Coyotewing 60" Delta Wing

[Coyote]

Ok update time, been busy changing and trying things, all the pictures are of the mods unfinished, they only need taping up but they stick out more this way.

First up was the thumb grip mod, after seeing Thomas easy launch video and Martins results it had to be done. It was also handy doubling up as a landing skid because i wanted the nose lifted :



You can also see I`ve also dropped the Gopro chair into the fuse now, i found it was a bit too exposed for my liking so i sunk it in. This of course ment i could also lower the speed pod and reduce drag too :) With regards to the speed pod, thats changed too. I split it into three setions, the front is now permenantly attatched to Gopro chair offering even more strength, then i permenantly attached the 3rd piece to the hatch. Why ? Because i wanted a better way of securing my flight lipo in. To do this i cut the pod into three but keyed the center piece. Now it slides in and locks the lipo down without adding weight, thats why the other two pieces are now permenant :)





Now of course the lid would keep falling down when im trying to work on it, so i used one of the original magnets that kept the speed pod on and added a magnet to the permenant piece on the hatch. When its open the two magnets keep it up :)





I have also reworked most of the electronics now. I have moved the video to the left hand side of the wing, completely seperate from the power side. The vtx has swapped sides and been moved further out the wing. The GPS is even further still near the wing tip ready for the EZOSD and eventually replacement DOSD when funds allow. Ive also fitted the EZOSD current sensor too. Because im not using the DOSD it meant running servo wires from all channels of the Dragonlink to the hatch, the wire and crimps have been kindly provided by Paul ( pk-surfing ). This way, if i choose to run EZOSD or DOSD the wiring is there now so i can swap via a few plugs, no mods :)

I have also fitted a GY401B HH gyro, the second will be fitted in the next day or two, each gyro will for now control pitch and roll axis for a poor mans stabilization deveice, for it to control both access equally the gyro has to be placed at 45 degrees. In this case i want more roll control than pitch so i put mine at 30 dergees. The gain of the gyro can be adjusted in flight via my ch.6 pot.



The video equipment is now supplied completely seperate from the rest of the plane via a balance lead socket located near the lipo :



The CG has now been moved forwar to 24cm, and a gopro dummyload added. Hopefully all will be trimmed by tomorrow and the second gyro fitted by the weekend for some action with Paul :)



Oh yeah, i moved the winglets back too a bit, look miles better and fitted a camera bracket to the gopro chair for adjustability so the Gopro can point down and the camera point straight too :)

[mark1975]

Looks good ian  good.luck at the weekend ..

[Coyote]

Today i decided to start my conversion from linear video transmission to circular. Having a circular patch already mean the first logical step was the vtx antenna. At the power restrictions we have in place in the UK using circular seems the best way forward, banked turns etc wont be a problem any more :)

The antenna i chose to make was the cloverleaf design. I followed Alex`s tutorial and after mk 1 didnt look right i realised that I`d made a 2mm mistake and started again. The whole build only took 20 mins from start to finish, it was fiddly, the soldering was the hard bit though, had a few goes at that one lol

I used 1.5mm copper wire, normally soft once i realised how short the elements were i figured it would be fine. Bent the wavelengths in, the angles, soldered the first element on, then positioned the second one so all were at 60 degress and 120 degree spacing and it started to look like it should :)



Not pretty but accurate, i then re-did the soldering again !! because it was a mess lol, then tested it for vtx in the plane



Added glue to stop shorting the two elements out, and once the glue had set the antenna was much much stronger.

In this pic there is the GPS sensor i relocated behind it ( Forgot to photograph it previouisly ) to give you some sort of scale, its not half as big as you would think but much stronger than you would.



Hoping to test it tomorrow after todays flying was cancelled because I`d forgot Donna`s birthday :)

[Badlands]

Very interesting Ian - ill be checking back here to see your results.

