APM 2.8 Mission Planner setup - 2nd opinion wanted - RC Groups
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Nov 01, 2017, 10:24 PM
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APM 2.8 Mission Planner setup - 2nd opinion wanted


At my wits end getting this thing to fly,. Teetering on the edge of just selling the parts off it and leaving the hobby behind with the absolute battle every part has been. 4 months and too much money wasted, every single step of the way showing up huge issues for no apparent reason for the pay off of about 1 minute of total flight time and I forget how many crashes.

I've got this:
FS i6 Transmitter
FS-iA6B Receiver
S550 frame
APM 2.8 Flight Controller
Ublox 7M GPS
6x Hobby Power Simonk 30A ESCs with 5V/2A Linear BECs
6x Hobby Power 2212 KV-920 Motors
APM Power Module
4500mAh 3S battery
Extras - Storm32 Gimbal/camera, FPV Transmitter.

What I'm after is some confirmation that I have got this set up right. And all my issues are not just something overlooked. The reason being that taking off is virtually impossible, the frame tried to flip over every time and IF it gets up in the air it's very hard to keep under control. Pressing trims on the transmitter cause 3-4 seconds of no inputs being recognised, Autotrim causes the same issue.

Linked HERE is a gallery of the Mission Planner wizard as I've gone through it, whats set and whats not.
Linked HERE is a gallery of the ESC issues I had. More as a reference to how everything is put together and wired up for this post.

Thanks
Last edited by PenguinActually; Nov 01, 2017 at 10:46 PM.
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Nov 02, 2017, 05:15 AM
Registered User
I would try some different ESC's with BLheli_S firmware. i've read those Simon K's are not good for quadcopters.
Last edited by SLFLY; Nov 02, 2017 at 05:24 AM.
Nov 02, 2017, 11:10 AM
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ariaAQ's Avatar
With 3 dead esc's i'm sure you've made some mistakes. Common problem: too long motor mounting screws touching the motor winding
Nov 02, 2017, 11:56 AM
Registered User
If you can barely get off the ground, your tune is wrong. If it is really trying to flip, answer me this: will it flip if you give it more throttle?

I would say check your wiring motor order. I spent two weeks convincing myself it was right. It took me a piece of paper, pencil and the motor order written and placed on the copter, plus 2 minutes, to find that I had been fighting with my need to be right, not the crafts needs.

I would take the gimbal off to get it in the air. Less to worry about on troubleshooting.

Escs going up in smoke suggest wiring problems, or just bad.
Robert
Nov 02, 2017, 07:23 PM
FA3PR9WM79
Oldgazer's Avatar
Quote:
Originally Posted by SLFLY
I would try some different ESC's with BLheli_S firmware. i've read those Simon K's are not good for quadcopters.
An APM flight controller running ArucCopter 3.2.1 (The final version for APM) does not support BlHeli, so buying BlHeli ESCs is a waste of money.
Nov 02, 2017, 11:13 PM
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Madhampster's Avatar
How many inch are the props. They look to big for that kv of motor. That would explain why the esc burnt out.
I ran the same frame with 8 inch props. What is the pitch of the props.. Set it up without the camera and gimble off it first. When you are able to fly it add the camera back.
Last edited by Madhampster; Nov 02, 2017 at 11:21 PM.
Nov 03, 2017, 03:51 AM
Registered User
The ESC gallery is unrealated now, that issue has since been fixed due to more than likely winding screws into motors too far, paranoid that they'd vibrate out, it is linked only to show what the S550 looks like and how the parts are installed.
I have 7 brand new spare HP Simonk 30A ESCs now due to a checkout/shipping error so I'm sticking with them if I end up keeping this.

Everything spins up perfectly fine if I bump the throttle after arming I have CW/CCW and Motor 1,2,3,4,5,6 marked out on all the arms to streamline any checks on what way the motors are spinning.

Props are 10 inch. 1045/1045R

Very first liftoff it tried to roll over, turned out I reversed motor wires for 1 motor so it was spinning backwards. The loud vibration/buzz the prop made spinning backwards was a huge help in noticing and something I specifically have looked for any time since.

I have managed to get it off the ground a few times, but it's incredibly unstable when it about to lift off, it really tries to roll or pitch itself as the legs are leaving the ground, then it drops to a reasonably level hover with slight float that I can't trim.
You have to 100% commit to a somewhat aggressive take off to minimise it's skittishness compared to slowly edging the throttle up.

Then once you get to the point of take off it might fall over, it might pop up as you'd expect. It's hard to tell because visually, watching the labels on the motors, everything looks the same speed and none of the propellers sound noticeably louder or quieter than the rest.

