I love my little Goblin but it lands too hot and stresses the foam. So I extended the wings with some short extensions, stepped on top and bottom and now it lands just as fast but with a lot less sink rate and just slides along the ground. It is a bit slower in flight and has nice slow rolls. I enjoy it a lot more now though it has a bit of a strange shape in the air. 1806 motor (tiny and no torque) with 1600mah worth of lipo in the nose. A real glider. Doesn't do loops, no power.

Update 9/29: flew this morning on 800mah battery and got 10+ minute flight.

Built the FT Goblin kit using PVC board which is incredibly strong and tear resistant. But it has no paper on it so cannot do b-fold so had to just cut parts out and glue them together without the folds. Totally screwed up the elevons and made vcut on topside so it will not be as aerodynamic as it should be. Just completed it and will try with a 1806 motor with 6 inch prop. Hope I don't burn motor out. Would really like a 2204 or 2205 but don't have one. Will see. AUW is about 250 grams with two 800mah lipos in it to achieve CG.
Kit was really really cheap where I am and am not sure it is not a rip off from FT.

Update: had maiden flight. Flys nice except it tends to climb on power. Gotta figure that out. Actually I think it is just a little nose heavy which is surprising since it has just two 800mah batteries in the nose as far forward as possible. Motor is very small and light. Best to get a bigger motor and all should be well but I will just slide batteries back a bit for now. Glides great and doesn't stall. Fast plane even with tiny motor but the motor won't last long, too hot after couple minutes easy flying. My flying pitch is a little small now.

I am actually a little bummed now as it seems useless to scratchbuild anymore when such simple, easy, predictable kits like this are available. FT has ruined my scratchbuilding sport. Although, I wish they would make a kit for the T-38 Talon. Guess I still have one more scratchbuild to do.

Moved to Malaysia for a few months and cut my Swallow in half to put in suitcase. Then hotglued it together. Got 10 min and 15 sec flight this morning on 800mah 3s lipo with a few rolls thrown in. It has half KF2 wings which seems to give it more flight time and faster flights. Getting heavy now with so much hotglue, need to find replacement glue for EPP that is light and strong.

Update May 8: flew two batteries exactly 00:10:45 minutes on each. Some wind today so I think 11 minute flight is possible.

Haven't flown for months. My batteries are old and worn out but still got 8 minute flight on 800mah lipo that is old and bloated. Need new ones but we may be going to Malaysia for a few months soon so it will have to wait. Have replaced fuselage and tail from the original - now more room for battery inside but the ESC still needs to be outside for cooling. Using slowfly type prop 8x6 which works quite nice.

Lighting Wing Plank Flight (8 min 56 sec)

This may interest the aerodynamically erudite - it's over my head.

A New Theory of Lift (6 min 17 sec)

I got in a couple outside loops and some other stuff.

Update 7/1: tried some wooden dowels taped to leading-edge - seems to stabilize a bit in wind but draggy. Took them off. Plane flies terrible in wind and uses the battery quickly. Will try a wooden flat for leading-edge and see if that helps. Plane flies nose up a lot but glides nicely. Not sure if motor angle or CG. I think it is a little tail-heavy.
Found out it will definitely not fly without the tail, it just starts spinning to the left into a death spiral.

Update 7/3: a sharp leading edge definitely hinders performance and makes wing twitchy. Took flats off the leading edge and instantly it flew better with the round leading edge. Also found out that the battery was sliding back 3 cm after takeoff and that gave nose-up attitude. Now flies pretty good - just not for very long on an 800 mah battery - about 5 minutes.

Delta Wing Rolls, Inside and Outside Loops (3 min 17 sec)

Short video of just the landings. Full back elevons and the wing just parachutes to the ground. Perfect for my flying area as there are just weeds and no smooth landing space.

Delta Wing New Elevons Landings (0 min 26 sec)

Long video of flights with new bigger elevons. Flies pretty nicely now. Not a great looking wing though - looks like those paper airplanes we folded as kids.
The delta shape is good for stalless landings, unlike my wings which fall off to one side when I fly them too slow. But any wind makes mine waggle a bit.

Next plan is to try faking some conical camber on the front of the wing to control the wing waggle and maybe negate the need for reflex.

Delta Wing with New Elevons (7 min 36 sec)

...Continue Reading

Have one last sheet of 9mm EPP foam and decided to make a new delta wing. I want all the electronics enclosed in the fuselage as my other wings fly nice but have exposed wires and stuff.

The fiberglass pole section runs length of the fuselage underneath for protection. Has two lateral carbon fiber spars. Wings are flexible in the lateral direction but not unnecessarily so.

