My new quad - tarot 650 build

[tipsy trucker]

Good point, it's done it with the flysky tx and rx too though, even after calibration.

Do you know anything much about flashing escs? And, more to the point, their timing?

Where I bought them from had a screen shot of their programming, it's got timing on there with "medium" selected. I can't help but think if that's too fast for these motors they may be able to spin fine unloaded but have no torque.

I think they're effectively little bee escs, programmed with silabs - would I need a silabs connector and program or will generic ones read/write without any trouble?

[ched]

OK so you have tried the FlySky as well! I didn't realise that! I assume you set the tx back to pwm and used say the ai6B rx and plugged the esc into ch3(throttle)?

First check the FlySky tx has the end points set correctly (100% each way) in the rx then end points menu item. Then check in thh rx menu under display to verify that you are getting full travel.

Did you try the calibrate the esc via rx?
https://youtu.be/OOplk52R4no

I have never heard of esc not being compatible with motors, well other than voltage issue (motor or esc cant handle Cell count) or motor pulling too much current and burning out esc.

I think, and someone may well correct me, that BLHeli just adds communication protocols, I don't think it removes old ones but I also seem to remember that DJI Naza need 400Hz update frequency not 1000hz.

As for flashing that's tricky, now a days most f3/f4/f7 FCs support flashing through the FC. So you just download BLHeli suite and connect esc to fc as normal, usb to fcc and load the BLHeli suite and change parameters as you want or flash FW. I can't remember how to do it otherwise, seem to remember a USBASP adapter or an Arduino nano being involved.

Fundamentally you have a 3 phase motor  (3 wires in a Delta connection) being powered by an Electronic Speed Controller that, simplifying, gives out pulses that attract the magnets in the motor bell and cause it to rotate a little, the esc then pulses then next wires and a little more movement. Do this many times a second and the motor spins.
The FW basically gets a control signal and converts that into pulses. So Say DShot600 (600,000 bits/Sec) is a digital protocol so is just given a code for 0% all the way to 100% (2048 Steps) rotation speed. The older stuff was PWM (Pulse Width Modulation) which relied upon the width of the top vs bottom of a square wave (well sort off).
So as far as I know the FW on the ESC should still support the old PWM. Which I think is what Naza is using. But I am not sure about speed of PWM control signals. This might help or confuse
https://oscarliang.com/esc-firmware-protocols/

So check tx/rx, manually calibrate esc and if still issue I would get a servo tester and see if that lets the motors run at full speed.

[tipsy trucker]

Cheers fella, I think I've covered most of that sadly

I found the problem when using the taranis, I then connected the signal (and ground) wire directly to a spare ch on the receiver (pwm), run through the calibration and tried it - same result

after checking and rechecking lots of settings, including the tx and naza and confirming that min and max throttle were where they should be and re doing the sticks calibration in naza, still doing the same thing. At that point I did some poking around with dvm and didn't find anything unusual


This morning, I tried with the flysky and ia6b after running the esc calibration again (I did also check 100% throttle) but still the same.

So now, I'll order the servo checker - I think I've already disproved this to a certain extent but it's cheap enough to try.

I'm also going to order a usb interface for blheli suite and download the suite.

My theory is that these escs worked fine with the higher kv motors (980) so there may just be something in this timing thing - it's a very different motor after all; if it's charging each phase a little too early, maybe it'd lose a lot of torque but still be able to reach max rpm without any load 

other than that, I'm a bit lost - if the esc's are communicating too fast, I really don't understand why it didn't show up with the 980kv motors too 

[ched]

It does seem a bit weird. Only thing you can do is try each component as separately as possible.
I know it's probably more work but have you any of the old motors to try? Just swap one and see if that performs correctly.

I assume that when you followed the video above it all calibrated correctly i.e. not using the naza?

[tipsy trucker]

I did yeah, I don't think you can do it through naza

I have got the old motors, I'll admit I've been doing my best not to have to un-solder then re-solder though. The servo tester should come tomorrow so I'll see what that shows up for a start 

[tipsy trucker]

And it flies.... Finally!


https://youtu.be/99xGcusJHkQ

Appologies for it being at 90degrees, I couldn't find a way to rotate it

[tipsy trucker]

So, the next thing I need to figure out is gains:

Although it looks pretty stable in the video, most of the time it wasn't - in about a 10mph wind it seemed to be having a hard time stabilising itself and lost altitude when it yaws

Can anyone offer any advice about how to tune the gains please?

