Hoverfly Hoverfly GPS

[S11D336B]

Since I worked with you, I'm pretty sure we figured out what caused the problems you were seeing. I think it's related to magnetic interference from your ESCs/wiring harness. The compass would look fine on the ground, but swing all over the place while flying. Which may be why you were seeing heading changes while flying in mag hold. Basically, the solution is either moving your power wires/escs/batteries at least 6" from the board or using an external magnetometer. External magnetometer support is coming soon.

Iris, are you using steel fasteners? I have the boom clamps you made and can't find an appropriate aluminum screw that will work.
I don't know what else can be messing with my GPS, but I have it on an aluminum post as high as it will go with the supplies wire. If I even have my GPS board attached to my HFP board, I get weird yaw input and can loose control. It also immediately wanders off course when I set it to PH. Like i said, I sent it in and George said it worked fine.

 

[JZSlenker]

Tahoe, keep in mind that the mag is not in the gps antenna. Raising your gps antenna is not the problem. You need to get rid of steel fasteners and move your power wires away from the GPS board.

 

[DucktileMedia]

So even the stainless bolts that hold 99% of the heli frames out there together are going to prevent the gps from working? I certainly dont mind buying aluminum bolts as they arent under that much of a load. But i somehow have a hard time believing this is the cause. I can understand the power wires interfering though. But that is not an easy problem to address on most compact frames. I look forward to the external mag.

Thanks for jumping in on this thread and helping George.

 

[Bison52]

Are all stainless alloys magnetic (I think thats the term I'm looking for)? I'm building a Rusty's frame and the fasteners with the frame weren't attracted to a moderately strong magnet I tried to pick them up with.

 

[DucktileMedia]

No, there is martensitic(magnetic) and austenetic(non-magnetic). Most fasteners I have had are 316 or 18-8 which arent magnetic.

 

[tahoelight]

Does Auto Level rely on the Mag in the GPS board if attached? Because I have issues turning on Auto Level with the GPS board attached. It yaws without input even if GPS functions are turned off.

I am looking forward to external mag. Will we be able to upgrade our boards? I am not sure how I would move my wiring harness further away. The wires are all sandwiched in the center plates. I don't want to mount my escs on the booms and if the wires hang too low, the gimbal catches on them.

 

[JZSlenker]

No, no mag for autolevel

 

[S11D336B]

That's not true strictly speaking. Mag hold engages when gps hold or autoleveling is enabled if the gps board is connected.
So it could explain tahoe's heading change.

No, no mag for autolevel

Sent from my DROID BIONIC using Tapatalk 2

 

[JZSlenker]

Oh, apologies for the incorrect info. Why is mag hold used for AL with the GPS board?

 

[Bartman]

Does Auto Level rely on the Mag in the GPS board if attached? Because I have issues turning on Auto Level with the GPS board attached. It yaws without input even if GPS functions are turned off.

I am looking forward to external mag. Will we be able to upgrade our boards? I am not sure how I would move my wiring harness further away. The wires are all sandwiched in the center plates. I don't want to mount my escs on the booms and if the wires hang too low, the gimbal catches on them.

Ed,

I also had heading deviations with the GPS board plugged in but not activated.

 

[DucktileMedia]

It's interesting to see how some have issues and some dont. Bart and I have relatively similar frames and configurations, yet I have never had any erratic behavior at all with my Hoverfly. When I plugged the GPS board in nothing changed. I guess these components are so sensitive it just doesnt matter what brand you have, there are going to be varying results depending on your configurations. Hopefully this future release of the external mag will solve all these problems.

 

[S11D336B]

I feel like it's a logical extension of autoleveling. Heading locked to a magnetic heading just like pitch and roll are locked to an angle from the horizon.

Of course if your compass is having issues, you won't have a good experience with your heading. But on the flip side if you are having mag hold issues you know to test/fix this before trying GPS hold/rth

Oh, apologies for the incorrect info. Why is mag hold used for AL with the GPS board?

Sent from my DROID BIONIC using Tapatalk 2

 

[DucktileMedia]

Maybe it is worth it to add a check box in the software that allows users to disable heading lock in AL mode in case they can't get their mag to work right. Just a thought.

 

[tahoelight]

The issue with the mag hold when GPS is turned off, but plugged in, help me narrow down the problem. I always removed the board after testing so I am not carrying the extra expense that won;t work for me anyway. Problem is, I have tried to install it on 4 or 5 builds without success, so it sits on the shelf. Granted non have aluminum hardware, so I ma trying to make the decision to go aluminum 4-40 screws (will have to carry a different tool) or go stainless meteric and get the right size but get ticketed on the weight. Either way, I think this should be in the documentation to keep an eye out for.

 

[Bison52]

Just so I'm clear here, if your screws are the stainless alloy that is non-magnetic, are they still a problem or can they be used safely without causing mag interference?

 

[DucktileMedia]

Im sorry guys, I just can't for the life of me believe that these bolts have anything to do with the issue. Show me a Heli without stainless or steel bolts. They wouldn't make a board that was so sensitive it couldn't have any metal on it. It most likely has to do with all the power wires running everywhere. If the steel bolts affected the performance it would probably be compensated for when you do the mag calibrations. But I don't really know.

 

[Bartman]

Im sorry guys, I just can't for the life of me believe that these bolts have anything to do with the issue. Show me a Heli without stainless or steel bolts. They wouldn't make a board that was so sensitive it couldn't have any metal on it. It most likely has to do with all the power wires running everywhere. If the steel bolts affected the performance it would probably be compensated for when you do the mag calibrations. But I don't really know.

structures surrounding compasses can affect the heading readings but the errors would be constant and not necessarily cause fluctuations. the affects of the power wires on the other hand would constantly be changing and making the heading errors fluctuate so i'd have to agree with yuri that the bolts probably aren't doing anything bad. stainless bolts don't hold magnetic charges so i doubt they'd be doing anything to affect the compass.

 

[Bowley]

Agree with you. Thats the point of doing the compass calibration, with all the intended equipment fitted and powered, the metallic environment is a constant however Current changes constantly through flight, and you cant do a compass calibration with motors under load. I use magnetometers on ROV's that remain constant sat on steel vessels. I think the planned mod is the way forward.

 

[Bartman]

if we could just figure out a way to do without the electric motors........hmmmmm

 

[DucktileMedia]

Aha! I just tested this and it works perfectly! If you dont turn the heli on, the position hold works incredibly well. It's been a few minutes and the heli is exactly where I put it last. Altitude hold is even perfect. Return to home is very good. Also much quieter than when I plug it in.