2212/1400kv motor with 8.6 prop, prop saver, 20amp esc, 3s 800 mah lipo. 9 gram SG92R servos.

The drawing on top was for another design that I decided to forego.

Wing area 451 inches and 15oz weight. WCL = 2.7.

Laminated the balsa elevons and the tail. Taped the leading edges.

Lots of room in the fuselage to move the battery to and fro.
The tail just slides into the fuselage so easily removable for transport on my ebike.

Update 6/25: had maiden. Flies, but lots of problems. Elevons are too small to give good authority. So goodbye to my nice balsa elevons. Prop is terribly out of balance. Glides nicely and is stall proof but under power is doing weird stuff.
Elevon size was 1/10 of wing so will increase size to 1/8 or more.

Plank was pulling to the left during flight and finally figured out it was wing warp when I put the laminate on the ends of the wings. So got a hair dryer and twisted the end of one wing till it looked about right. Now if flies beautifully. Very fun wing to fly. Loops and rolls and carves like a skier. No wing wobble now and the bigger motor and prop gives it lots of torque.

Faster wing than in the original configuration. Also I replaced the flimsy tail with a large vertical fin that works and looks better than original. Had to install the 30amp ESC on top of the fuse as it got too hot inside and shut down. 7 or 8x6 prop works great. Replaced 1908 motor with 2212 1400kv.

Need to patch wing end and laminate for protection as I only have weeds to land in. No flying fields here anymore as university football fields all shut down to public.

Skip to end of video for dramatic landing.

Modified Epp Lighting Forward Swept Plank Loops and Rolls (8 min 5 sec)

Remounted motor mount so that it angles down couple degrees but I think I over did it - however, it flies now but flies crabbed wise under power due to motor angled too far to right now. It rolls to the left even with power off.

Anyway, this is just a bunch of launches, flying around in circles, one crash and landings. Will work on motor angle some more. The 2200kv motor is too fast for this model so will put on a 1400kv with 8 inch prop and that should be just right.

I cut the elevons down and unfortunately it doesn't do a decent roll now. Seems it needs full length elevons to do rolls.

Still love the way this plane flies and looks in the air. Nothing like a forward swept wing.

Update: found that right elevon horn was almost broken away from elevon. That explains the left roll even with power off - nothing to do with motor angle. So waiting for next flight and expect it to be a good one.

Update 6/16: turns out that fixing the elevon horn did not correct the severe left roll problem. Now I believe it is due to a wing warp caused when I ironed on the laminate to the wing. Before figuring that out, I realigned the fuselage on the wing, and took off the old tail and replaced it with a simpler one only on top of the wing. Then I heated up the laminate and twisted the wing to see if I could straighten it. Will find out on the next test flight,

Dancing Wings Lighting Forward Swept Wing - New Fuselage - Day 2 (13 min 57 sec)

Haven't flown much lately so:

After so many modifications to my Lighting wing, it was getting way too heavy for the little 1908 motor that came with it. So I scrapped together a fuselage, shorter, wider and deeper, to put my 30 amp ESC inside. Mounted 2212 2200kv motor with 6 inch prop.

Used a plastic spoon to scoop air into the vent for the ESC.

Unfortunately, the motor mount angle is way too high and it just climbs with acceleration so will remount the motor mount at a reasonable angle. The flight was short so I finished out my batteries flying my trusty wing.

I laminated the outside half of the wings so with the 3s 800 lipo, laminate, 30 amp ESC, it is around 380 grams, about twice the original specs. But the original has floppy wings and can't do a decent roll so this version should really rock and roll.

Lighting Wing New Fuselage (2 min 45 sec)

These orings used to secure prop to prop adapter are absolutely useless. They would break if I left them on over night. Really dangerous when flying as they would break at any time. So I use 3 rubber bands like the one in top right corner and no problems.
I know some folks like to use slices of surgical tubing too.

Saw this wonderful Depron plane with free plans (in English too) here: https://www.flugmodell-magazin.de/do...-flinky-turbo/

You want a cool but simple, all-purpose parkfly racer? Build Flinky Turbo. (7 min 9 sec)

Using my latest scratchbuilt foamy I am learning to fly high alpha. Not much luck yet but is fun learning. Need slofly prop and maybe to move CG back a bit more. Anyway, onward and upward.

