Lumenier 2205 2400kv vs Emax2205 2600kv // Static vs In-Flight Current Draw

[Tmarter]

Currently building a 210 racing/acro quad (list of components below), and I had a couple concerns before I started bolting things up. I'm mainly stuck between two choices of motors that I have.

I haven't been able to see a live current draw while in flight before, as I've lacked an OSD to monitor it. Upon reading the current limits of all my components, I'm wondering if the current draw from bench testing (static thrust) these components would actually be far higher than an actual Flite Test (see what I did there ). I'm concerned about running too much current than what some of the components could potentially support safely...but I'm starting to wonder if I would have more overhead than I realize.

Have any of you seen a significantly lower current while flying than the numbers from a thrust stand, or test bench? If so, how much of a difference have you seen?

I'm on the fence between two sets of motors I have on hand, the set I don't use for this quad will just be a backup set.

I plan on using this setup for freestyle, but mainly interested in racing competitively, so it will be a fairly aggressive build.

Here's what I have:

FRAME
-MQC Fusion 210 (5" Prop Support)

BATTERY
-Glacier 4s 1300 45C (currently looking into graphene and/or higher C ratings)

FLIGHT CONTROLLER
-Betaflight F3 (built in PDB, OSD and Blackbox) Supports 100A Continuous, 140A-160A Burst, across 4 ESC's.)

MOTORS
-Lumenier 2205 2400kv (test bench results below)
https://docs.google.com/spreadsheet...uTwRPoSkif3bJF2V9jcobo8Eo/edit#gid=1127877024

OR

-Emax RS2205 2600kv (test bench results below)
https://docs.google.com/spreadsheet...I9JtoIXjKydGsAaVgPbavu6sg/edit#gid=1127877024

ESC's
-Lumenier 30A 32bit Silk ESC OPTO DSHOT 1200 (30A Cont. 40A Burst)

I also plan on carrying Full FPV gear with a 200mw TX, and a GoPro Hero5 Session, to give a ballpark for the total weight/payload, as I'm currently building it as I type this.

Feel free to offer feedback or recommendations, all considered & appreciated.
Thanks!

 

[French]

Nice looking build. The higher kv red bottoms will be more aggressive, but either set of motors would be good on this setup. Personally, I have not flown the motors head to head, but both are good. As you recognize, a 45C battery may be your biggest limitation with the red bottoms. All the other components can handle either motor fine.

Have you considered what props you'll be using? Those will play a significant factor in your amp draw.

 

[Tmarter]

Nice looking build. The higher kv red bottoms will be more aggressive, but either set of motors would be good on this setup. Personally, I have not flown the motors head to head, but both are good. As you recognize, a 45C battery may be your biggest limitation with the red bottoms. All the other components can handle either motor fine.

Have you considered what props you'll be using? Those will play a significant factor in your amp draw.

In the past I've really liked the response of the HQ 5x4.5 bullnose, which was on a 250 build. Later on, I picked up a Diatone tyrant and REALLY liked the 4x4.5x3. I'm Guessing the 210 will bridge the gap between the two, so I'm going to need to get a feel for how it handles.

From what I've gathered, the triblades with the red bottoms will scream...but I don't quite want pure unadulterated power, to the point where it compromises the control and smoothness. Let alone that, I'd be more concerned with how much current it would draw. Bench says about 30 amps, which is pushing my luck...unless it's less current when actually flying.

Nice thing about the F3 is the built in OSD with a current sensor, which I'm soldering up all the wires for now. I'm interested in finding out how it all runs, and how accurate it is.

 

[French]

A static thrust test is going to pull more amps than on a quad. I wouldn't be too concerned with the escs. Those can handle 40 amp bursts too.

You may want to also watch this video on calibrating current sensors:

Part 2 - https://youtu.be/mfM4EstS-Gs

 

[Tmarter]

A static thrust test is going to pull more amps than on a quad. I wouldn't be too concerned with the escs. Those can handle 40 amp bursts too.

