv board) went straight to 3.3.1 via pass-through from linux. That all went well and the babytooth binds to the tx16s automatically via passphrase. (I can set up my fleet of crux35s now.)

Per the HM EP1/2 docs at expresslrs, I flashed the rx in the MKII to 2.5.2 first, via wifi. Once it was on 2.5.2 it had a normal 60 second connect window and I flashed it to 3.3.1 via pass-through from linux. That worked... but it didn't exactly. It didn't bind to the tx when it powered up so I tried to reflash it. I couldn't reflash it so I connected to it via wifi again.

I was greeted with a 3.3.1 configuration screen with a crap-ton of fields. There was an "import config file" dialog at the top and a "save config file" button at the bottom. I hit the save button, hoping it would apply some sort of sane defaults, and it restarted into the standard interface I was expecting to begin with. Because I had no idea what was up with the config screen, I then reflashed it, via wifi, to 3.3.1. This seems to have worked correctly and the wifi interface is as expected. It still, however, will *not* connect to the tx. I also tried setting the passphrase from the wifi interface, but no luck.

So it's sitting here again, ready to go, accept I can't get it to bind... My memory was a little off. I threw it on the scale and it's coming in about 252g with an 850mah.  The tpu accessories are my favorite part about the build, but I suspect I could move to a lighter antenna setup and get it under 250g.  As-is, it's 227g with a 720mah.

3/4 sounds good, 25% spare sounds nice

1s is an other animal, i was refering to the perfromance of 4inch 4s 4200kv comoared to the flightspeed in the video - just on the other settup, there would be so much spare speed which will it make handle less good or more difficult on that speed.
the flight with the tp3 looked good.

for 1s we have the othet issue or general on ultralight quads with small motors -suffering on topend.
a throttle limit makes often sense for ultralights but for same reason "stick resolution".
on ultralights, specialy 1s with biggblades, the upper rpms can go innefficiency and slow at thr same time, 90% throttlr can be slower/less power than 60% throttle - all can go into heat and just inneficiency. it can be benefical to npt touch a n upper throttle level to stay fast.
it would make sense to explore throttle limit on the tp3 either, but it did look well. its more difficult to find the sweetspot for the power and handling than the sweetspot for power and efdiciency. optimize the tp3 could be more difficult.

on 4s 4200lkv 4inch, you will feel the need for throttle limit easy: if you struggle to use the throttle smoothly, if you are fighting between throttleuse, alot of corrections - you will get benefits by a throtte limit.
from my experience, that settup is responsive, most pilots will get into trouble if used in tight space.
i love powerfull quads and are used to drain them, the trick to make an over responsive quad into controll is to ask for even more response from it, drain the battery enough does limit the throttle/responsivness in the end.
there are settups not able to fly at 25kmh, 1mm throttle change, can be more than 25kmh difference on a very powerfull quad on low throttle level - its not possible than.

If your transmitter is ELRS 3, you should be able to flash your RXs directly to 3.x firmware. Sorry if I confused you, I flash to 2.5.2 as my radios are still on that version. If you are on ELRS 3 and not able to bind, go into the RX wifi page and double check that you have model match turned off and also set your binding phrase there. I think @snow mentioned sometime back that the passphrase set by wifi takes precedence over the one set in firmware in 3.x or something odd like that.

Thanks Hugnose. I appreciate the insights. The TP3 definitely has faster ranges I'm not able to utilize well. If anyone is inclined, this is a more practicey pack a few days earlier. I'm playing around and trying to get my speed up a bit into where the TP3 feels really responsive. lol. It's just a bit faster than I'm able to fly comfortably. I think I can get there though. Skip to 1:00:

http://www.drumgod.com/fpv/clip121.mp4

I'm itching to try this MkII. I'll keep plugging away and let this hang out here for awhile, see if anyone has input. I'll make a specific post in the radio area if this thread isn't fruitful... I don't see why it isn't working. The tx16s radio side is good on elrs 3.3.1. The EP1 RX is at 3.3.1 as well, but it won't connect. The betafpv aio at 3.3.1, set up at the same time, connects fine...