FX707S Albatross - 1.2m foam chuck glider RC conversions

[Simon Chaddock]

MattyB

An LE2204

And a 6x3 folding prop.

[Adrian Smith 1]

nice bit of kit 😀

[MattyB]

15 hours ago, Simon Chaddock said:

MattyB

An LE2204

And a 6x3 folding prop.

Thanks, that does look just right for my intended use. I assume that will be on a 2S pack with an 8-10A esc?

 

will probably get some ordered on AliExpress tonight (they are about 5x the price on Amazon!

[MattyB]

Any more progress @Simon Chaddock? I haven't done much due to some health issues in the family, but should be able to order the powertrain and servos for these at the w/e.

[Simon Chaddock]

Matty

Been working away slowly.

First the elevator servo inset in the fuselage just behind the cockpit.

The servo body just protrudes into the cockpit so no problem routing its wires.

With suitable horns added to the elevator the nylon monofilament pull/pull cables are added.

https://www.youtube.com/watch?v=QbkLFOPYtss

With both aileron servos fitted an "all surfaces" test with the servo tester on "auto".

https://www.youtube.com/watch?v=u5fwHOG0O-s

Still waiting for the motor and folding prop.

 

 

 

 

Edited September 16, 2023 by Simon Chaddock

[Simon Chaddock]

The motor has arrived although no the 6x3 folding prop.

Bench testing showed the notor drew 8A with a 6 x  4.5 on a 2s. It certainly felt like more than adequate thrust.

I printed a motor mount.

 

The nuts are retained by the glued on back plate

 

Those are tiny 10BA bolts!

A printed cowling will match the fuselage to the spinner. It will look somthing like this.

Nothing fixed yet. No point until the prop and spinner arrive.

Quite a bit of effort but I doubt it will make absolutely no measurable difference to its flight performance! 😉 

[Simon Chaddock]

With arrival of the 5x3 folding prop it is virtually finished along with the bits of the original I didn't use.

The folding prop spinner does not really follow the nose profile but it will certainly do.

With a 950 mAh 2s it weighs 286g which is just 7g more than the glider. I am happy with that! ☺️

The completely buried motor does have a bit of cooling.

Single inlet. twin outlets.

The cowling is LW-PLA. 

 

Edited September 21, 2023 by Simon Chaddock

[Simon Chaddock]

My completed FX707s powered glider withall bits in the box that I did not use.

With the folding 5x3 it needed an 850mAh 3s rather than the intended 2s and a 6x4.

After many days of wind and rain I did mange to fly it in near perfect calm but very wet ground conditions.

Sufficient power but after a couple of circuits it lost both power and control which resulted in a rather fast glide into the ground. The very squelchy ground meant a near 'dead stop' landing with the nose part buried in the mud. Of course the controls worked after the crash but the mud in the nose prevented a motor test. It did at least fly.

 

My guess it was the park fly rx that was to blame. it simply lost contact with the HobbyKing TX6i transmitte. I have had this problem before with other cheap receivers.

I note the true Spektrum DX6i is rather more secure with such receivers.

When the modest repairs are complete the Park Fly rx will be replaced by a 'full range' Lemon 6ch 😉

We shall see.

[MattyB]

Did you try turning it on just the rudder? I am trying to decide whether to go r/e/f or add ailerons to mine; mus supicion is it iwll need a bit more dihedral/polyhedral if I go that route....

[MattyB]

2 hours ago, Simon Chaddock said:

Sufficient power but after a couple of circuits it lost both power and control which resulted in a rather fast glide into the ground. The very squelchy ground meant a near 'dead stop' landing with the nose part buried in the mud. Of course the controls worked after the crash but the mud in the nose prevented a motor test. It did at least fly.

 

My guess it was the park fly rx that was to blame. it simply lost contact with the HobbyKing TX6i transmitte. I have had this problem before with other cheap receivers.

I note the true Spektrum DX6i is rather more secure with such receivers.

When the modest repairs are complete the Park Fly rx will be replaced by a 'full range' Lemon 6ch

 

Random question... why do "park flyer" receivers even exist these days? Frsky and many others make absolutely tiny full range RXs that aren't any more expensive than big brand park flyer ones, so why do manufacturers even bother? 

Edited October 3, 2023 by MattyB

[Simon Chaddock]

Matty

Agreed about "park fly" but this particular receiver was "rescued" from a wreck (not mine) a good few years ago. It is however small, light and works some of the time!

[Simon Chaddock]

As a temporary fix I have installed a 35 meg radio!

The long aerial goes down the channel used for the carbon reinforcing and then dangles out the back.

When inside the cockpit the ESC was getting rather warm so it is now outside!

Just need the right weather to try again. 

 

 

[MattyB]

15 hours ago, Simon Chaddock said:

When inside the cockpit the ESC was getting rather warm so it is now outside!

 

 

Just need the right weather to try again.

 

Yeah, that is one of the challenges with a conversion like this; without the moulded vent holes that are always added at the design stage for a purpose built foamie e-glider, the ESC is somewhat entombed. I was already thinking I will vent via the front and back of the canopy and mount the ESC "floating just underneath the underside of the canopy, but that may still not be enough.

[MattyB]

PS - Your last post finally nudged me into ordering the motor/prop/ESC combo for my two models; they should arrive at the start of Nov. They had been in my Ali basket for about a month!

[Simon Chaddock]

With a revised nose paint job I flew the FX707 this morning successfully for 5 minutes despite the rather turbulent conditions.

