New Z15's woeful idea of horizontal

[MombasaFlash]

How precise can one expect the Roll axis to be at its default horizontal setting - default as in 'FPV Mode'? Having finally shelled out for the whole S800/WKM/Z15 package I am severely less than impressed.

After the initialisation dance the Z15 Pan axis settles in all sorts of places and then slowly works its way around to face roughly forward ("roughly" not 'Exactly"!) and the Roll axis settles a degree or two to the right of vertical (when looked at from the front) and then slooooooowly starts to move to the centre but overshoots, finally settling at a full 1° off the vertical (or horizontal if you wish) to the left.

This is not really a problem for two-man flying because the horizon error can be adjusted with the camera Tx. But for One-Man flying that needs to stay in either Mode 1 or FPV this is lousy because the Roll axis cannot be adjusted manually in either mode - at not in the latest firmware. The result will be a permanent horizon lean.

I did not anticipate a problem in getting the unit replaced, as it is clearly not calibrated correctly and there is no facility to adjust such parameters within the Z15 software, and have been dismayed by DJI's response that 1° error is within acceptable limits.

W THE F !

Unbelievable.

So what about everybody else's Z15's? Do they all settle at a true and level 0.0° horizontal (after their initialisation dance and subsequent warm up/ settling in period) or are you all putting up with wonky horizons?

Here is the video. I was not going to make it public but DJI's ridiculous attitude has incensed me so it is now on show.

 

[redridinghood]

Wow you seem to have one of the good ones. Mine shows considerable more drift than yours. I am using a perfectly balanced 5N with an old Wookong and V2 MC. I find that the older firmware is more forgiving and has less glitches.

 

[MombasaFlash]

Is your Roll axis manually active in Mode 1? Although auto compensation is available in Mode 1 & 3 my Roll can only be moved with Tx input when in Mode 3 i.e. fully auto. I have 360 Tilt and limited Pan in Mode 1 but no Roll.

I am wondering if this is just this firmware version (WKM software: 1.34, FW: 5.16; Z15 software: 1.4) because I have heard that Roll IS available in Mode 1 in earlier FW.

 

[BorisS]

How precise can one expect the Roll axis to be at its default horizontal setting - default as in 'FPV Mode'? Having finally shelled out for the whole S800/WKM/Z15 package I am severely less than impressed.

After the initialisation dance the Z15 Pan axis settles in all sorts of places and then slowly works its way around to face roughly forward ("roughly" not 'Exactly"!) and the Roll axis settles a degree or two to the right of vertical (when looked at from the front) and then slooooooowly starts to move to the centre but overshoots, finally settling at a full 1° off the vertical (or horizontal if you wish) to the left.

I can only comment on the pan, and there is a significant difference between is performance in my apartment and what it does on the field. After trying to calibrate my AQ mags in my apartment i understand why.

Concerning the default fpv mode i am also not happy with that ! The pan lagging behind a little doesn't make me happy ! Especially for a one man show its only semi usable, and the biggest problem for me is that it doesn't correct short-term disturbances on the yaw axis. For me this all doesn't make sense since the zenmuse nicely locks in the pan axis in 360 degree mode what ever position you set it to. I don't understand why they don't use the same method for the fpv mode and lock the nose to the front of the copter or give you a switch to set what you think the front is !

This is not really a problem for two-man flying because the horizon error can be adjusted with the camera Tx. But for One-Man flying that needs to stay in either Mode 1 or FPV this is lousy because the Roll axis cannot be adjusted manually in either mode - at not in the latest firmware. The result will be a permanent horizon lean.

I did not anticipate a problem in getting the unit replaced, as it is clearly not calibrated correctly and there is no facility to adjust such parameters within the Z15 software, and have been dismayed by DJI's response that 1° error is within acceptable limits.

I have seen a couple zens here in vienna and they perform differently on the roll axis. I stayed with one of the first FWs since i wasn't impressed with the results the other guys got ! In general though i am pretty happy with its roll axis leveling from actual footage from a flight. If you find the time again try the same test but outside away from any electrical installations inside and recalibrate the compass once one !

Hmm doesnt the third mode the one with the restricted pan axis, have the similar behavior on the pan axis like the FPV mode ? but gives you the possibility to correct roll if necessary ? But than again the pan is not performing that way we would need it.

Boris

 

[BorisS]

Is your Roll axis manually active in Mode 1? Although auto compensation is available in Mode 1 & 3 my Roll can only be moved with Tx input when in Mode 3 i.e. fully auto. I have 360 Tilt and limited Pan in Mode 1 but no Roll.

I am wondering if this is just this firmware version (WKM software: 1.34, FW: 5.16; Z15 software: 1.4) because I have heard that Roll IS available in Mode 1 in earlier FW.

wait let me check i have one of the first gh2 zen FWs

Boris

 

[BorisS]

okay just checked, just to get no confusion going, since i have no clue what the different modes are called.

1. 360 degree mode 2 man operator, roll can be controlled obviously.

