I've recently tried the Super-X on X8 built to carry a Blackmagic 4k. The frame is purpose built to carry Red Epics, an even heavier camera. It has not gone well, so I would appreciate any advice. The AUW is 20 lbs, Freefly 40 am escs and PDB, Tiger 4012-480kv motors, 16 inch APC props. The problem is that when I get the gains set so the gross movements in flight are best (about 105) a distinct vibration is transferred to the camera and the brushless gimbal doesn't like it. If I drop the gains on the Super-X and lose most of the vibration to the camera, the flight characteristics are terrible. I could sure have fun flying the Super-X around and all of the functions work great, but I haven't been able to make it work for a big camera. Any suggestions?
XAircraft SuperX on heavy lifter
- Thread starter octocine
- Start date
RyanMcCrae
Member
I have had the same issues, Kloner did to. He's managed to get rid of them. It comes down to having perfectly level motors. Check your logs to see what the motor outputs are. That will probably show that there off by a decent amount. I managed to get mine useable and I'm really enjoying Super X. But i need to change to a frame with square arms to really get it dialled in. Im running coaxial so its really tricky to get both motors perfectly level on my sky jib.
Thanks Ryan. My usual strategy for getting the motors level is to first level the entire frame on a table with shims under the wheels until it's perfect in all directions. Next I make sure the flight controller is level as well and when I mount the motors I put a level on the motor mount as well, so everything should be level. I don't have any yaw issues which has happened in the past when I had something out of level. I'll double check it though - thanks. Anyone have any other tips for leveling?
Paul - anything in particular I should look for in the flight logs. I don't have a baseline to know what's normal.
Paul - anything in particular I should look for in the flight logs. I don't have a baseline to know what's normal.
DucktileMedia
Drone Enthusiast
have you tried smaller or different props?
I haven't tried other props. I live at 6,000 feet and wasn't completely sure where I'd end up for AUW, but the 16s seemed about right on e-calc. My hunch is that there's just so much mass hanging on the frame that it looks and feels vulnerable to wobble - I know that doesn't sound very scientific. Of course, I tried every combination of o-rings on the vibration isolators without success. I know some people are using the wire vibration isolators, so I may try that later.
DucktileMedia
Drone Enthusiast
My personal experience which is mostly all coaxials, is that the alignment is not so critical that being a degree off changes much. but I know there are many that will disagree with that. I have had much more noticeable results from balancing props/motors and/or changing props. After all this is the source of 99% of the vibration. Logically it doesnt make sense that an arm being off would induce vibration. It would perhaps cause the controller to have to over compensate and be less efficient. I just don't buy into the thought that if you spend hours squaring your arms from visually square that you will all of the sudden have this amazing change. but I would love it if you proved me wrong. It also helps to understand that a low frequency oscillation is a lot different than the high frequency vibes we see when props arent balanced. You dont tend to see high freq vibes when flying where you will see them as jello or shake in your footage.
kloner
Aerial DP
the gains look way too high. to explain the system, the gain you see on the gui is the basic gains,,, the knob is the atti gain..... there is no way to see the atti gain except in your logs.... that should be 60-100 ish.... when the basic gain is too high and you crank up the atti gain dial, it'll shake like your describing. try .9 on all your manual gains, go back out and give it a lift then quickly increase the atti gain till she levels out.......
upload your log here
http://www.xaircraft.com/black-box/
and post us a link back to this post, lets see what you got....
like this http://log.xaircraft.com/#2014_03_24_063117.250_24.2.01.51
upload your log here
http://www.xaircraft.com/black-box/
and post us a link back to this post, lets see what you got....
like this http://log.xaircraft.com/#2014_03_24_063117.250_24.2.01.51
Thanks, that clarifies things for me. From reading the manual, I assumed the the gain on the knob was a sub trim for the main gain, but it sounds like it's actually a separate gain. I use a DX8 transmitter and a single operator system so I planned to use the dial (aux 3) for camera tilt. I used a three position switch for the second gain (guess I'll think of it as "attitude gain" now) and tried various offsets, but don't think I ever got as high as 60-100. I think I maxed out at 50, but by then I might have had the primary gain too high.
I kind of gave up on this setup for the moment and left for a ten day trip with my old setup. I'll upload the flight logs when I get back. Thanks! Very anxious to try it at .9 with some higher atti gains.
kloner
Aerial DP
are the freefly esc's simonK?
if this won't tune, the logs will help diagnose, but i might suspect the 490kv and 16" prop might be really tall on 8 motors.... just not sure what loss you get and if that fits the equation
also make sure to get up out of ground affect,,, 4-5' usually does it, but more turbulent coax might need even higher to clear it in a hover at these kinds of thrust levels...
if this won't tune, the logs will help diagnose, but i might suspect the 490kv and 16" prop might be really tall on 8 motors.... just not sure what loss you get and if that fits the equation
also make sure to get up out of ground affect,,, 4-5' usually does it, but more turbulent coax might need even higher to clear it in a hover at these kinds of thrust levels...
Beauregard
Member
So is the knob is controlling the amount of atti applied.. ie. Creating a setting that lies between manual and atti mode? (A percentage of atti mode?)
Beauregard
Member
Ok... Thanks.. So to help clarify.. How if any do the basic gains affect the manual mode?
kloner
Aerial DP
basic gains are the manual modes gains.... the atti mode adds self leveling, that's the knob..... a low gain is loose or sloppy, hard to control, a high gain will oscilate or hunt,,,
it is a combination of the two gains like any other flight controller that makes up the complete flight charecteristic..... in open source that opens up into hundreds of settings, this is the EZ button method
it is a combination of the two gains like any other flight controller that makes up the complete flight charecteristic..... in open source that opens up into hundreds of settings, this is the EZ button method
I think I've got the flight log loaded here: http://log.xaircraft.cn/#2014_04_06_131547.570_68.1.04.39
I've since tried to fly this as a quad, but I had no control at all when it became airborne. Next attempt was with main gain at .9 and atti gain at 80% and it turned over on takeoff. I seem to be going backwards. If anyone has any suggestions from the blackbox, I'd sure appreciate any advice.
I've since tried to fly this as a quad, but I had no control at all when it became airborne. Next attempt was with main gain at .9 and atti gain at 80% and it turned over on takeoff. I seem to be going backwards. If anyone has any suggestions from the blackbox, I'd sure appreciate any advice.
Thanks. It seems like the flight that it kept on the board was not the most recent one, so I think it was an octo setup. The last couple of flights were with a quad setup, but they were very short as it kept tipping over. Do short flights not write to the flight log? Perhaps my motors were not level, but I keep a close eye on them with a level. I'm running 16 inch props, 4012, 480kv motors, 50 amp Freefly ESCs. AUW is about 20 lbs. Neither motors nor ESCs feel hot after flight.
Beauregard
Member
I would check the gain setting in the black box.. I found that with my Futaba when I was thinking I was turning up the gain I was actually turning it down as the channels are backwards for Futaba.. (this is the dial gain not main gain).. Also make sure your not in manual mode.. Mine flipped over in manual mode at takeoff once just after a successful flight in manual mode.. Seems the controller couldn't handle the turbulence of ground effect and started a crazy pendulum effect and eventually flipped.. And of course because you can't manually turn off the motors continued to churn up the snow underneath it 