SynDrones X8 Heavy Lift Build

Cbergen

Member
With your A2, what's your vertical gain setting? Too low and it may drop and climb through maneuvering...

OT, good looking bird! :)
 


Cheshirecat

Member
Hi,

I´ve been reading your thread and saw that you have kind of a similar problem as me. I also have a big X8 flying the epic. In my case a 15kg machine with A2 and Herkules Okto XL III. When I hover in ATTI mode it holds height perfect, but as soon as I fly somewhere I loose height. As soon as I stop the copter gains the height it lost.

As I am flying the A2 (also tested with wookong) I wonder why we have the same issue. Maybe it´s the hercules? Did you solve the issue?

I will switch to the mikrokopter electronics too for redundancy and to hopefully solve this problem.

Greetings

I was running a higher blade pitch on the lower props which did help with this issue 15X5.5 upstairs 15X6 down below until i broke one of the 15X6 and haven't got to replacing it yet so all 15X5.5 ATM
 


atomkind

Member
I think you cannot increase the speed on the lower ones but reduce the speed of the higher ones wit DJI.

I´ve tried that without success. Seems like DJI does not work on bigger X8 setups. I will put in the mikrocopter electronics over the next weekend.

I am running 18x6.2 T-Props btw.

Greetings
 


atomkind

Member
I think it might be that DJI does not calculate the loss of thrust when you tilt or roll a heavy and large (120cm motor to motor) X8. I simply had no chance to get it fly a straight line without loosing altitude. The copter regains altitude as soon as you stop but in coming home for example this will ground your copter.

I´ve been trying various prop combos and mixer tables without success.

Maybe someone else has an idea.
 

Cbergen

Member
My understanding of the system tells me that it should be able to hold altitude better than what you're describing. I hope that when you change to another FC that you let us know if you run into the same issue.

As I get mine flying, I'll certainly keep this issue in mind!
 

Lanzar

Member
I would connect the 2 Hercules boards supply together. Since now 1 battery supplies 1 st board and the 2 supplies the 2 board and there could be difference in consumption on them. Cause off coax even more. JUST a taught :) Bottom board is using more power than the top. Check the status on batteries after flight. THey will not match probably.
p.s: and later on send me some beer :)
 

Vojec

Member
I think it might be that DJI does not calculate the loss of thrust when you tilt or roll a heavy and large (120cm motor to motor) X8. I simply had no chance to get it fly a straight line without loosing altitude. The copter regains altitude as soon as you stop but in coming home for example this will ground your copter.

I´ve been trying various prop combos and mixer tables without success.

Maybe someone else has an idea.

Have same issue. In the past have 8kg X8 bird with T-Motors MT2814-11 710KV and hold altitude perfect from 0-30km/h in no time. Now have 11,5kg and 9kg with lower KV 400KV and have constantly altitude drop. I think that is normal regarding lower KV low RPM. With HI RPM motors easily holds altitude and response of bird is more quicker with aggressive flight...

Also waiting if someone will resolve and reveal that altitude puzzle on heavy x8.
 

Lanzar

Member
Well with settings it could be close but not perfect. But with 400kv or close motors and heavy kopter 10kg + this is just how it is with DJI. Add some trottle and it will hold it :)
THis is where pilot skils come to light.
 

atomkind

Member
Nice to hear that from Kopterworx too as you are "the" X8 heavy lifters out there with your hammer and you probably have the most experience with big x8´s.

I am looking forward to testing the mikrokopter electronics to see if it helps. I think you could also program a custom mixer on your rc to add throttle to nick and roll moves just like in the past rc days.

According to the manual Mikrokopter has something called "tilt compensation". Let´s see. Parts coming in tomorrow, build over the weekend.

Greetings
 

Cbergen

Member
Finally finished my Quad 8, and a good day for testing...going to do some time testing and test how it holds altitude in FFF.

http://youtu.be/LbNdO07luM4





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Hey Guys,
Bit of an update on everything with this copter. We have been flying it non-stop without any issues since this build thread started. I am still having a small issue with AH but we have figured it out. It's an issue with air hitting the AH sensor and causing it to descend. We are having a small part 3D printed to enclose the AH sensor so it doesn't get any dirty air. This should fix the problem.

@Lanzer: our Herkules boards are wired together. Each board is getting power from both batteries. If we loose a battery during flight the other will still power all 8 motors.

We did a test awhile ago and flew the copter, at full flight weight, on only 4 motors. Here's a video:

Nice to know it will still fly if I loose a board. This was on the top motors only which is why the bottom motors start spinning as I throttle up. It's just the wind. It was pulling a LOT of amps and I wouldn't want to have it in the air more than a minute or so.

Here is our most recent show reel. We love this rig!

Let me know if you have any additional questions or would like to order one of these frames!

Josh
 

Lanzar

Member
I dont know what strees wais made to hercules. Since its rated 30 amps while you were pooling probably 50 or more for hoover. But nice test.
Btw we would never fly 430kv version on hercules , 330 is on edge while 430 spikes to hard.

About bateries:
Depends on what happenes and when it happens. If you loose 1 cell then safe landing is doable. If the voltage is low and that happens then its a matter of luck. And how good the bateries are. best would be 4x 6000 6s :)
 

Hi Josh,

Thanks for your infos on you heavy X8. I am curious. How happy are you with the MK 2.5 setup? I built a setup for testing it (FC 2.5, MK Powerboard XL COOL, all fully redundant, 16kg) but it´s flying characteristics were just terrible and completely useless, no matter how I set up the gains.

I even shipped the whole copter to Mikrokopter but they could not set it up properly either.

The copter had it´s own life. (If you flew (in manual mode) with around 8 m/s forward and let go the stick it did not only stop slowly but came back the opposite direction at around 6 m/s for a while before it stopped etc.)

I used different motors however (Tiger U7 420 on 17" and 18" props)

Meanwhile I trashed the MK electronics and set up the rig with good old Herkules and double A2. Happy now.

Greetings,

Robert
 

stevemaller

Heavy Lifter
There are a lot of people (including me) who fly a copter just like that with MK electronics and it works fine. But they are difficult to get set up and a little fidgety sometimes. I have hundreds of hours of time on mine.
 

Yes we've never had an issue like that. How are you flying with dual A2s? We've tested an A2 and it ended in a crash. Copter started spinning wildly out of control then stopped and started spinning the opposite direction then went into the ground.
 

Hi, thanks for your answers.!

Funny we never were able to fly the MK electronics with success.

First I was quite worried with the A2 as initial tests showed it had an error with loosing satellites in GPS mode after hard stops etc. and I preferred the Wookong M for a long time.

On the new rig we have double A2´s connected by a redundancy electronic that automatically switches to the backup FC in case of failure (gyro drifts etc.). Further it´s possible to switch to the backup flightcontroller manually (we´ve tested several times in Atti and GPS mode). The electronic board we use was developed by Rudi Schneeberger from Austria (viewcopter). In Austria this redundancy is needed for permission as well as some further electronics that cut the battery (we have to use at least two batteries in parallel) if one battery fails to prevent the dead or shorted battery from killing the good one.

I´d wish we would have been able to use the MK electronics as we like the redundancy concept very much but the MK was flying super terrible.

Greetings,

Robert
 


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