Multirotor, multicopter and quadcopter discussion - The Drone thread

Kanifee said:
My rx is mounted in the center of the top plate, i dont think separation is as big of an issue with 5.8 and 2.4ghz equipment, now using 1.3ghz and 2.4 it becomes a real issue, the suggested minimum distance for that set up is like 30cm of separation.

So tuning pids, i hear increase d decrease p etc for osculations and the such but if the oscillation is just in the hover what value do you adjust the pids on, yaw pitch or roll? this is what i struggle to understand realy, what is it you are looking for to indicate what value to adjust the pid associated with it?
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As I understand it.......

P is the corrective force applied by the controller to make the quad match the input from the sticks. It will change how licked to the sticks the quad feels and how quickly it responds. Too high a value and it will overshoot then correct itself. These are the fast oscillations you get. Raise (or lower in your case) P until it is just starting to oscillate, then lower a few points more. Changing pitch or brand of props can affect this, as can frame vibrations.

I is the corrective force applied over time. If this is too low, the quad won't hold the angle you want and will gradually drift over time. So in acro mode, if you at the quad flying forward and the nose gradually rises back up to level, you need higher I. Raise until you get slow oscillations, then back off again.

D is the one I don't understand so clearly but it affects how aggressively the controller applies the above corrections. So a higher D will soften the feel of the stick inputs (Damping?)

Roll and pitch are very close on mini quads so should be the same, or as near as dammit. Yaw is slightly different in that the pid controller affects the quads ability to hold altitude while yawing and any potential overshoot. Too high P will make the quad rise when you yaw.

Roll/pitch and yaw rate exponentially drop the influence of the pid controller as you move the sticks to the end of their travel, effectively increasing response and rotation rate. RC rate is the same but is linear a opposed to exponential.

TPA lowers the pid's as you increase the throttle and is useful for tuning out wobbles on higher throttle that you will probably only notice in the video.
 
gandhi said:
As I understand it.......

P is the corrective force applied by the controller to make the quad match the input from the sticks. It will change how licked to the sticks the quad feels and how quickly it responds. Too high a value and it will overshoot then correct itself. These are the fast oscillations you get. Raise (or lower in your case) P until it is just starting to oscillate, then lower a few points more. Changing pitch or brand of props can affect this, as can frame vibrations.

I is the corrective force applied over time. If this is too low, the quad won't hold the angle you want and will gradually drift over time. So in acro mode, if you at the quad flying forward and the nose gradually rises back up to level, you need higher I. Raise until you get slow oscillations, then back off again.

D is the one I don't understand so clearly but it affects how aggressively the controller applies the above corrections. So a higher D will soften the feel of the stick inputs (Damping?)

Roll and pitch are very close on mini quads so should be the same, or as near as dammit. Yaw is slightly different in that the pid controller affects the quads ability to hold altitude while yawing and any potential overshoot. Too high P will make the quad rise when you yaw.

Roll/pitch and yaw rate exponentially drop the influence of the pid controller as you move the sticks to the end of their travel, effectively increasing response and rotation rate. RC rate is the same but is linear a opposed to exponential.

TPA lowers the pid's as you increase the throttle and is useful for tuning out wobbles on higher throttle that you will probably only notice in the video.
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Great post and thank you. I tried controller 3 and 5 both with similar results at stock but the pids are double yours so stands to reason.
It makes a bit more sense now, I will stick a old battery on and get her in the garden for the initial tune and then in to the field for the rest.

My AUW is..... 580g :o, should be ok though. looking out the window today it appears calm and dry so I should be able to test her out.

What effect does loop time play? I have heard that it can be limited by the quality of your esc? I only have afro esc at the moment but would love some 18a kiss to move to 6" props in the future.
 
Looptime is how often the fc runs a control loop, lower being faster. Theory is that the more calcs done a second, the better the control. The issue is that the fc only sends a command to the esc so many times a second so running a loop faster than that is a waste. This is where oneshot chores in as it increases the rate the fc can send command to the esc. Too be honest, at my level of skill I doubt I notice that much difference :)

Not sure but dependant on which chip is in those afro esc you could probably flash them with blheli 13 which would give you both oneshot and active braking.
 
Drift. The quad will drift in across now badly. I take it I have to adjust I for that. I have tried but maybe I need more I. It is like auto level mode calibrated on a wonky surface, it will just drift madly
 
Kanifee said:
Drift. The quad will drift in across now badly. I take it I have to adjust I for that. I have tried but maybe I need more I. It is like auto level mode calibrated on a wonky surface, it will just drift madly
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Little bit more I and poss slightly higher D, assuming you've got p high as you can.

Also, just a thought but excess vibrations can cause similar symptoms (drift, oscillations) have you checked new props fit balance and that your motor is ok after that prang?
 
Attempt 1 getting no lift off the ground. Motors spinning right way, throttle range seems ok, not exactly heavy I have no camera gear on there. Could there be an issue with props or prop slip? Its self tightening but at higher rpm could the props be slipping?

Battery fully charged
 
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DJMK4 said:
Attempt 1 getting no lift off the ground. Motors spinning right way, throttle range seems ok, not exactly heavy I have no camera gear on there. Could there be an issue with props or prop slip? Its self tightening but at higher rpm could the props be slipping?

Battery fully charged
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Are the props the right way round? high part needs to spin into the body of the quad.
 