I have run it without the gimbal for less weight, and moved the battery to the center underside to balance the center of gravity out.

I have not messed with PID settings in any way, shape or form. Trims have ended up with crashes regardless of trimming with the transmitter or the APM Autotrim. Trimming in any way causes a "lock up" where inputs just stay as they are for 3-4 seconds, then i either have a crash or everything starts responding again in the air.

Could the APM be defective? Assuming that they're still a some what popular choice.
Nov 03, 2017, 06:57 AM
FA3PR9WM79
Oldgazer's Avatar
After you arm the motors you need to get into the air "smartly". Sitting on the ground "nursing" the throttle causes "errors" in the PID loops to build to the point where the aircraft will "go crazy" shortly after take off. This is due to the fact the flight controller "thinks" the aircraft is flying when it isn't.

The trim issue still puzzles me, but the "drifting" is normal. Any aircraft no matter how meticulously it is built, calibrated and mechanically aligned will drift randomly in a hover. The only real way to stop this is by "flying" in Loiter.

We need to see the logs....
Nov 03, 2017, 05:57 PM
Registered User
Madhampster's Avatar
Never move the trims once you have it claibrated in mission planner. I set mine to gps hold when i am off the ground to maintain altitude and postion. I always punch the throttle to get it off the ground so it doest tip.
Nov 04, 2017, 06:01 AM
Registered User
Noted on takeoff. I've been trying to edge the lift up to test before take off to see if it was going to tip over or not.

Trim wise. If I could get rid of the CCW yaw I'd be a lot happier, haven't had the confidence to try loiter mode with it while trying to keep a close eye on everything. Might be worth trying auto trim, 10+ meters high incase everything locks up, at least it'll be able to float down a meter or 2 without crashing .

Log wise, I have a total of 73 saved from a "HEXAROTOR" folder off the APM, and 3-4 in a "SMALL" folder off the APM.

What sort of files would be useful to look at?
Nov 04, 2017, 07:37 AM
FA3PR9WM79
Oldgazer's Avatar
About a half dozen of the most recent .bin files from Program Files(x86)/Mission Planner/logs/HEXAROTOR/1, and the larger the file the better...

Put them in a .ZIP archive and post them here....
Nov 05, 2017, 01:59 AM
Registered User
No worries. I've included the recent logs over 10kb in size, average size is around 30-40kb with the 2 considerably larger files being included.

File "55" is presumed old as all the dates are the same according to the APM but being a lot larger than most I threw it in anyway.

Log Files - (Dropbox)

If Dropbox says to login to download, you can close their wee details box and download anyway.
Nov 05, 2017, 09:09 AM
FA3PR9WM79
Oldgazer's Avatar
I have looked at the logs.

Using the log browser isn't telling me much except some EKF issues, but Auto Analysis showed some errors.

55 show a brown out.
64 shows a battery fail safe.
65 shows a brown out and a battery fail safe.
66 shows a battery fail safe.
67 won't load, bad input file.
68 show GPS fail HDOP 99.99
73 shows throttle never above 20%

None of the logs had any GPS or Vibration data, and it could just be me, but the current and voltage data didn't look right in that decimal points were missing.

For example, looking at the point values of a voltage plot in the browser I see this: 5669, 1166.

The first number is the line number and the second is battery voltage which should be displayed like this: 11.66. Current is the same way. I get 4415, 1844.

I also noticed that when the aircraft appears to be airborne, throttle is at 57%.

Another puzzler is using pW (Power in Watts)= Voltage x Current, I get just over 200 watts. Divided by 6 I get 33 Watts per motor. That seems a little high, but this may be because you have not had the aircraft airborne long enough to make some battery monitor calibration flights.

Even so, we need to find out why the APM is browning out, so let's talk about what +5 volt loads you have connected to the APM besides the receiver and the GPS...
Nov 05, 2017, 11:21 PM
Registered User
Will the APM start logging if it's just being powered via a USB cable?

I had a look loading the logs via mission planner but I couldn't make heads or tails of what was going on.

All connections to the APM are:
- Power Module
- Output 1,2,3,4,5,6 to the ESCs, All have 5V 2A BECs that are Linear and shouldn't worry anything.
- Channel 1,2,3,4,5 from Receiver
- GPS, but not the external compass wires that plug into the side of the APM.
- Jumper to enable internal compass

Battery + and - run to the power module, and the balance port can be used to power the gimbal but I was expecting that to be causing the issue so I ended up having the gimbal on the frame just as a final weight, but using no power for some of the flights, not that it made a difference.

