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Old Yesterday, 06:20 AM
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Originally Posted by mpjf01 View Post
Copter sets home when armed, plane sets home on GPS lock.
Thanks for the answers guys. I'm loving the complexity, Mavlink (especially) & configurability of APM . Up to now just experimenting with the modules with 3DR links connected to a laptop for ground station until my new 450 frame, ESCs & motors arrive. I've also ordered Boscam 5.8Ghz TX/RX video links with clover leaf antennas, Topcam HD camera, Mavlink OSD & APM power module & 7"LCD with CF hood & TX mount.
Looking forward to some good FPV that the "Fun Police" can't touch
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Old Yesterday, 02:28 PM
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Joined Apr 2014
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I did all the cable ties and shortened the power leads. Still spirals.
Notice that it does NOT YAW during the circle in loiter mode.

Loiter spriral (0 min 59 sec)

Did a compass cal again. Then compassmot setup with results at 2% of mag field.
2% should be good enough for stable loiter. Maybe this APM is defective.



Quote:
Originally Posted by TheQuestor View Post
Your voltage is a little low and your vibrations are a little high but nothing that should cause that issue.

Circling also know as Toilet bowl is almost always cause by EMF

http://www.rcgroups.com/forums/showp...postcount=1068
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Old Yesterday, 05:26 PM
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Quote:
Originally Posted by marx68 View Post
I did all the cable ties and shortened the power leads. Still spirals.
Notice that it does NOT YAW during the circle in loiter mode.

http://youtu.be/QhR7FkXFAyY
Did a compass cal again. Then compassmot setup with results at 2% of mag field.
2% should be good enough for stable loiter. Maybe this APM is defective.
It definitely looks like Toilet Bowl.

The shadow of it on the ground is drawing a circle.

No one said anything about yaw during the circling.

In my video that Questor linked to, I point out that;

It yaws at the instant it leaves the ground, not later and it is caused by me deliberately looping the Lipo leads near the compass

http://www.rcgroups.com/forums/showp...postcount=1068

Magnetic interference causes yaw on take off (1 min 27 sec)


Is your GPS on a stick ?

If it is and it is rotated slightly after compass calibration then that is guaranteed to cause this. The ease with which compass on a stick can be accidentally rotated is why I avoid compass on a stick and instead FIX the magnetic interference.

If you have strong varying magnetic fields causing magnetic interference, most likely caused by badly laid out wiring between Lipo and ESCs then that is guaranteed to cause this.

This LARGE Octa flies fine, no toilet bowl in loiter and does NOT require GPS on a stick because the Lipo to ESC wiring is planned and executed to not cause magnetic interference.



Here is the same Octa using the internal compass of the Fixhawk, no compass on a stick, what you see up on spacers is just a GPS, no MAG. Works just fine, Loiter is perfect.



Pay attention to Lipo to ESC wiring, either twist together or lay side by side and cable tie Black and Red leads between lipo and ESCs - INCLUDING the short eun from Lipo to Lipo connector, use a couple of cable ties to make sure they stay next to each other.

The reason for twisting them or laying next to each other si so their Magnetic Fields CANCEL each other.

Further - you need some physical separation - DISTANCE - between the Lipo to ESC wiring and the magnetometer, which is why the flight controller on the Octa is mounted on a raised platform which also helps to reduce vibrations from reaching the accelerometer, the AV Dome.



On an RCtimer Spider, the cable ties are NOT to make it look nice, they are to keep Red and Black Lipo to ESC wires together so that their magnetic fields cancel each other



Distance separating Lipo to ESC wiring from Magnetometer next to GPS on the NEO-6M GPS + MAG up on top of the nylon spacers.



Avoiding Magnetic Interference to the Compass by very carefully planned and executed Lipo to ESC wiring is extremely important, ignore it at your peril.
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Old Yesterday, 06:05 PM
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Joined Apr 2014
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I've done the cable ties, twisted and made sure +/- are zipped together.
Lines are near as short as I can get them.
Yes, the GPS/compass is on a stick. Never had a problem before with it on the previous builds. But, hell why not. I'll move it and lock it tight to the frame like yours and give that a try. I do know that if the mast is not rock solid then it won't stay stable in GPS modes. I glue the mast in place to prevent this. I guess this build doesn't like it.

Oh yeah, it circles. Worthless for loiter and RTL. I thought that since it pointed the same direction it wasn't compass interference. The mag interference is only 2%!






Quote:
Originally Posted by jabram View Post
It definitely looks like Toilet Bowl.

The shadow of it on the ground is drawing a circle.

No one said anything about yaw during the circling.

In my video that Questor linked to, I point out that;

It yaws at the instant it leaves the ground, not later and it is caused by me deliberately looping the Lipo leads near the compass

http://www.rcgroups.com/forums/showp...postcount=1068

http://www.youtube.com/watch?v=OPrP4...layer_embedded

Is your GPS on a stick ?

If it is and it is rotated slightly after compass calibration then that is guaranteed to cause this. The ease with which compass on a stick can be accidentally rotated is why I avoid compass on a stick and instead FIX the magnetic interference.

If you have strong varying magnetic fields causing magnetic interference, most likely caused by badly laid out wiring between Lipo and ESCs then that is guaranteed to cause this.

This LARGE Octa flies fine, no toilet bowl in loiter and does NOT require GPS on a stick because the Lipo to ESC wiring is planned and executed to not cause magnetic interference.



Here is the same Octa using the internal compass of the Fixhawk, no compass on a stick, what you see up on spacers is just a GPS, no MAG. Works just fine, Loiter is perfect.



Pay attention to Lipo to ESC wiring, either twist together or lay side by side and cable tie Black and Red leads between lipo and ESCs - INCLUDING the short eun from Lipo to Lipo connector, use a couple of cable ties to make sure they stay next to each other.

The reason for twisting them or laying next to each other si so their Magnetic Fields CANCEL each other.

Further - you need some physical separation - DISTANCE - between the Lipo to ESC wiring and the magnetometer, which is why the flight controller on the Octa is mounted on a raised platform which also helps to reduce vibrations from reaching the accelerometer, the AV Dome.



On an RCtimer Spider, the cable ties are NOT to make it look nice, they are to keep Red and Black Lipo to ESC wires together so that their magnetic fields cancel each other



Distance separating Lipo to ESC wiring from Magnetometer next to GPS on the NEO-6M GPS + MAG up on top of the nylon spacers.



Avoiding Magnetic Interference to the Compass by very carefully planned and executed Lipo to ESC wiring is extremely important, ignore it at your peril.
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Old Yesterday, 09:20 PM
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Quote:
Originally Posted by marx68 View Post
...Yes, the GPS/compass is on a stick. Never had a problem before with it on the previous builds.....
This could be caused IF the compass on the stick has been accidentally turned away from the exact position it was in when the compass was calibrated.
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