2. Reset or FPV mode, roll can not be controlled.

3. Restricted pan mode, I can operate roll and and tilt.

Boris

 

[redridinghood]

1. 360 degree mode 2 man operator, roll can be controlled obviously.

2. Reset or FPV mode, roll can not be controlled.

3. Restricted pan mode, I can operate roll and and tilt.

Same here

 

[DennyR]

Boris if it didn't lag behind in FPV mode how could it stabilize, that band of movement is just for that purpose. Works for me every time.

 

[MombasaFlash]

This issue was first discovered with test flights at the airfield - after the compass had been calibrated. Reviewing the subsequent video revealed the wonky horizon. This is not a result of powering up indoors.

So, as everyone else appears to have Tx control of the Roll in both modes 1 & 3, it seems that the latest firmware has disabled Roll Tx commands. How bloody stupid.

If it were possible to tweak the Roll over to remove that 1° off-axis Roll I would not be quite so upset but I cannot without going to the unrestricted full auto mode - and then unwanted stabilisation of the Pan axis is also enabled.

Can one go backwards with firmware? As far as I can see the whole process is automated via internet and that once you have moved forward you cannot go back. Dammit. But ..... if it is possible to go backwards does anybody have an earlier version that does not nobble the Roll?

Other than the remarkably smooth stabilisation I think this Zenmuse is a pile of crap in its current form. Of course the various camera restrictions are one thing but the biggest omission is the almost complete absence of control over essential parameters. One cannot limit end-points, set centre points, disable individual axes or any number of the various tools provided with the Picloc, you just have to accept what those chinese berks have pre-configured.

After all the years of unpleasant surprises with gear that doesn't perform it pisses me off no end that I have been had once more. I hereby swear further allegiance to Holger and George and bollocks to the chinese sods.

 

[MombasaFlash]

Three hours of delicate effing around have solved the Roll error. There is a way to adjust the horizontal angle mechanically. It is definitely not what DJI want you to be messing about with and probably not for the faint of heart. It is very much a trial and error process and invariably the whole thing will get totally out of whack at some point. However, stick with it and the horizon can be brought to dead centre - albeit with a small and customary bit of gyro-ambling around centre within a range of around 0.5°.

Immediately in front of the Roll Axis motor is a small window that permits access to two grub screws ('set screws' to Americans). Releasing these allows the whole Roll/Tilt tray to move independently of the motor spindle. After a LOT of trial & error that tray can be brought to dead horizontal.

As I have said when this issue became apparent, this is a Quality Control/Factory Setup issue and they have not done it properly. I also adjusted the Pan Axis the same way so that it now faces forward. In the process I discovered that some bright spark on the DJI assembly line has stripped the thread of the housing for one of those two grub screws so that only one of them tightens properly.

When I took the stock blades off to verify balance only one of them required no further balancing. The sandpaper marks on the undersides show that balancing the blades is part of the DJI setup procedure but again, they didn't do it properly.

They no doubt have genii inventing their stuff and reliable guys in R&D, but the assembly line jocks are the monkeys being paid peanuts and it spoils their products.

 

[FerdinandK]

Did you already fly with the Zenmuse (a bit faster and a with a bit of pan)?. I would expect you see things different after your first flights.

Edit.: Just read that you already flew with it, so it shall be ok then.

With all DJI Products you can go "backwards in time" by installing the old assistant software (deinstall the new before).

best regards

Ferdinand

 

[MombasaFlash]

Thanks for the "TimeMachine" info.

A couple of things I didn't mention before, just for general info.

These axis center points (notice I spelled 'centre' the US way there ) are not determined by the angle of the gyros. I first tried swivelling the Z15 IMU in the opposite direction to the angle of lean but it ultimately made no difference. The tray would of course move but would then resettle back to the same off-centre position. The centre points are determined by motor position and it is this that allows the camera tray to be turned on the motor shaft to adjust the tray to horizontal. The motor is obviously remaining in the same place that it has been told to do so.

Weather permitting it now needs another couple of flights to determine whether or not these mechanical changes have truly solved the horizon issue.

The other thing is that a quick trip to the DJI site revealed a 0.18 FW update that has fixed the Roll issue so that it is now enabled in 'H.Free' Mode (with the restricted Pan).

 

[ChrisViperM]

I had the same issue like you with the horizontal line...out of the box the Zen was also not pointing straight forward when stick was in the middle. Strange enough the whole assembly (Zen with mounted Nex-5) was not in balance when no power was applied. After some diggin I found this vid:

After following this vid I balanced the damn Zen for hours, but it was still not right. It was perfectly balanced in the horizontal and vertical line.....but didn't help. Then I flipped the S800 zu one side 90° (like in the vid at 12:50) and realized that in this position all my balancing was worthless...it was not even close to be balanced. So I started all over again, but this time I made sure that all three axis were in balance....fired that bastard up and everything was perfect.