When I get round to printing a better shaped spinner it will be purple. 😉

My fears of it being under powered with the tiny 5x3 prop were groundless. It has just about the right performance for what is only a fair weather powered glider. It is able to maintain height on a much reduced throttle.  Video at the next opportunity.

 

[Simon Chaddock]

A video of the next flight of the FX707 taken Saturday 7 Oct 23.

I flew it again today for rather longer. It can maintain height on half throttle which should allow 30 minute power on flights.

It does need a bit of down thrust otherwise there is a small trim change power on to gliding. I will incorporate this the next time I have to replace the motor cowl for any reason. 😉

It weighs 320g just 40g more than as a glider.

 

  

 

 

Edited October 9, 2023 by Simon Chaddock

[MattyB]

Good stuff - it looks like it floats quite nicely at that wait, though it's difficult to tell when it was just gliding vs. power on. It also appears to be a time machine, as it was flying way back in 2008! 😉

 

 

Edited October 9, 2023 by MattyB

[Tim Scowcroft]

Hi, we have bought 3 of these 2 have been converted to slope soarers, The have had the wings flattened and 1x3mm carbon spars fitted into the full span slots in the wings, these flattened very easily and hardly show any of the moulded tip dihedral. Each wing has two servos to operate flaps and ailerons. The ailerons are deeper than the moulded positions and the same depth as the flaps. This enables the use of full span ailerons, inboard flaps and crow braking which may seem excessive but why not. The wings and tall were then covered in laminating film to give protection against hanger rash. Imagine yet cove the fuselage before thd first flight.

To accommodate the reciever I freed up the hatch on the underneath of the fuselage which gave access to floor of the area beneath the wing mount. This floor was removed together with about 50% of the wing mount. This created a large space to accommodate the receiver. A hole was cut through to the nose bay, the ball bearings removed and 130grm of lead installed together with a 4cell AAA NiMh battery pack to bring the C of G to the correct position. The hatch is secured using a peg at the front and a magnet at the rear. I installed 9grm servos in the centre of the fuselage below the wing and used piano wire snakes glued into the fuselage slots for the rudder and elevator. I think the attached photos show what has been done.

The all up weight is around 460grm not bad for a light sloper. All I had to buy was the airframe all the rest was in my stock. So all that had to be bought was the air frame which we got for £17 ea. If it flys well. I shall build a second but use the 3D printed motor mounts that are designed to fit thd wings and build a twin.

It is a far better model than the lidl glider which I hzve converted to both a flying wing and a Tilt wing model

What do you think ? Comments please on my efforts.

 

[Tim Scowcroft]

3D printing files

Here are the files for the twin Wing motor mounts

I don't have a printer but a friend is kindly printing them for me

 

motor_mount_round.stl motor_mount_square.stl washer_1.stl washer_2.stl

[Simon Chaddock]

460g?

I know i am obsessed with weight and as a sloper weight can be beneficial but my converted FX707 weighs just 320g with an 850 mAh 3s on board.

I do agree the FX707 is very nicely moulded. It does indeed fiy and glide better than the Lidl by quite a margin.  

[MattyB]

1 hour ago, Simon Chaddock said:

460g?

I know i am obsessed with weight and as a sloper weight can be beneficial but my converted FX707 weighs just 320g with an 850 mAh 3s on board.

I do agree the FX707 is very nicely moulded. It does indeed fiy and glide better than the Lidl by quite a margin.  

 

I imagine it is the laminating film driving most of that weight gain, but on a model of this size on the slope 460g should be absolutely fine.

[Simon Chaddock]

I am seriously thinking of buying another FX707.

Much would be the same but possibly with a 4 servo wing using the existing flap and aileron cut outs but with the tip dihedral transferred to inboard of the ailerons.

Still just "thinking" at the moment.

 

[Simon Chaddock]

By the way I now have another FX707. It arrived today.

Looking at the "as delivered" foam pieces I had forgotten how much I had done to my first one!

At least this time I know what to do so a bit less "thinking" time will be required.

[Simon Chaddock]

With the Bigger Skyray now complete I have made a modest start on the Flapped FX707.

Servos, motor and prop are on order so the detail mods will have to wait until they arrive. Most changes so far are excavating foam out of the fuselage the and removing the redundant plastic mountings as I did on my first FX707.

  

With the plastic and screwed mounting removed the tail plane and rudder are parmanently glued in position.

As before all the flying surfaces will have trailing edge 'extensions' to give a fine 1mm edge. A by product of these extensions is they significantly increase areas of the control surfaces.

As the flaps will be pretty big in relation to the airframe I think I will use my Futaba 35meg Tx as it has a knob to give infinitely variable control to the flaps. 

 

[Simon Chaddock]

The tail plane extensions in LW-PLA.

Elevator has 5 moulded foam hinges which makes it a rather 'stiff' hinge. Two of them have been carefully cut away leaving two outboard and one in the centre.

The rudder has been completely cut away and replaced by a one piece extended Depron one. It is fixed.

 

I am concerned about the flaps. Intended to be ailerons they are top hinged with a substantial "V" notch on the underside.

As a flap it makes more sense to have them bottom hinged with a top link rod. This would eliminate  the substantial "V" notch when the flaps are retracted giving 'cleaner' aerodynamics.

Such a change suggests it might be easier to simply build a new extended flap made of Depron. At the same time it could also be made longer so it reaches close to the fuselage. Such a flap would have 76% more area. 😀

I really need the servos to hand before I do much more to the wing.