[ched]

Sorry me again 

On my F450 with Naza V2 (lite flashed with V2 FW) I took a win10 tablet into the field. I then upped the gains a bit at a time and took off 'wiggled' the sticks and watched how it responded, landed tweeked then repeated. I was mainly trying to get it to respond a bit quicker to my stick inputs as it seemed sluggish. If you up the gains too much if will oscillate after a quick change of position. So just tweek them down a little.

The basic rule for gain tuning is too low will exhibit "wobbles" or loose handling, gains too high will make the craft oscillate rapidly. Using these two characteristics as your limits, you should be able to find a happy setting in between.

I assume that your Naza is running V2 Firmware? If not it won't hold position very well.

10mph winds are quite a bit, especially as the large props can't react that quickly to speed up or slow down. I would play with the gains a bit and see how you get on. There are no 'standard' gains as each aircraft has different motors, esc, frame, props, weight etc... You just have to play 

[tipsy trucker]

That's about as much as I could find out, I'd like to understand what's going on but I've no problem with the trial and error way really. Hopefully we'll get some reasonable weather tomorrow

[ched]

DJI Naza gains are a bit weird. I believe they tried to make things simple as when they first came out Flight Controllers like KK or CC3D  or Naze32 where about and they ran software with PID loops. These are Proportional, Integral and Derivative feed back loops.
Basically PID controllers are trying to get the system to a set point as quick and accurately as possible. The problem is that PID loops are quite difficult to get right, if you make it too responsive it overshoots the setpoint and pulls back and undershoots etc. Not sensitive enough and it is too slow to react and never reaches the setpoint. It is a juggling act to get each of the 3 terms (PID) to be at the best as they interact with each other!!! But getting it right was very difficult so DJI Naza simplified things by just having a limited set of adjustments called gains.

Roll on a few years and for small quad we are using F4 or F7 FC with a lot more processing power and the software is so so much better. The default PIDs will allow virtually any quad to fly reasonably and quite a few people never even bother to adjust PIDs. Year ago without adjustment it would have been almost impossible to fly!

So Naza is simple and just needs a bit of tweeking. Oh in fact I think you can actually assign a gain adjustment to a rotary control on your tx. So you can tweek very easily in the field.
I think it's called remote gain  and you can set your rotary control to X1 or X2 (might have to use cables between rx and FC.
Have a google on dji naza remote gains, that should give you some clues.

[tipsy trucker]

I'll have to have a look at the current settings in the morning; I've a feeling I might have turned all of the gains right up to see if it had any effect on the motor problem.

I'll let you know how it goes anyway

[tipsy trucker]

Quite a bit better today, despite the wind being stronger. I turned all of the gains down by about 30% and then a couple back up a touch.

It's not bad now but I think I might be able to get it even better on a still day

The radio signal seems much stronger with the new gear and battery life so far is quite encouraging  (though I'm not being very brave with it yet).

I think you might be right though ched, I may turn to something small and fast for fun

[ched]

I started a few years ago building a QAV250 (ZRM250) kit from Aliexpress. I built it no problem but I couldn't fly it to save my life. I used to manage about 10 seconds before crashing even in stabilised mode. I sort of gave up, but then swapped it for a F450 (plus a few quid) with a Naza Lite (flashed to V2). It was so much easier to fly I added gimbal etc. It was great, I bought some very cheap Box goggles (£30) and WOW I was hooked. I was mainly flying in GPS mode but it was enough to improve my eye hand co-ordination.
After almost a year, as I didn't get much chance to fly, I bought the components to build a Martian3. This March I moved house and found a football field to fly on at the weekends. I started learning in Rate/Acro mode and it has been difficult for me. I guess as I have never really played computer games so my fingers are not great  Anyway I can now fly round my field without crashing and even get through my FPV gates.
So winter is now here  So I was looking to learn more indoors. I watched youtube vids and there are some small (70mm across) 1S & 2S quads that can be flown indoors. So I ordered a Mobula7 hopefully it will arrive before Christmas. It should be great indoors on 1S battery and 2S outdoors.

Anyway, keep tweeking and you will get it to feel how you like. Camera platforms are great to get views of things that are not normally accessible but small fast quads are also great fun and a bit of an adrenaline rush. Racing is on another level. Racers have unbelievable control and megga fast reactions but it's great to watch.