You may want to also watch this video on calibrating current sensors:

Thanks for the input. Yeah I liked that those ESC's had a 10 sec burst of 25% of their power output...seemed like a good deal!

Joshua Bardwell seems to have a ton of really helpful info on this board. I was watching a couple of his videos earlier this morning.

 

[PsyBorg]

Joshua Bardwell and Painless 360 are usually the two places I seek help when needed first. Both have phenomenal videos and methods to get the information out to people.

 

[Tmarter]

**UPDATE/CRAZY EXPERIENCE***

I wish these flight controllers weren't sold out/back-ordered everywhere... I want to order a couple more for some backup builds.
Key Word: Backup.
Yes, something happened to the quad already.
I want to first recap on the build, outline the general scope of what was going on before the incident, and still trying to figure out what caused the issue, and what I can do to prevent every pilot's nightmare from happening again.

BUILD SUMMARY

Betaflight F3 Flight Controller

First off, I absolutely love this board over anything I've used before. In chronological order, each step up having more features I've gone from one 250 quad w/ KK2.1.5, two 250 quads w/ CC3D running OpenPilot, then recently i was flying a 180 and a 250 quad both w/ Naze32 Rev. 5 running CleanFlight.

Since the Naze32 Rev. 5 i bought around September '16, I wasn't quite keeping up with the newest tech in the hobby, as I wasn't able to afford a pretty decent build at the time. After some research, and luckily getting my hands on one before they sold out, this Betaflight F3 Flight Controller pretty much takes everything I used before, and kicks it to the curb. Having so much packed into the form factor of a small FC is such a huge plus, time saver, packing an amazing amount of benefits over any other boards I've used in the past.

I haven't messed with Kiss or any others yet, I'm still looking into them and doing research before I bounce on them.

Flight Characteristics
With the F3, I ran Lumenier Silk 32bit 30A ESC's running BLHeli_S, their own exclusive firmware, and Dshot600 (which is also a game-changer, since last September, OneShot125 was the latest protocol I knew about) felt way more locked in compared to anything I've flown before, and and the response was way faster.

However, I gambled on the PIDs before I even flew it, which is kind of risky... but the results were surprising:

Liftoff, an FPV simulator that I practice on ~2-4 hrs/day (2nd shift woes... and no daylight only fly on weekends), now utilizes Betaflight's PID loops, and now has updated physics, dynamic changes in flight characteristics based on weight calculation of your model from the components you choose, motors, props, etc... The best it can get for any multirotor simulator out there right now, especially since I also use my DX6 as a controller through the trainer port to my Pc's microphone jack (ask if you need any tips, pretty easy)... so the muscle memory and practice translates to the field very well in my opinion, and I'm not sugar coating that one bit.

I created a model that used a damn near identical setup to what I built... frame style and size, weight, props, motors, battery... I fine-tuned my PIDs in the simulator for HOURS until it flew perfect, flew it about 25 hours or so...THEN copied all the PIDS to my "real-life" quad in Betaflight, and took it for a maiden.

Butter smooth, and very responsive, almost identical accuracy in maneuvers, except that this new build was WAY more locked in. Blew my mind...

...for the whopping 1m 39s it flew. I landed it at 3.7v per cell, after seeing ~15.1v on my OSD. Way too short of a flight time for my liking. I started looking into ways to cut down on the weight, or increase efficiency without sacrificing too much performance.

What led to a near-heart attack...

For more efficiency, I couldn't really shave much weight off the quad even with different components, I'd only save maybe in the 25g ballpark, as it was already built as tidy as I could.

I was running HQ 5x4.5 Bullnose two bladed props to start out, but really wanted to run some decent tri-blades, as I liked how they powered out of corners, and they had a lot more low end torque. However, i wasn't sure that my motors would be the right application for that setup, with an already abysmal flight time.

Maybe I'm chasing a false hope for this setup, but is that flight time to be expected? What flight times do you guys usually expect for a high performance or aggresive 210 quad with a GoPro?