Update 9/20: was too nose heavy so moved battery back a bit and wow, flies pretty cool. Can even land without hitting nose. Can use the rudder a bit better. I found out that if the plane is nose heavy and I use the rudder, it dives almost uncontrollably. But with CG moved back a bit, the rudder works well in concert with the ailerons. Doesn't roll as beautifully as before but I need to learn to fly high alpha anyway. Take my hands off the controls and the plane just flys straight and level. Nice. My batteries are in bad shape but leaving for an island soon so will have to wait on new ones till I return. Anyway, it was fun to make a little progress towards learning 3d.

Learning to fly 3D Foamy Scratchbuilt High Alpha (8 min 36 sec)

This is a Frankenstein version of the Nutball/IFO/Bug/Heart Shaped Flyer/Albatross foam plane. No step, just flatplate.
9mm EPP, all laminated with copy shop laminate, 2212 1400kv motor/8inch prop/800mah lipo/ 350 grams AUW, 23inch WS.
Just maidened and it flies really nice, like a conventional airplane when I want and also can do high alpha and really fast rolls but when I let
go of the stick, the dihedral flips it upright so I don't get lost during the roll.
Needs more flying to get a real handle on it but it is pretty cool.

Fun to fly but ended up in tree. Had to tape together a bunch of fishing pole sections and a walking stick together then stood on seat of ebike
to poke it down but got it back. Love how it rights itself if I let go of sticks. Is a bit too heavy and loops are weird and underpowered for some
reason - too heavy I guess. Maybe so tail heavy that it can't drop the nose easily to loop. CG is rather far back but battery is as far forward as possible so guess I may have to add some weight to nose or just give it some throttle.

Bought this super cheap foam 3d plane kit for $8.50 including shipping (not in USA).
No instructions for build but seems obvious. 2206 motor but don't know size of lipo. I will try 800mah 3s as that is all I have but may be too heavy as
this is 58cm wingspan. At least I can use as template on some EPP foam I have when I destroy it. Bought it to learn 3d flying.

Update: this was an awful kit. Did not fly well and disintigrated almost immediately.
Building a scratchbuilt Bug now with EPP foam.

Flying my new scratch-built wing. Flew just under 14 minutes on 800mah lipo.

Swallow EPP flatplate with modified KFm wing compared with scratchbuilt laminated EPP foam wing

• 800 mah battery for both
• 9 minute flight compared to 14 minutes
• 230 grams AUW compared to 340 grams
• faster landing speed compared to slower landing speed
• needs more throttle compared to much much less throttle required
• less aerobatic compared to highly aerobatic
• cannot fly slow compared to slow and faster flying speeds

A laminated airfoil just totally wins out over a flatplate wing.

Scratch built EPP 800mm foam wing flight (1 min 59 sec)

Laminated my BoneYard VI 800mm EPP foam wing with lightest laminate (.05 mm) which perhaps is a little too light in that it wrinkles more easily when ironing on but wow, this wing is strong - can't bend it. The laminate cannot be pulled off the foam.
Weighs 150 grams total with the laminate weighing 50 grams. Didn't have to reinforce the elevons with spars as the laminate makes them very rigid.
Taped elevons to body with ugly yellow packing tape.

My iron got a little too hot so melted foam a bit in spots. Out of practice.

2204 motor. 15amp ESC. 9 gram servos. 800mah lipo. 340 grams AUW.
Servo wires run inside wing. May put other wires internally too.

An airfoil is so much better than a flatplate. My Swallow flatflat 800mm wing flies about 9 minutes on an 800mah lipo, while this wing flies 14 minutes on the same battery. The Swallow needs almost full throttle while this wing floats around on 1/3 rd throttle. The Swallow (with my KFm modification, has to land faster but this wing will float down to a nice slow flop landing. Swallow weighs about 250 grams while this wing weighs 340. Swallow cannot handle much wind but this wing, well I haven't flown it in any wing so don't know for sure but it probably handles it much better.

Scratchbuilt EPP Wing Maiden Flight (4 min 42 sec)

Building a wing that I haven't made in 6 years. 10mm EPP, 800mm width.
Found out that by wiping EPP with alcohol makes packing tape stick better. Had to tape top and bottom
halves of wings together long enough to hotglue the leading edge.
LE and TE look fairly seamless except for a few spots that I will glue together.

Next step is laminate entire wing to make it crashproof. Waiting on .05 mm laminate film as I want it as light as possible.
Will use 2206 motor and 7 or 8 inch prop. Should be a fairly light wing.

I put a KFM2 step on half of each wing of my Swallow EPP wing. It now flies faster and smoother. Amazing difference. Getting 9 minute flights on 3s 800mah lipo.
Also cut a bowtie around the prop and it reduced the whine by a lot.

1/2 KFm2 Swallow EPP Wing (5 min 16 sec)