Strange thing I noticed later was a little sticker on the Zen saying: FOR SONY NEX-7 ONLY...but it was sold and described as DJI Zenmuse Z15N for Sony Nex5/Nex7....but what the heck.

I still wonder how the Zen is supposed to know where the horizont is 100% level...can either be a sensor (but then it should always be level, regardless if balanced or not), or it depends on a 100 % perfect balance, which is not possible straight from the factory. Even using an aftermarket cam battery with a litte different weight would be enough to disturb the balance....very strange, but maybe Danny knows a bit more about it....

Anyway...glad you could fix it.


Chris

 

[DennyR]

I think your next move to get the best results from the S800, should be changing the props for wooden 15x4 Xoar or similar and stiffening the arms. Plenty of good examples currently flying reliably now. Do make sure your declination is set correctly. And yes the horizon is affected by how well you do the calibration.

FWIW the first thing I do with a new Zen is change most of those stupid set screws for proper cap screws with washers.

 

[MombasaFlash]

... After some diggin I found this vid:

Thanks for that link Chris. It would not have occurred to me to check the Pan balance. I did and sure enough ... it was way off.

I notice that DJI is pretty strenuous in their objections to folks undoing screws 'n' stuff. Well this is what had to be done in order to make this particular unit serviceable.

1. The camera frame was too high making the Tilt axis top-heavy once the camera was installed.
2. The camera fixing plate was too far back making it rear heavy.
3. The 'elbow' arms holding the Roll/Tilt assy were off-centre and allowed the camera tray to roll clockwise with the IMU down every time when not powered up.
4. The Roll/Tilt assy was off-centre on the Roll motor output shaft - this was the cause of the 1° off horizontal roll axis problem.
5. The same thing applied to the Pan Axis - it would not face forward by default, it was about 2° off-centre.
6. One of two grub screws securing the pan arm had a stripped thread and could not be tightened. This will have been done on the assembly line.
This left just one tiny grub screw to hold the Pan arm in place. If that one grub screw failed in the field the whole gimbal would instantly become unserviceable.
7. There was an omission to the 0.14 firmware that prevented Tx control of the Roll Axis in Mode H.Free.

All of the above issues have now been addressed and rectified and I am quietly confident that the gimbal can now be used, although flight testing will be required to confirm this. But at least it balances in every direction and the Roll axis comes to rest at 0.0°

... FWIW the first thing I do with a new Zen is change most of those stupid set screws for proper cap screws with washers.

+1

 

[BorisS]

Thanks for that link Chris. It would not have occurred to me to check the Pan balance. I did and sure enough ... it was way off.

I notice that DJI is pretty strenuous in their objections to folks undoing screws 'n' stuff. Well this is what had to be done in order to make this particular unit serviceable.

1. The camera frame was too high making the Tilt axis top-heavy once the camera was installed.
2. The camera fixing plate was too far back making it rear heavy.
3. The 'elbow' arms holding the Roll/Tilt assy were off-centre and allowed the camera tray to roll clockwise with the IMU down every time when not powered up.
4. The Roll/Tilt assy was off-centre on the Roll motor output shaft - this was the cause of the 1° off horizontal roll axis problem.
5. The same thing applied to the Pan Axis - it would not face forward by default, it was about 2° off-centre.
6. One of two grub screws securing the pan arm had a stripped thread and could not be tightened. This will have been done on the assembly line.
This left just one tiny grub screw to hold the Pan arm in place. If that one grub screw failed in the field the whole gimbal would instantly become unserviceable.
7. There was an omission to the 0.14 firmware that prevented Tx control of the Roll Axis in Mode H.Free.

All of the above issues have now been addressed and rectified and I am quietly confident that the gimbal can now be used, although flight testing will be required to confirm this. But at least it balances in every direction and the Roll axis comes to rest at 0.0°





+1

Yeah thats certainly not cool to get it in that state !!! I had one of the first gh2 versions so i guess back than it was still assembled with more concentration on who it balances out.

 

[MombasaFlash]

This S800/Z15 rig is all due to be taken overseas and it has been getting uncomfortably close to the departure date and still non-operational with the troublesome Z15.

But, I am happy to say that DJI China (yes, DJI China - not an agent) has directly responded to the issues with that Zenmuse and the matter has been all but satisfactorily resolved.

So credit where it is due and thank you to the good folks at DJI Head Office.

A word of thanks also to Matjaz at Kopterworx as the initial go-between and for his ever helpful manner.

 

[BorisS]

This S800/Z15 rig is all due to be taken overseas and it has been getting uncomfortably close to the departure date and still non-operational with the troublesome Z15.

But, I am happy to say that DJI China (yes, DJI China - not an agent) has directly responded to the issues with that Zenmuse and the matter has been all but satisfactorily resolved.

So credit where it is due and thank you to the good folks at DJI Head Office.

A word of thanks also to Matjaz at Kopterworx as the initial go-between and for his ever helpful manner.

Glad to hear that it was taken care of !

Boris