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Aug 04, 2013, 11:15 AM
Flying Wood For Fun
irun4fundotca's Avatar
Quote:
Originally Posted by JNJO
Hahaha, ffs.
Just flew in fairly windy conditions. 8-10 m/s stable.
Just for fun, I landed with FBWA. Nose in the wind, full flaps.
All I had to do was adjust the glide slope with throttle, then the damn thing landed itself softer than I will ever be able to do manually.
I think it's time to try an auto-landing.
great job!
once you get it setup it works good
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Aug 04, 2013, 02:29 PM
Chris
Thread OP
Quote:
Originally Posted by GraKez
I have purchased the longer ones that clip on inside the receiver, and they came with tuned ground planes!! Almost a half wave dipole, so the 2 elements end on end are about 5cm, so that is how high it will stick up, the 2nd one will be hidden on the foam.



This is all experimental, I won't know until I try her out.

With standard antennas at both ends, I was able to get 2.4kms "Line of Site" as I tested it out (not flying) but camera at one end and drove down a straight road.

I am guessing LOS I might score 4km with the 1/2 wave dipoles on the plane and a 7di directional on the transmitter. At least with the APM's RTL failsafe, I will feel confident about testing the limits.

I don't think 2.4ghz can penetrate much. What is your experience with your FrSky???

Graham
Oh tuned? That's another story nice...

I got 2kms on stock frsky gear. At 1.8-2kms I had 2 failsafes but as you said, its all good with the APM on board!
Aug 04, 2013, 02:29 PM
Chris
Thread OP
Quote:
Originally Posted by JNJO
Hahaha, ffs.
Just flew in fairly windy conditions. 8-10 m/s stable.
Just for fun, I landed with FBWA. Nose in the wind, full flaps.
All I had to do was adjust the glide slope with throttle, then the damn thing landed itself softer than I will ever be able to do manually.
I think it's time to try an auto-landing.
Great!
Can't wait to see how that works out!
Aug 05, 2013, 07:27 AM
When a hobby gets a passion
OK. I have spend many hours setting up everything, testing, checking and re-checking and I think I am almost ready to get my first test flight.

There is just a few things I need to know about testing the system on the bench. I have setup up 5 flight modes to begin with: Manual, Stabilized, Auto, Circle and RETL.

I noticed in Manual and Stabilized, I can control the throttle, in Auto, circle and RETL I cannot.

That means, this is on the bench, no GPS lock. Is that supposed to be correct?
Aug 05, 2013, 07:32 AM
When a hobby gets a passion
My second question is about the flight attitude. I noticed on the bench, when I switch from manual to stabilized, the control surfaces move. I haven't done a manual flight with trimming yet, but it seems to me that if I trim the plane to fly level in manual mode and I then switch to stabilized, it will adjust itself to the attitude it had when I initialized the plane (before trimming). Is this assumption correct? Or is there a way to tell the APM what is the correct attitude for level flight?
Aug 05, 2013, 08:47 AM
Done Posting, Gone Flying
JNJO's Avatar
Quote:
Originally Posted by Pattaya01
...I noticed in Manual and Stabilized, I can control the throttle, in Auto, circle and RETL I cannot.

That means, this is on the bench, no GPS lock. Is that supposed to be correct?
Yes, that's correct. FBWB, Cruise, Guided and Loiter will behave the same, with regards to throttle.
But beware of using them on the ground. The motor will spin in most cases.
Aug 05, 2013, 08:56 AM
Registered Lurker
Nethole's Avatar
EZStar has been retired. The rudder issue became terminal during testing.

On to the Magpie.

Initial flights, I needed to replace the control leads with dubro ezlinks, so I could precisely get the zero(trim). I had never worried about it in the past.

Now I'm actually seeing 'waggling' in FBWA which would suggest the RLL2SRV_P is too high. I'm using the default value. It's suggested this is unusual. But I also know the magpie can 'turn on a dime' at speed, so the value may be too high for this vehicle. I ran out of batteries last night, I'll test the reduction soon.

