Hoverfly Hoverfly GPS

[DucktileMedia]

I finally had a chance to try out the gps board. Does anyone know how to tighten up the radius? I calibrated twice, the compass is very accurate and all calibrations are showing a check in their box. I was flying on a dead calm day in the middle of a wide open field. I am getting about a 30' circle. This was the same thing my wookong did before I plugged in all the perfect numbers but since Hoverfly has no settings, i dont really know what to do to fix it. The return to home I will say is buttery smooth and does not freak you out at all like the DJI does. Its just a switch position, you hit it and it starts to float home very gently with no jerky motions. I absolutely love this as it is probably the main reason I wanted the GPS other than to do 360 pans. Apparently the magnetometer is built into gps board so it is more susceptible to RFI than if it were floating like the gps rx. maybe it was the solar flares.

 

[JZSlenker]

Do you have any ferrous material near your gps/HFP boards? This could be fasteners, brackets etc. do you have any battery wires near your boards? (If you do, either move them or get the positive and negatives parallel and touching one another - twisted is even better). Remove or move any source of magnetic field. I switched to aluminum fasteners and saw a drastic increase in PH accuracy.

 

[Bowley]

Perhaps this systems suffers a little by having the GPS sensor on the board, like the APM2 which is also a little slack in PH, rather than the DJI method.

 

[DucktileMedia]

The gps sensor is not on the board, the magnetometer is on the board. And yes, there are 2 stainless bolts that I use to hold the gps rx to the arm. I wondered if that would do anything.

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[Bowley]

Ahh, I see now, thats good to know, just having a look at some spec, nothing stated about tolerances that I could see. 30ft does seem a lot. Only thing I can think of really is EMI from the 6 motor wires.
BTW, Have you tried the 'same path home' RTH function, that sounds handy.

 

[yeehaanow]

I wasn't aware that the magnetometer was on the board? I thought it was in the GPS rx?

I tried mine the other day for the 1st time and got about the same result. It wanted to wander around a bit in gps hold. My gps is on a carbon mast about 8-10" above the frame and behind the center plate.
There was some wind though.
I really only wanted the RTH and the OSD gps info, which is awesome to see. RTH seems to work. Only tried it once and did not let it stop itself. (if it does?)
I was wondering about the calibration, which says to point it north. Is that magnetic north, or true north? I'm guessing mag north, not that there's a big difference.

 

[DucktileMedia]

6 motor wires? You mean 24 motor wires. The RTH is absolutely a dream. After being scared to even try it out on the DJI I was thrilled to see how well this works. Once my radius gets tightened up a bit it will be even better. Really impressed at how smooth the Hoverfly is all around. Never a glitch, twitch, jump or dive. It makes me want to fly more rather than be happy to have it on the ground.

 

[Kari]

6 motor wires? You mean 24 motor wires. The RTH is absolutely a dream. After being scared to even try it out on the DJI I was thrilled to see how well this works. Once my radius gets tightened up a bit it will be even better. Really impressed at how smooth the Hoverfly is all around. Never a glitch, twitch, jump or dive. It makes me want to fly more rather than be happy to have it on the ground.

This HF is really beginning to sound tempting. I think it will be my next system to try out. Does HFgps work like "dynamic ph" so you can fly it on all the time or is it just ph which you switch on when you need to?

 

[Bowley]

I meant the 6 in that particular boom that your sensor is mounted on.
I have a HFP supposedly in transit. hope it gets here before xmas!!

 

[DucktileMedia]

Kari, the PH is dynamic. It says it takes 1.5 seconds for it to kick in which is kinda weird. but yes, if you move the sticks it slews about and locks to the new position as it should.

Yeehaw, on the RTH, I actually didnt think to let it stop completely. I was thrilled to see her come home in the right direction and slow down about where I started. Thats really all I need. it is useful for a fast flyby shot where I can now fly a little past my comfort zone LOS and rely on the RTH to bring her back to where I can regain control. Unlike DJI though, it is not a stressful panic flipping the switch on/off!

 

[yeehaanow]

Does it always maintain the same (current) orientation? Mine did but I wasn't very far from home.
The DJI turning and heading for home was always a little disconcerting, especially how abruptly is happened. This feels smoother.

However, since installing the GPS, I have noticed a slight drift in the yaw sometimes, particularly after takeoff. Not sure if it's a weight vs gains issue, as I added a case for the HF and the bracket for the gps.

Also, the OSD contrast adjustment is a bit weird because it's darkening the picture to brighten the text. It's not that easy to read and still have good shadow detail come through.

 

[DucktileMedia]

yes, orientation is the same. everything about it is smooth. I didnt have any weird yaw issues. The only thing keeping this from being perfect is the PH radius. I'll try raising up the gps rx and see what that does first. I doubt that's it though. Probably more to do with motor/battery wires surrounding the thing. It would also be nice if it acquired satellites quicker. My DJI only took 30 seconds, this took 2-3 minutes!

 

[Webheadfred]

I have my GPS antenna about 8" above the entire frame on an aluminum mast. I've replaces all the fasteners with aluminum as much as possible. My Y6 does a good job of holding within about 5 feet or so. Before, when I used stainless steel fasteners and I had torrids on the signal wires to the ESC's, I got what you describe. About a 30' radius.

 

[DucktileMedia]

Well, I dont have torrids but I do have a lot of wires dangling around the heli. Hoverfly mentioned an optional external magnetometer coming out soon. I'm thinking this may solve my problems.

 

[tahoelight]

I have not had success with my GPS. I even sent it in to HF to be inspected. They said it worked fine, but it won;t work on my X8, Y6 or my new Octo. George told me to replace all fasteners with aluminum to fix the problem. I just have not been able to find a good source for aluminum hex head in the 40mm length. If anyone is in the Tahoe (Reno) area that has a functional HF GPS, it would be interesting to install it on your multi to test.

 

[Webheadfred]

Tahoe.... It won't help you locally but I got my fasteners from here...

http://www.fastener-express.com/socket-head-cap-screws-silver-anodized-aluminum.aspx

They were reasonable and delivered fast.

 

[JZSlenker]

Yup if you want good GPS performance, you need to get good mag data. No, ferrous material, no magnets (teroids), no emf from power cables.

 

[tahoelight]

OK. I am going to try to get rid of my steel hardware. I can probably get away with some Aluminum 4-40 1-1/2" socket cap screws, but just barley on the main plate side. I would like to try to install some insert nuts rather than using regular nuts, so I can save time with dis-assembly. Has anyone used them on carbon fiber or G10? WIll I have to epoxy each one in? I was thinking about these http://www.mcmaster.com/#catalog/118/3214/=jodalg but they are not aluminum. I live in a dry climate so corrosion should not be a huge issue, but should I be concerned with aluminum and steel hardware? Will it defeat the purpose of going aluminum if I have zinc plated steel on the bottom side of the plate?

 

[DucktileMedia]

I dont know much about this but find it hard to believe the stainless fasteners that hold the frame together should be interfering with my position accuracy. I guess DJI having the compass built into the gps rx was a good idea. We'll see what evolves in the next few months with Hoverfly's gps technologies. I'm faithful they will make it as good if not better than DJI's.

 

[tahoelight]

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.