:-)

[Coyote]

Ok, another few days another few changes. I painted up the antenna for looks only ( protection very little ) :)

Then i moved my attention to the winglets. After a bit of chatting on shout various possibilities were thrown into the mix. The reason for these ideas was two reasons.

1) On landings, even great landings, the winglets, held on with hot glue would come away. After a few times of this happening i found it annoying.

2) Both myself and Badland have had accidents with the winglets catching on objects.

My first mod was to put the winglets further back, this would cure the hooking ( daft flying ) problem, but again on landings they would come away. I 5 min epoxied one of my winglets on once, the result ? The winglet didnt come off, but thats when it hooked and span the wing destroying my gopro, so i was a bit put off using it again ( epoxy )

So one idea put forward was mounting the winglets on top of the wing. They could be placed anywhere from the middle to the outer edge of the wing. They would still be functional in performance, have no contact with the ground and lateral forces so wouldn`t come away on a landing.

The other option was cut the bottom off the winglet so its not in contact and leave them on the end of the tips. This method i choose to use after experimenting with the other



And so, the wing now looks like this :



I also made up a UHF Turnstile antenna for the Dragonlink. At first, it appeared to be smaller than the original antenna. But after completion, it was in fact bigger. Positioning the antenna in a horizontal plane meant the elements would hang over the end of the wing in nearly all orientations. After trying to find a practical way of mounting it, i gave up lol Its just too big, and one of the elements is exposed at all times to knocks and damage on landings.

Not for me

[mark1975]

Very cool ian it ill be nice to see the results and findings..

[Badlands]

It looks more streamlined & faster to me.

[Coyote]

Yeah definatly more streamlined now. Time will tell :)

[Coyote]

Right been out with Keith today for some cloverleaf testing. The results are mixed :

Both horizontally and vertical Yagi`s had incredible reception throughout the flights, not one bit of interference or break-ups at all !!

The patch antenna ( Circular polorized ) was dismal.

But im chuffed to bits, the reason the CP patch was dismal is because myself and IBCrazy couldnt determine properly wether the patch was RHCP ( Right Hand Circular Polorization ) or LHCP ( Left Hand )

I had to take a guess. If the antenna performed on the Yagi`s and the patch, this meant the Cloverleaf was fine and i had guessed right. If the Yagi`s were fine but the patch not, i had guessed wrong.

Turns out i had guessed wrong, so im making a left hand version in a few hours. Tomorrow im taking to the air with it but this time im absolutly confident all antennas will receiver perfect pictures through the whole flight.

I am seriously impressed with this antenna, its wicked. Im that impressed with the performqance with the Yagi`s that i see now point in making a Bi-Quad or Helical antenna for the receiver yet as they didnt loose any quality at all ( If it aint broke dont fix it )

The only let down was the KX171`s perfrormance, again no matter how much i adjusted it was simply too dark to fly with.

I also tried and sucessfully completed my first Coyotewing hand caught landing, even in high winds :) It was a bit daunting at the size and weight it was but not actually that bad :)

[Devonian]

Ian, good to see you investigsating CP antennas.

Make a 4 leafed Skew-Planar, it has the best 'all round' performance and is a near perfect match to 50 ohm coax cable and has a very uniform polar plot.
Personally, I don't like the 3 leafed IBCrazy variant as it has lobes in it's polar plot.

I've been banging on about CP antennas for some time and currently, the best performance is from a Skew-Planar on the VTx and for enhanced performance a Helical beam on the VRx (both of the same hand polarity).
OMM has now developed a CP patch antenna on RCG.

I made the first Skew-Planar (5.8GHz) and originally made the FPV community aware of the Skew-Planar antenna on the RC-Cam forum, where OMM picked up on it and then made a post on his quadrocopter thread on RCG.
IBCrazy spotted it and popularised it (which is fantastic) and the rest is history...

Check out the threads on RCG where OMM really has done a lot of work (along with a couple of others) using software simulations for optimum CP antennas.  OMM also has a spectrum analyzer to validate the antenna performance after each build.

Watch out for the latest developments on the QFH antenna - this is one I used years ago, but it's not (currently) optimised for best axial ratio - but I think it soon will be, although it's a b*tch to build!

Get some gold plated 'memory wire' from your local beads n bangles shop (don't be embarrased with all the ladies in there ;) ) it really is very tough at 2.4GHz and 5.8GHz.
Use RG316 teflon coax upto 2.4GHz - it doesn't melt when heated with a soldering iron.

Nigel.

[mark1975]

Nice one ian welldone  on the testing ..hope you got the catch on film lol..

[Coyote]

Thanks Nigel, yes blown away with the difference, especially for a first try. I think ill make the Skew-Planar out of curiosity too and go from there just to compare.

Cheers for the wire tip. Ill try that :)

[Coyote]

I went out with Keith tonight, it was too windy for flying but we could at least est the Lef Hand Circular Cloverleaf.

Now, last week the cloverleaf did really well on the Yagi`s but dismally on the patch antenna. I put this down to guessing the wrong polorization. So this week ive fitted the left and off we went.

First test : Plane placed 50 yards from groundstation. Last week this had poor picture quality. This week, perfect picture :)

Second test : On the way back from a call out we went to an idustrial estate. The plane was I stood at one end with goggles, Keith went across a field and switched plane on. If i then got a pictureall was great. What happened was, Keith rang and said he was switched on, i faced the field turned on the goggles and got a perfect picture :) Only thing was the picture was of the industrial estate ??????

What Keith had done was drove 1/3 mile down the lane and switched the plane on with me facing the opposite way 1/3 mile away. Result !!!

What was impressive was a few things:

1) 1/3 mile behind the patch and still perfect picture.
2) Perfect picture at ground level with all the metal industrial fencing creating a mltipath nightmare and
3) The best bit we were not expecting, when keith closed the van door 1/3 of  mile away at ground level, i could tell him what was in the van still because i could still see it just fine :)

Enough to say both Keith and myself were more than impressed, this antenna system is my new favorite thing :)

Heres a pic of where i was stood, if you can count 4 lamposts down on the left thats where Keith parked up.



So whats next ?

Well.................. :)

Im doing another mod to the wing ive not seen done in the UK yet.

Watch this space over the next week or so :)

The next thing ive turned my interest to is diversity. There is not a diversity system out there thats exactly what i want, so im looking into making my own. 4 antenna inputs, down to two, then use a simple eagletree eagle eyes to pick between the two feeds and amplify the signal from there.

[Coyote]

Well.............................

Heres the idea, I wanted a super fast very accurate stabilization unit for the wing. I couldn`t afford a FY21, the DOSD Gps based feature is good, but i wanted quicker. So enter the Wii :)

Loads have fitted the wii controllers to Arduino boards to control tri copters, quads etc. But after Mike sent me a board up, i sat and thought, why can`t you fit one to a plane ?

After searching all over there was an experimental, totally untested code. Keith found this and showed me it. Hmm, untested and never tried before ? .......... Im game :)

Thus began the longest two days of my entire life lol. I had never worked with the code before so that took some learning time and cuppa`s by the hundred. After buying the kit, the first challenge was getting it to work for a wing. After a fair bit of help from Mike we managed to get the controllers ( Wii Motion + and Nun Chuck ) to talk to the Arduino board. Not an easy task as its wired completely different to the normal Wii setup.

Then came the code. There was lots to change, the original code didnt work. I had allsorts of problems from simple rx communication to axis mix ups. For a noob in this field, it was quite a challenge. Again lots of cuppa`s later i finally got it to fire up, read the sensors, let the rc through, switch on tx between normal and auto level.

So heres the requested video of it all working. Its past 3am so very quick, very tired :) I would not go to sleep till it worked and thank god it does :)

In the video i have PID settings very high so the camera can see the elevon movements clearly

First Wii Delta Wing

[mark1975]

Very imprssed matey by god it works lol...