Now called the N3UTRON thanks to YouTuber Richard from 28th St. Air Land & Sea. "why not go all the way? it’s the N3UTRON. its a subtle reference to Ed’s photon, the u glider 3 channel, and andrew’s last name"
Here are the dimension of a 3 channel motor glider made using 3mm and 6mm depron and a woven CF
arrow shaft.
Armin wing construction with 6 x 1mm CF strip spar.
HobbyKing contact glue and hot glue.
Document laminating film wing and tail covering. