Size limits of NAZA vs WKM?

[ewr]

I searched first but didn't see anything so sorry if this is a super dupe!

I am building a custom 900mm Hex with 4830 motors and 15x5.5 props. 16AH 6s battery, GP H3 and small 700tvl camera for video along with UHF and OSD goodies brings the AUW to about 10 lbs (4.5Kg).

The thrust capability of the prop/motor combo is theoretically around 18Kg and I know this is a seriously over propped/motored frame for the AUW, so you don't need to yell at me about that (this is an experiment for a large diameter, high speed, high wind hex with minimal AP use and payload requirements) so I just wanted that extra thrust available for high speed/wind "resistance" use, not extra payload (although it's nice to know I CAN lift heavy things if I wanted)

I guess what I'm getting at is....I already have a brand new NAZA-M w GPS that's been sitting around from a cancelled F450 build that I'd like to use for this project. I know DJI has warnings not to use the M and use the WKM instead for anything over 650 size and really heavy stuff...but my thinking is that although my hex is larger than recommended diameter, it is very light weight and wont ever have much of a payload, so I'm hoping the M will suffice.

Any thoughts on this? The whole build isn't going to cost much and won't have a $$$$ camera/gimbal setup like most of you have on this size/power Hex so I'm not super worried about lawn darting it a few times to see if the NAZA-M will work...just looking for anyone that has done this before.

Thanks for reading!

 

[blushoes]

i cant say conclusively, but here are some things i have experinced.

so far, my best most stable craft has been a dji f550 running naza FW 2.02
it has hobby king 2215J 900kv motors and turnigy 25A esc.

it was my first foray into multirotors with intention to go into AP. a cheap test set up.
and my best performer to date.

I have also tried WKMs on droidworks AD8HL and S800

I then moved to foldable hexas, the tarto 650.
i figured that if my little f550 could carry a pseudo dslr (those large-ish panasonic lumix that looks like a dslr)
then my new hexa with T-motors and T-motor escs could carry something bigger.

at first, i started the new hexa on wkm. but it just was sooo unstable. wobbly flight. even had one just do a flip
for no apparent reason during hover . the hexa had no payload yet.
i read that wkm doesnt like light disc loading so maybe that was the case. i tried 2 wkm units and couldnt get
them to fly as steady as i wld like.

then i tried naza . seemed much more stable, but not as stable as my first f550.

then tried strapping the Av200 gimbal and a nex7 on it. that payload (excluding batt) is about um..1.7kg i think?
naza was all over the place on trying to take off. just kept keeling over.

its not conclusive, but thats what i have so far.

 

[ewr]

Thanks for the detailed reply, blushoes!

Only sucks that your details aren't good for my project lol! I am wondering if that issue could be fixed by adjusting the gains on the NAZA-M...I know the default gains are a lot different for the NAZA vs WKM so maybe if I start with gains more towards the WKM default setting it will be different. I'm still a NAZA noob so maybe not. I know a lot of people will just tell me to stop trying to avoid using the WKM and just get it but I still can't justify the price for a non AP platform....1.2K is fine for carrying $5000+ gimbal/camera payloads but for a GoPro and UHF gear it's pushing it. The money isn't an issue and I'll get one if this just fails into the ground.....just trying! Thanks again though blushoes and I hope I can play with the settings and make it work.

 

[kloner]

flipping over is too low of gains on a naza. you would never expect any flight controller to work with (default gains). I fly a 12lb 800mm hex with a naza, flies 60 mph and it is butter smooth. I've also got a wookong on a jib and they both look the same, great. wk used to have alot of extra features but now there pretty much the same minus the ability to add waypoints.

 

[ewr]

Thanks kloner....back to being optimistic! I am a NAZA noob.....could you possibly post your gains for that Hex or gains you think I should try first since my setup should weigh within 1kg of yours.... I've read the manual three times and think I will be able to figure out the adjustments but would be nice to see some numbers I can watch for or try out!

thanks again

 

[kloner]

usually it is 120-160 on the manual gain row and 85-100 atti. if it oscilates at all wa wa wa wa then too high, if it's tipsy and slow to correct it's low

 

[ewr]

Thanks kloner.

I was reading the manual and it recommends 140-140-100 for a 330mm then 170-170-150 for a 550mm...so If I have a 900mm I would think the gains should be way higher than 120-160, no? sounds like they should be in the 200's if the increase is linear....I'll start with 150 across the board and see how that works.

Thanks again

 

[kloner]

my 800 hex is 160 and my skyjib is at 100..... they both sound and fly the same but ones naza and ones wk

this isn't a number you nail by guessing, you fly it. put the top rown on one knob and the atti on another and dial it in

 

[swisser]

you would never expect any flight controller to work with (default gains)

With respect, I completely disagree. I have a DJI 450 quad which has varied in weight between 1 and 2.5 Kg and a big heavy hex and each have been run with Naza and WKM controllers at different times. Both fly perfectly reasonably with default gains. I have never seen a properly built MR (quad, hex or octo) with a Naza or WKM flip because of incorrect gains. Gains are about tuning the flight characteristics, not the basics of taking off, keeping right side up, and landing again. With both the quad and the hex I can set up remote gains on the transmitter, go from minimum (about 60?) to maximum (about 200?) and they both still fly reasonably well; I've got video of it and you'd be hard pushed to tell the gains were being changed, at least not whilst it's just hovering and without a view of the sticks. When the gains get too high it might produce a rapid oscillation, but that's about it for flight stability, otherwise it's about how snappy it changes direction, or tries to hold attitude.

 

[ewr]

I don't have adjust on the fly capability with the setup I'm using for this...so it's going to be a long "fly, land, connect to pc, fly land, connect to pc etc etc etc" project lol

thanks

 

[kloner]

Every rig has a number.... depends on esc's, motors, props. Some rigs are 100, but if the gain is low i have seen em try flipiing over, when there too high, ive seen em act hypersensitive to any little movement that makes cameras shake, instability, etc.......

I would never make a remote gain so open....... it'll wind up getting to the wrong end of one of those scales...... if you set it to 100-160 with endpoints, you can chase to 160 then reset them if you needed more. once i get my numbers where i like em, i dissable the remote gain part so they can't be changed innadvertantly. a digital trim is best so the knob can't accidentaly be changed. it will act like a handfull with the gains set wrong