I ended up swapping the Emax RS2205s 2600kv motors for the Lumenier RX2205 2400kv, as those motors have multiple advantages in this situation. They weighed about 5g less per motor, which helps...and the lower kv would help in the low end, and also handle a heavier prop. While they aren't slouchy motors by the test results, and not near as powerful as the new Emax red bottoms, they are a lot more efficient. I figured I could offset the decreased power by putting on some tri-blades...which is what I wanted to run anyways. I was hoping that the Lumenier's could put me somewhere around the 3-4min flight times.

Upon switching out the motors, I also swapped my Lemon DSMX Satellite RX (which worked perfectly fine) for a new Spektrum SPM4849 Quad Serial Race Receiver w/ Diversity, making use of the dual antennas in the DX6, for better protection against a loss of signal, which i had never experienced...

Until I went to test it out.

I mounted up the new RX with the antennae at a 90* angle from each other, out the top frame piece. Went in to Betaflight CLI:
set spek_sat_bind=9

save

bound successfully at DSMX 11ms, solid orange light as per usual

Then, back to Betaflight CLI:

set spek_sat_bind=0

save

*to my understanding, this RX has a feature called "AutoBind"... while I wasn't sure if setting the RX to bind in Betaflight was necessary or not, i figured it wouldn't hurt at the least.

Double checked all my inputs in the Receiver tab, and honestly, no placebo effect, the response and update times seemed significantly faster than with the Lemon DSMX sattelite RX. I was feeling like this was a worthy upgrade, and was getting hyped!

I drove out to my spot, doing my typical pre-flight checks... turned on the radio TX, made sure I was disarmed (aux switch) Air Mode (as per usual), correct model, everything looked good. Checked the battery voltage, then plugged it in, everything A-OK. Looked for any signs of aircraft, all clear.

Hit the arm switch, and immediately the thing just shot up at full throttle like an Estes rocket.

I had absolutely no control whatsoever. Disarm switch did not work, and I chased after it with the radio on making sure it stayed in Disarm mode (like it helped already -___-), while trying to maintain a visual...and also trying not to $#!+ myself. I would have gotten in the car and set up my FPV goggles to track it, but I felt it was best to maintain a line of sight at this point, whileI could still see and hear it.

Soon, I couldn't hear the motors any more, from being too far away, and I thought it was a goner. It was almost out of sight after flying for about 25 seconds or so, which seemed more like an hour... then I saw the quad change it's trajectory...it stoped climbing, slowed, and then it started falling back, as it looked like the motors seemed to have stopped.

It barreled back from "God-knows-how-far-up", and I saw it land ~700 yards away from where it took off. running quickly, and hoping that the thing didn't catch fire. As I ran, i began wondering how much of the quad is still going to be left, what all was fried, etc.

I finally recovered it. It had landed in some talll-ish grass, and just missed a set of metal bleachers at a local football stadium by about 20 feet.
-Landed almost completely flat on all four arms, right side up.
-Didn't Break a single prop.
-Flight Controller LED's still on and looked normal.
-Motors weren't hot.
-ESC's weren't hot.
-Battery was lukewarm at best, no damage.
-FPV camera was fine.

The impact from the fall and weight of the battery did however break the top plate inward on one corner, just behind the second row of standoffs from the front. It also bent all the bolts that were threaded into the aluminum standoffs on the frame about 15 degrees forward meaning it had hit at a slight angle. Barely missing the lens of the RunCam Owl Plus. The new angle actually looked kind of cool

Checked the GoPro...I I had forgot to start recording. GAHHH!!!

I'm most thankful that no one got hurt or no property was damaged. Besides that signature X Mark in the ground from the point of impact. Sorry about the grass!

I have no words for how I managed to not destroy anything but the frame...which luckily is also a limited-lifetime warrantied frame by MQC, so I filled out a warranty replacement form, 20 bucks. If that's all the damage it got, they sure have a believer, they make one hell of a frame, and they use the good hardware for sure! Any run-of-the-mill stuff would have broke for sure. No Loctite was used on any of the threads.