Interestingly I had a battery fail on my a few hours back. I noticed it sitting on my desk and it had puffed up about a quarter over it's normal size, all 3 cells visually puffed up a bit. I've since put it into an empty, old paint tin in case it fails completely. I wasn't too keen on putting a voltage reader on it in case that triggered anything. I had it sitting around 10-10.5V while the recent rainy weather was passing.

This had me thinking that there may be excessive droop under not too much load, but at one point I had it up and flying very aggressively the same way I could throw my small, lightweight, MJX Bugs 3 around and everything held up fine at the time.

Even with the gimbal and camera onboard but not powered on (gimbal braced) but again, trying to trim immediately afterwards caused what I guess now was a brown out.
Nov 06, 2017, 08:47 AM
FA3PR9WM79
Oldgazer's Avatar
Quote:
Originally Posted by PenguinActually
Will the APM start logging if it's just being powered via a USB cable? No.

I had a look loading the logs via mission planner but I couldn't make heads or tails of what was going on.

All connections to the APM are:
- Power Module
- Output 1,2,3,4,5,6 to the ESCs, All have 5V 2A BECs that are Linear and shouldn't worry anything.
- Channel 1,2,3,4,5 from Receiver
- GPS, but not the external compass wires that plug into the side of the APM. Use the External compass. You will get less interference from the power system. Calibrate the compass and then run Compass Motor Calibration
- Jumper to enable internal compass Remove the jumper...

Battery + and - run to the power module, and the balance port can be used to power the gimbal but I was expecting that to be causing the issue so I ended up having the gimbal on the frame just as a final weight, but using no power for some of the flights, not that it made a difference.

Interestingly I had a battery fail on my a few hours back. I noticed it sitting on my desk and it had puffed up about a quarter over it's normal size, all 3 cells visually puffed up a bit. I've since put it into an empty, old paint tin in case it fails completely. I wasn't too keen on putting a voltage reader on it in case that triggered anything. I had it sitting around 10-10.5V while the recent rainy weather was passing.

This had me thinking that there may be excessive droop under not too much load, but at one point I had it up and flying very aggressively the same way I could throw my small, lightweight, MJX Bugs 3 around and everything held up fine at the time.

Even with the gimbal and camera onboard but not powered on (gimbal braced) but again, trying to trim immediately afterwards caused what I guess now was a brown out.
Some answers are in RED .

The only thing I use the balance port for is a Battery Alarm . I put some sticky Velcro on the alarm and the back of the battery.

LiPos will "puff" when they are over discharged, or left sitting with a full charge. The "puff" is caused by the cells out gassing Oxygen. Over time this will reduce the battery capacity, and in extreme cases can cause the cells to rupture and catch fire. This is particularly dangerous because the fire is self sustaining. The battery chemistry uses Lithium which is a reactive metal similar to Cesium and Sodium. These elements are known for their propensity to produce a violent exothermic reaction with water. This results in a Class D (metal) fire which is very difficult to extinguish. If you know you are not going to use the batteries for any length of time, use your charger to discharge them and then give them a Storage Charge.

To power other "accessories" like retracts and gimbals I use separate BECs. The additional weight is negligible, and the voltage is constant regardless of main battery voltage.

I am still looking into this trim/brown out issue. I can say I have never seen it with an APM or a Pixhawk when using either radio trims or AutoTrim....

Getting a handle on using the logs will take a little time. You can find more info here: http://ardupilot.org/copter/docs/common-logs.html

Basically there are two ways to "look" at the flight data logs. Once they are downloaded you can either Review a log using the Log Browser, or you can us Auto Analysis to give you a "quick and dirty" summary. Auto Analysis is good for finding brown outs, imu mismatches, and so on. Using the Log browser allows you to plot various data sets like Current, battery voltage, total current used, vibrations, GPS Glitches, and so on..

The data I use most are Current, Total Current, Volts, VCC, RCIN, and RCOUT.

When load a log into the browser you will see a "tree" in the lower left pane. Clicking on a + box will open that branch, and ticking a box will plot that data set.

When you get a plot displayed, Right Clicking in the display window will bring up a menu. Clicking on Display Point Values will allow you to hover the mouse pointer over a point along the plot and display the line number and the value of that point. For example, if you plot CurTot and over at the end of the line, you will get the line number and the total current used during the flight...

Another important data set is Vibrations. By default, APM does not log vibrations because doing so can over tax logging and cause skipped lines, so for an APM I use vibration logging only during my initial flight testing or if I suspect vibrations may be impacting Loiter or other flight characteristics. You can change what is being logged by changing the Log_Bitmask parameter. To see a plot of vibrations, click on the drop down box in the center of the log browser window below the data plot pane and then click Vibrations. 3.3 Vibrations is used for AC3.3+...


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