The dihedral coupling adds to the complications, but my old planes are serving very well as suitable test platforms to learn how to properly 'tune' the plane APM.
--side note, anyone remember how to reduce the 'vertical stretch' of flight logs when you display the kml files in google earth? I'm sure the stretch was there to make it appealing visually over larger distances, but for now, it's unnerving. (or is this the 600 feet of 'ground' isn't being mapped properly in google earth)
Aug 05, 2013, 08:57 AM
Done Posting, Gone Flying
JNJO's Avatar
Quote:
Originally Posted by Pattaya01
...it will adjust itself to the attitude it had when I initialized the plane (before trimming). Is this assumption correct? Or is there a way to tell the APM what is the correct attitude for level flight?
Yes on both.
The first case uses ArduPlane level or Manual Level. The second uses Auto Trim.
Good luck with your flight tests
Aug 05, 2013, 10:55 AM
When a hobby gets a passion
Thanks for the quick and very re-assuring replies. Flight tests will be documented in a few days I hope.
Aug 05, 2013, 07:22 PM
Registered Lurker
Nethole's Avatar

Magpie with APM


RLL2SVR_P reduced by half to 0.2

Smooth as silk now in FBW mode and loiter.
Aug 09, 2013, 08:57 PM
When a hobby gets a passion
I made a detailed update on my APM here: https://www.rcgroups.com/forums/show...postcount=2948

After the maiden, I will also post my experiences with the APM-Raptor combination here.
Aug 10, 2013, 01:46 AM
Done Posting, Gone Flying
JNJO's Avatar
Quote:
Originally Posted by Pattaya01
I made a detailed update on my APM here:
Nice build. Looking forward to the videos.
A few things that you might want to consider:
-Are you powering your servos from the APM? I cant see a UBEC in there.
-The GPS location. Try to get it on top. Ideally above the wing to improve reception.
-The telemetry radio antenna might suffer from being on top. Test it first. If it works for you, leave it.
-Telemetry antenna again. Some have found that the antennas coming from RCT are more suited for 2.4GHz transmitters, and yours look like one.

Good luck on the maiden.
Aug 10, 2013, 05:38 AM
When a hobby gets a passion
Quote:
Originally Posted by JNJO
Nice build. Looking forward to the videos.
A few things that you might want to consider:
-Are you powering your servos from the APM? I cant see a UBEC in there.
-The GPS location. Try to get it on top. Ideally above the wing to improve reception.
-The telemetry radio antenna might suffer from being on top. Test it first. If it works for you, leave it.
-Telemetry antenna again. Some have found that the antennas coming from RCT are more suited for 2.4GHz transmitters, and yours look like one.

Good luck on the maiden.
Thanks for taking the time to have a look. Your considerations are correct, but I have thought about your points already before you mentioned them for a while:

- Yes, I am powering them from the APM. I have a super oversized ESC with BEC and I trust it will work fine. But I am still considering using a separate BEC.
- I put the GPS antenna there on purpose as I want to try and see how well it works in that position. The advantage of that position is that it is very well protected. The disadvantage might be less sensitivity. Although from my experience with GPS is that it should be OK. I will fly not on Auto for a while until I feel comfortable. If not, I will surely move it to another location
- The telemetry antenna is sticking through the foam that works as a cover. I have flown like that before with the AP31 and never had a problem
- Yes, you are right. And I have my doubts about the range as well. So I will give it a field try first. But I think I have to replace them.

Thanks again for your remarks. Very much appreciated.
Aug 10, 2013, 06:28 AM
Done Posting, Gone Flying
JNJO's Avatar
Quote:
Originally Posted by Pattaya01
- I put the GPS antenna there on purpose as I want to try and see how well it works in that position. The advantage of that position is that it is very well protected. The disadvantage might be less sensitivity. Although from my experience with GPS is that it should be OK. I will fly not on Auto for a while until I feel comfortable. If not, I will surely move it to another location

- Yes, you are right. And I have my doubts about the range as well. So I will give it a field try first. But I think I have to replace them.
Let us know how the GPS works. Having it protected is always a good idea.
About the telemetry; I'm going to build dipoles for mine, as I suffer from 2.4GHz antennas too.
I never noticed on the Tricopter, but with the plane I fly longer range, and lost telemetry at ~200 meters.
I'll let you know how it works.
Aug 10, 2013, 10:18 AM
Done Posting, Gone Flying
JNJO's Avatar

On 2.4G vs 433M monopole antennas


Went out today to get a benchmark before I built and installed a dipole for telemetry.

The Ground Module is connected via an USB-FTDI interface to eliminate noise from the USB-port. Seems to work.

It turned out that the 2.4G-antennas was more or less useless. This was of course expected, but that it was that bad, was a surprise.

Below are pics of the antennas I used, and graphed telemetry logs with noise and rssi from both radios together with distance from home.
Note that the 2.4 drops out totally more or less at take-off.
The two drop-outs on the 433, I believe are from the antenna orientation, pointing the air module null straight at the ground module.

On to build a pair of dipoles.


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