First thing I'm doing is setting up Failsafe before I go out again, and may as well strap the thing to a brick before I take off! Hoping it doesn't fly away with it....

However, I'm still concerned as to why this loss of signal occurred, and I would very much rather this never happen again.
Any ideas?

Thanks for spending your Saturday morning reading my story.

 

[cranialrectosis]

Failsafe...

After any time you flash, take the props off and test failsafe on the bench.

I am fond of the 'fall out of the sky' failsafe. If the copter loses signal it shuts down, disarms and beeps. There is less risk to my homeowners insurance once the props stop spinning.

 

[French]

Wow. Crazy story and great write up. I wish that GoPro had been recording!

Always setup and confirm failsafe. Not only do I pick the drop option, I also set my failsafe default Aux switches to (disarm, buzzer on, led on, and angle mode [i realize this does nothing of the motors are disarmed])

 

[Tmarter]

Wow. Crazy story and great write up. I wish that GoPro had been recording!

Always setup and confirm failsafe. Not only do I pick the drop option, I also set my failsafe default Aux switches to (disarm, buzzer on, led on, and angle mode [i realize this does nothing of the motors are disarmed])

Yeah, I definitely hear you on that one. Unfortunately I learned the hard way this time around, but it's a lesson that will not be forgotten. Honestly I thought there would be some sort of default Failsafe already enabled, but again, my fault for not checking to make sure.

I actually wondered why I couldn't find any settings in Betaflight for this... then I clicked, "Enable Expert Mode". Then all was revealed!!

I'm also going to need to change a couple things to free up a mode switch too, and I'm only limited to six channels. Maybe I'll just permenantly enable Airmode in the Configuration menu, and remove the flight mode switch to free up the extra slot for the time being. Way more important to have Failsafe rather than having other flight modes that i never use anyways.

My only guess is, that the the quad (or really, anything) will pretty much default to max throttle upon a "loss of signal" (or who knows what happened), and that the only thing stopping that would be to have Failsafe enabled... would that be correct? I know some receivers also come with Failsafe, and the Spektrum satellites, like the Quad Serial Race Reciever w/ Diversity in my case, which does not have a Failsafe.

Another thing I'm very curious about now, besides wondering what exactly caused this to happen in the first place...I'm not necessarily blaming Spektrum by any means. But I've been reading as much as I can about FrSky's technology all day. I've had my newer Dx6 for about a year or so, and used an old Dx7 before that....but always been familiar with Spektrum. As with anyone else that already has a Radio, most people think, "Why have more than one?"

As these new features, tech and components continue more rapidly day by day (ie: new protocols, digital signals like Dshot compared to older anaolog signals which are now obsolete etc.) there's been something I've always overlooked, and that was the other selections of Transmitters and receiver protocols besides what I was using, and their advantages and disadvantages. There's a lot to understand, but I'm beginning to see the importance of knowing the differences now...and why each have their own applications. The fact being, the one you may have, may not have what you need.

It's a vague detail, but I've noticed that there's been a pattern with each new board I've upgraded to: At first, the only thing you could use was a Spektrum or other Satellite...Still about 6 years after DSMX came out, Spektrum's technology is not much different since then, besides an upgraded Radio and menu system 3 years ago, which I will be honest, is a great radio, easy to use, isn't cheaply constructed, and it's comfortable.

BUT that being said, other companies and protocols like FrSky have seemed to focus more on the technology side of things, and becoming more commonly supported (and even favored in both design layout, and public opinion) on most all new Flight Controllers (a specific example here would be the Digital Telemetry and the use of SmartPorts, and now it seems to me that Spektrum is slowly becoming the third wheel in the Multirotor game...which has been bringing TONS of new people into the hobby...A clear example of this can be as easy as looking up how much of a community is behind one protocol vs the other...not just about jumping on a bandwagon, but the point being that a larger community is also reflective of a larger amount of support for it.

