ESC high frequency fear uncertainty and doubt

[seagee]

ESC high frequency fear uncertainty and doubt

As the life cycle of DJI WKM & NAZA progress (and converge?) I see ongoing debate and more uncertainty regarding choice of ESCs.

Based upon discussions in the forums and my own experience with quad and hex (both 550 flat & 850 Y6) configurations to-date I conclude that for smaller craft, DJI’s own ESCs offer a high level of performance certainty at a mid price; however, on larger craft (>600mm) with higher investment stakes the issue is becoming ever more confusing with debates on Hercules II consolidated vs Hobbywing vs DJI and other ESCs which appear as rebranded HKs, not to mention the SimonK firmware reflashes and same-brand-label/different-internal-component pot-luck offerings.

There is some discussion on Hobbywing ESCs, a frequently mentioned brand which, as I recall, was initially recommended by DJI reps prior to DJI’s own offering being released. Hobbywing comes in various forms: Platinum vs Pentium (Funfly); and OPTO vs SBEC forms with some posters recommending avoiding ESCs with BECs due to superfluous EMI. Castle Creations newer Pheonix Ice and Pheonix Ice Lite have also now entered the arena as higher priced competitors although I note that these also contain SBECs. So what’s with the EMI here? I understand that EMI is reduced with a switching BEC but can this still be a factor in our builds?

Understanding the rapid progression over past months I’m keen on starting a general discussion on the current state of play re. ESCs in order to both help with my present dilemma of choice and help stay updated as builds progress, new offerings are released and more info comes to light.

In distilling, dare I say it – attempting to simplify all this info, I’m still not certain what would be best the ESC choice for my next build: a higher-end frame & component build. I am logically risk averse in my choice of ESC and I favor the idea of standalone ESCs vs consolidated boards at this stage due to the consolidated offering requiring a stack of two boards for a hex configuration. This would to some extent negate the simplification of integrating ESCs and leaves two redundant ESC ports.

My build is a Cinestar 6 frame with Avroto 2814 Short Shaft 770Kv motors and WKM FC. I currently have a choice of 40A HobbyWing Pentium (Flyfun) SBEC ESCs and DJI 30A ESCs. Which would be a better choice and what issues can I expect with either offering?

Colin

 

[daniel]

Hi,

my next build is a cinestar 6 with Avroto 770kv and turningy plush 40 amp ESC , with a MK FC using a serializer....

Not sure about the Avrotos, because the specs says 3-4 lipos, and MK motors, and quadrocpter motors are 2-6 lipos....

not sure if that would make a difference in performance, or if will affect ESC's..... im planning to use 4S lipos anyway.

i want this setup to be a heavy lifter.

i let you know how it goes...

daniel

 

[seagee]

Thanks Daniel

I'll be using 4S on the Cinestar 6 build. Might end up going with 30A DJI ESCs for starters.

Colin

 

[fritz99]

Hello !

I have already asked in several forums, but nobody can tell me which ESCs I can use for 5S LIPOS.
Herkules is too expensive for me.
Can anybody help me ?

Fritz

 

[ddmt]

Castle Creations Phoenix 35A can do up to 5S. Quite expensive though, 99 bucks each.

 

[Elliott000]

I just finished my ad-6 with axi 2814/22 motors.. I went with 30a funfly's so far all is well tho its only been a day of testing. I am running a tslrs transmitter and rx, any emi i may have is not affecting my signal and gps, ill b adding my 900mhz video tx tomorrow and will continue testing. I like this discussion, esc's were the most thought about part of my build

 

[jes1111]

And then there's the issue of position: on the arms, in the fuselage, length of wires (battery to ESC and ESC to motor), etc. My research has lead me to conclude that it's best to have the shortest possible run from battery to ESC, therefore mounting them in the fuselage. Also, I believe strongly in under-rating the ESCs - if your max amps at full throttle will be, say, 30A, then fit 60A ESCs.

Re: BECs on the ESC - I don't think they should be used at all on anything but the tiniest craft (and then only one of them). A dedicated BEC for the FC, etc. is the way to go.

There's no doubt that "flashed" ESCs do work better in this role. I gather the newest Castle firmware is on the money. Note also that OpenPilot is developing the OP-ESC - some feedback functions specific to OP FCs, but they should be a helluva good ESC for any FC.

 

[kloner]

what about the sponsor here, maytag?

I like castle stuff in my single rotor helis, but the HW pentium at least in the larger ones are the most desireable for fast switching in v-bar governor instalations..... Saw a post a while back from castle that they were working on firmware to make them more MR friendly.... did that ever get sorted out?

 

[supergravy]

what about the sponsor here, maytag?

I like castle stuff in my single rotor helis, but the HW pentium at least in the larger ones are the most desireable for fast switching in v-bar governor instalations..... Saw a post a while back from castle that they were working on firmware to make them more MR friendly.... did that ever get sorted out?

Yes, The newest FW from Castle flys fantastic. Previously I was using simonk flashed dys 30a with Avrotos and Naza controller. Now using Phoenix 25 and 35 escs which fly just like simonk or better. I was experiencing quirky motor startup with simonk and naza. The CC Phoenix esc's startup my ships with a vengeance - no stutter or delays.

So no need to fear or doubt, castle phoenix series are solid. And no whine either! CC gives you the option of setting pwm to 16hz or 24hz. They aren't cheap but for those in the US they aren't as expensive as people make them out to be. Current ebay listings show phoenix 25 for $49 and phoenix 35 for $65.

I think it woud be a mistake to choose dji 30a opto over phoenix 25. It is worth the extra money just for whine reduction alone.

 

[seagee]

I note that the Castle Creations Pheonix ESCs come with BECs. This is apparently not ideal. If the BEC capability is disabled does this completely negate the additional EMI. If so then what's the difference between using other ESCs like HobbyWing 40A Flyfuns and simply disabling the BEC; or as DJI recommends removing the live pin? Supergravy, please would you elaborate on why you think that DJI ESCs would be a mistake over Pheonix 25A - have you done a comparison between the DJI 30A and the Pheonix 25A? If so, what motors, payload & propsize?

Thanks,

Colin

 

[supergravy]

Hi Colin - In my experience speed controllers that come with BECs are the most common type out there, so if one were to require OPTO's your choices are more limited. I have used DYS 30A, hobbywing flyfun, Mystery Blue and CC Phoenix with my DJI NAZA controllers and have never had a problem with simply clipping or removing the red wire. I don't think EMI is an issue with the DJI controllers. So while a built in BEC isn't ideal, it isn't detrimental either. At least not in my experience.

As for my comparison with the DJI 30A optos, I currently own three F450's and one F550. All of these are used for fun flying or parts. Most of my attention, and all of my cameras now fly on Rusty's UAP1 frame and NAZA controller. When first built all of my UAP1's used DJI 30A optos simply because I knew they would work well with the NAZA. I put a lot of hours in with the DJI controllers and never had a problem, although I would often find the high pitch PWM whine almost unbearable.

I eventually tried the esc's listed above as it is in my nature to experiment and I wanted to lose the high pitch whine. It worked as most came with PWM set at 16hz, which decreased the whine significantly. All of the controllers generally flew similar to the DJI optos. Which is to say I never had a problem with any of them and flight was generally pretty good as long as it wasn't windy. All of the factory escs I had tried up to this point could be tuned to hover and fly great with no wind but all of them also wobbled to some degree when flying ATTI mode in the wind. This includes the DJI escs.

Then I got a hold of my first set of simonk flashed DYS 30A speed controllers. On my NAZA machines the flashed controllers provide erratic motor start-up, but they do always start, and then fly frigging fantastic. Suddenly it got real easy to adjust gains to perfection and the wobbles were completely gone. My quads are now able to fly steady in the wind and can descend like a smooth elevator. As an added bonus these controllers provide very quiet operation.

Last but not least, Castle came out with new firmware so I decided to try some Phoenix 25's. After a little testing, I bought more Phoenix controllers and will not be using anything else going forward. They provide all of the benefits of simonk without the motor startup quirks. And they come from a company that has actual reps helping with problems on the forums. As an added bonus, the phoenix 25's are the smallest and lightest escs of any I have tried. Despite this, they are also the coolest running.

So you can probably see why I think the DJI 30A optos would be a poor choice relative to the CC Phoenix or SimonK flashed HW's.

- The DJI's are somewhat expensive relative to it's hobbywing brothers so a poor value. I do understand they are a sure thing with the NAZA and very available though.
- The DJI opto's provide the loudest whine of any speed controller I have tried.
- All of the non-flashed HW controllers, including DJI, would wobble to some degree in even light wind and during vertical descents
- The castle products are relatively expensive but I think worth it for the reasons above. If you are on a budget there is always simonk...
- CC Phoenix provide wobble free flight, solid motor startup with NAZA and WKM, low noise, low heat, low weight and they enjoy a solid reputation

As for the details you asked about my setup. My UAP1's are all in quad configuration and range in weight from 1700 grams to 2100 grams without battery. I am using Sony Nex5n and Olympus E-PM1 for my cameras, both weigh 300 to 400 grams each. My AUW usually ends up being aroud 2800 grams. I use 4S batteries and Avroto 2814 motors almost all of the time. My staple props are APC 11x4.7, although I have also tried graupner 11x5, APC 10x4.7 and 12x3.8. Here is a picture of my favorite quad before I switched over to the Phoenix escs:


And here are some results:






Cheers!

 

[seagee]

Supergravy,
Many thanks for taking the time to respond in detail - very helpful and enlightening on the current state of play. If I were to get the CC Pheonix for my flat hex with Avroto 2814 770Kv motors do you think I should be looking at the 35A or 45A and do all Pheonix come with the 'new' firmware?
Cheers, Colin

 

[supergravy]

Supergravy,
Many thanks for taking the time to respond in detail - very helpful and enlightening on the current state of play. If I were to get the CC Pheonix for my flat hex with Avroto 2814 770Kv motors do you think I should be looking at the 35A or 45A and do all Pheonix come with the 'new' firmware?
Cheers, Colin

Your question raises a good point - Phoenix users will need to purchase their Castle Link USB programmer. It sells for around $25 and it is used to manage esc settings and update firmware. So far all of the esc's I have purchased were using older firmware (3.73) which required me to update during setup to firmware 4.01. Fortunately the process is very easy and straightforward. You install some software and then plug your speed controllers into the castle link one at a time to update settings and firmware. At this point you will want the "red wire" intact as it allows the esc to be powered by your pc's usb connection.

Once you have settings where you want them (mine are set to multirotor, low timing, low start power, pwm is 16hz) you can remove or clip the red wire, calibrate your transmitter throttle and put them into action. While having to buy yet another gadget sucks, the whole process does work really well and you will find there are a lot of people out there that are very familiar with these controllers and software if you need assistance. They are very popular with the helicopter folks, which is why I took the programmer for granted - I already owned one.

Word is that Castle is conservative in their amp ratings. I was a little hesitant moving from my various hobbywing/dji 30A escs to the phoenix 25's but I like the results. The phoenix 25's are running much cooler then any of the others I had tried with my setup. As the Avrotos are a 25amp motor, this seems to be a perfect match.

Now it doesn't escape me that you are will be using a very nice frame and will be lifting more then me. While I don't think this requires more then the phoenix 25's - I would consider the 35A controllers if I were in your shoes. Reason being that you might want to be able and use 5S down the road. The phoenix 45's would be way over the top for the Avroto's IMHO.

Hope this helps!

 

[vinnygogo]

how do you do your throttle calibration?

 

[Dewster]

I like DJI's plug and play design of their ESCs. I wish the company would make them for larger aircraft: 40 amp and 50 amp esc.

 

[supergravy]

how do you do your throttle calibration?

It is well documented by Castle so I will keep my answer to a minimum. You plug one of the esc's directly into your receiver and then adjust the throttle travel values in your transmitter until you get some prescribed beeps by the esc. The routine is different then the usual hobbywing but it works. Best part for me is that all of the controllers end up with fixed end points and the quads stay nice and straight when accelerating hard in manual mode.

I agree with Dewster that DJI's plug and play design is nice. There is a downside though. After plugging and unplugging my motors into the DJI optos three or four times I found that my 3.5mm connectors were fitting uncomfortably loose into the esc connectors. I eventually ended up cutting the male connectors off of the motors and put new ones on in order to get my secure connection back. This left me with minimal extra wire though so it will not be an option again. Perhaps my 3.5mm connectors are crap, I dunno. I have moved to a different bullet style connector on my "work" quads and like having this as an option.

 

[vinnygogo]

but what i was wondering: why would you adjust those endpoints with a dji controller that way? i wil explain:
first, when doing calibration(actually it is not calibrating your esc but adjusting your tx) you set endpoints in the transmitter to start it and have full throttle response.
then you plug them in your naza or wkm, and in tx cali you calibrate the endpoints of your transmitter. so IMO step 1 is useless, because no matter what endpoints you end up with at the end, you will teach the controller that that is 100 and -100 %. it is the controller wich controls en outputs the values, and has nothing to do with the actual value's in the transmitter. i think, keeping that in mind, the only thing you would have to do is set it to multirotor and fixed endpoints, and connect them to the naza or wkm.

 

[Dewster]

These are some great photos! I'll have to check out Castle creations esc. Do you use a wireless camera system to frame your shots?

 

[supergravy]

Hi Vinny - I follow you on this and think you are likely correct. I haven't done any experimenting with this as it was so easy to calibrate the transmitter that I have always just done it during my initial setup. While actually doing the routine I came to the same conclusion as you though. As a side note, my high throttle endpoint works out to be perfect at 100% travel. Only low throttle was adjusted (to 116%).

Thing is the CC/NAZA machines start up so well that I had no reason to question the calibration. Altitude hold is perfect at 50% throttle too. Now that I have been here on the forum typing all this I should probably test your theory. It wouldn't be much trouble to set my endpoints back to 100/100 and re-calibrate in the software assistant. It does have me wondering...

 

[vinnygogo]

i would be interested in your test. or maybe someone who buys new ones could do it this way?