Hoverfly Finally gave the GPS board a try...

[Bartman]

krzysiek,

i don't think that that is supposed to be that way. it sounds like you have a roll/yaw mix in your radio as that is how an airplane might be set up, to yaw a bit when roll is started.

the external mag should keep the heading from wandering but i don't think roll and yaw should necessarily be related like that.

bart

 

[Krzysiek]

Guys,

Could you check that in your setup and osd, is the same way i.e is the heading dependent on roll?

Just power the platform and check the readings on yous osd and in the setup while you roll the platform by your hands.

Thanks in advance.

 

[Bartman]

krzysiek,

i think i misunderstood you. i thought you meant that when you pushed your stick to the side for a roll input you also saw a yaw command entered. are you saying that when you roll the actual helicopter the heading indication changes even though heading is constant? how much does it change by?

 

[Krzysiek]

So, I am doing test now and the results are as follow:

If I roll the platform 20 deg to left (port is down) the heading decrease 30 deg.
If I roll the platform 20 deg to right (starboard is down) the heading increase 30 deg.

If I pitch the platform 20 deg to the bow (bow is down) the heading decrease 3 deg.
If I pitch the platform 20 deg to the stern (bow is up) the heading increase 3 deg.

 

[Bartman]

Krzysiek

I emailed Al about your problem and asked that he respond to your post. Hopefully he'll get to it sometime today. The behavior you're seeing is normal for a mechanical compass in an airplane but I've never heard of anyone having this problem with an RC multi-rotor helicopter.

When you roll the helicopter 20 degrees left or right, if you hold the helicopter steady at 20 degrees of roll does the heading swing back to its original value once the roll motion is stabilized or does it remain 30 degrees off heading? What frame are you using?

Bart

 

[Krzysiek]

View attachment 11830

Thanks Bart for your email to Al.

If I remember the heading does not swing back to its original value. I can not check it now.

The frame is made by me. It is made of carbon rods (22mm), G10 material.

 

[Photronix]

So, I am doing test now and the results are as follow:

If I roll the platform 20 deg to left (port is down) the heading decrease 30 deg.
If I roll the platform 20 deg to right (starboard is down) the heading increase 30 deg.

If I pitch the platform 20 deg to the bow (bow is down) the heading decrease 3 deg.
If I pitch the platform 20 deg to the stern (bow is up) the heading increase 3 deg.

Where are you Measuring the decrease of 30 deg? On the OSD screen?

 

[Krzysiek]

The heading deviation I checked in the setup and in OSD (osd has better precision).

 

[Krzysiek]

I performed calibration of the external magnetometer very slow (3 turns for each axis) and now the MAG works as it should. I have not tried PH and RTH yet. If the weather is good I will do it tomorrow.