In my opinion, from a business standpoint, the most strategic move that Spektrum could make here would be to consistently compete with the companies that are riding the business wave when it's coming in hot. Mainly because I would like to see a long-running key player in the industry be the one coming out with the the new tech...and I like the quality and feel of their newer line of radios, and the menus especially. I may not be seeing the full picture here...but for the multirotor game, that's how it seems.

Have any of you actually had personal experience with both FrSky Radios and Spektrum, with your primary focus on multirotors? Not only comfort, quality, accuracy and usability, but also how does the signal stability and latency/response times of each stack up to each other?
*I'm aware this is a long running topic...but I haven't found an informative answer yet, and still reading up on that topic.

For stuff like this, I would really prefer to go in to a shop and actually use it, and see for myself how the radio feels, but I'm beginning to presume that this battle is looking heavily weighted in FrSky's favor at this point...and I already have a Dx6. The main reason would be for the extra channels, the open source firmware for the radio, it appears to be insanely modular, and it's like half the price and twice the features, more than twice the channels I have now, and a large following. And not just contemplating this all because it "seems better than what I have"...but I'm starting to notice that I could actually make good use of an upgrade here, and it just seems more practical.

 

[PsyBorg]

I was on the same wave you are on now with my Devo 7. I ABHOR anything "Cookie Cutter" and I tend to NOT jump on the bandwagon. When it came to the Taranis it was hard for me to bend and take the plunge but I am soooo glad I did. I love the Devo 7 .. Super simple very well built and feels great in my hands. The Taranis took all of a day to get used to the different feel. The finer controls made a HUGE difference between the resolution change in the digital signal alone. It was like watching an 8 bit Nintendo game and then going to a dvd rom game. The learning curve was a bit of a shock but is easily over come the more you work with it like anything else I suppose.

Having the Taranis or the QX7 as a second radio will in my mind quickly become your primary radio if you do take a chance getting either.

 

[Tmarter]

I was on the same wave you are on now with my Devo 7. I ABHOR anything "Cookie Cutter" and I tend to NOT jump on the bandwagon. When it came to the Taranis it was hard for me to bend and take the plunge but I am soooo glad I did. I love the Devo 7 .. Super simple very well built and feels great in my hands. The Taranis took all of a day to get used to the different feel. The finer controls made a HUGE difference between the resolution change in the digital signal alone. It was like watching an 8 bit Nintendo game and then going to a dvd rom game. The learning curve was a bit of a shock but is easily over come the more you work with it like anything else I suppose.

Having the Taranis or the QX7 as a second radio will in my mind quickly become your primary radio if you do take a chance getting either.

I think I'm leaning more towards the X9D if I'm going to bounce on it. I'd really benefit from the extra channels, and I'm feeling a little restricted with the DX6 when it comes to extra switches in the Betaflight F3 Board...I could access my PID loops on the field through my OSD, have a proper Failsafe killswitch, start Blackbox logging, out of the box Telemetry.... and I could still keep my Arm and current mode switches.

Realizing that all of that is possible with just a different Radio is really making the cream rise to the top it seems. Never realized how much my setup is bottlenecked with only 6 channels...but then again, I wouldn't have expected I'd need more than 6 at one point. I can Remember saying to myself when I bought my radio, and just made a quick decision over a more expensive model:
"Ahhh...I won't need all those channels... I'll settle for the DX6"

Thanks for making me eat my words 2017.

Also, one thing I wasn't quite sure about when it comes to FrSky, is how well does the protocol handle heavy RF Traffic compared to DSMX? I guess they both use a similar switching method, but FrSky uses something called ACCT, is it essentially the same thing?

Going to be at Flite Fest East next month, and I'm actually wondering how most Radios and equipment perform when there are several hundreds of aircraft, FPV gear all within about a half mile and all going at once...

Wondering if there's anything to be concerned about in a place where there is a lot of RF in the area, and if there is anything that helps improve signal integrity or prevent brown outs from occurring.

 

[cranialrectosis]

For your FF 2017 interference questions, I'd start here:
http://forum.flitetest.com/showthread.php?27442-Flite-Fest-2016-World-Record