Better

but something still a bit unstable, so I aborted

Im more nervous about taking this thing up than I did when I first took my DJI up when I first got it. Think its just becase its so small feels like its going to break in to pieces

Probably have a check over tonight and work on some teething issues then try again tomorrow, its a bit windy here now
 
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Storage charge on IMAX B6

What should I be storing my 4s 25-50c 4000mAh at??

edit - think I've found it - 3.7v a cell (so 14.8 or just above) - right?
 
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booyaka said:
Storage charge on IMAX B6

What should I be storing my 4s 25-50c 4000mAh at??

edit - think I've found it - 3.7v a cell (so 14.8 or just above) - right?
Click to expand...

If you use the storage mode on the B6 I'm pretty sure it defaults to 3.8v per cell. All my 3s stop at 11.4. It's a pain when I don't quite empty them enough and the charger has to discharge down to that as it will only do it at 1a.
 
I have had a great day, took the quad out this morning after spending an absoloute age tuning pids and setting rates to bury it in to the deck, my extended top plate was too thick for the bolts which couldn't get a tight enough grip and the whole quad exploded. Contents all over the floor, upright posts bent.... not a good start.

Took it all home and bent the uprights back in to place, fitted the old top deck and fastened everything down to realize my board camera wasn't there! So i watched all the footage back and went to the location.... found it! great news. So i take it all back home and fit it and low and behold it doesn't work :(

Ok i think, shake it off and don't worry, i can pick up a super had for £25. It isn't ideal but what are you going to do. I set up the quad with no fpv gear and take it for a flight. Holy cow it is a beast, the 5040's and the 4s mean it just glides with so much punch the field starts to feel small. I pull some great maneuvers, double barrel rolls, double flips, fast flips 4 feet from the ground as it has so much power it barely moves in height for the acro maneuvers and pulling them off at fast flight is a dream. If i do say so my self i had some amazing flying for me.

I get home and go to load the video from the mobious. But wait, what do i find...... black screen with audio! I had left the lens cap on :(

DJ take your bad luck back, i don't want it any where near me!
 
Yeah the B6 goes to 3.8v.

The weathers lied to me and its dry today when it said it would rain :(. I might charge up and see if I can slot in an early flight tomorrow, unless it rains :(.
 
Currently rebuilding my 250 after a few broken arms recently :-(. Printed a battery holder today to make things a bit neater.

Going to tidy some of the wiring trw and see if the weather is good for a fly later.
 
Bit of filming today over water... way to windy, batteries killed by cold, flytrex live fell off dangling by wire... and best noob mistake of day, checking GoPro was on while in flight, Taranis RSSI went critical then bombed out triggering failsafe and loss of control. I didn't put two and two together so watched it land itself on a busy pavement at beach unable to regain control. All I needed to do was step away DOH

With lack of footage just quickly stitched together and chucked on youtube for the SUP club.

http://www.flytrex.com/mission/hexacopter-dji-f550-flame-wheel-dan-bailey-TIpT0j8M/

 
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Kanifee said:
I have had a great day, took the quad out this morning after spending an absoloute age tuning pids and setting rates to bury it in to the deck, my extended top plate was too thick for the bolts which couldn't get a tight enough grip and the whole quad exploded. Contents all over the floor, upright posts bent.... not a good start.

Took it all home and bent the uprights back in to place, fitted the old top deck and fastened everything down to realize my board camera wasn't there! So i watched all the footage back and went to the location.... found it! great news. So i take it all back home and fit it and low and behold it doesn't work :(

Ok i think, shake it off and don't worry, i can pick up a super had for £25. It isn't ideal but what are you going to do. I set up the quad with no fpv gear and take it for a flight. Holy cow it is a beast, the 5040's and the 4s mean it just glides with so much punch the field starts to feel small. I pull some great maneuvers, double barrel rolls, double flips, fast flips 4 feet from the ground as it has so much power it barely moves in height for the acro maneuvers and pulling them off at fast flight is a dream. If i do say so my self i had some amazing flying for me.

I get home and go to load the video from the mobious. But wait, what do i find...... black screen with audio! I had left the lens cap on :(

DJ take your bad luck back, i don't want it any where near me!
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Sorry about that :(

Hope you get it all sorted and flying soon.


I just got mine in the air, feisty little buggers aint they, slowely getting hang of correction on stick movements, its very easy for a bit of wind to pick up and off it goes though. Although I would say it held up pretty well as higher up it is a tad windy today. Lost orientation a couple of times

Im guessing out of the box and on stock settings it acts like this though, and you need to tune it down to become more controllable and less sensitive?


But had around 4 minutes of actual fly time, didnt use the battery completely, had two crashes, one in to some tree's after i misjudged the direction it was going in to a next field, so I cut the throttle slightly, then cut it full, but before I did that I managed to flip the thing before it went in to the tree :p then second time was from around 20feet up, had to cut the throttle again, came down and broke a prop.

Im going to have to get used to not having GPS lock, I can fly in atti mode in normal cases fine, im good wth my DJI. But this is a little harder to control obviously.

I must say they are quite fun to fly though and the frame seemed to withstand some knocks ok.

Will have a look at that in a sec flukester
 
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gandhi said:
If you use the storage mode on the B6 I'm pretty sure it defaults to 3.8v per cell. All my 3s stop at 11.4. It's a pain when I don't quite empty them enough and the charger has to discharge down to that as it will only do it at 1a.
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hmm - yes just found that 2 hours discharge and it's only down to around 3.95 a cell. (15.7 on 4s)

That will do for now anyway - likely to be out and about this week probably with it all.
 
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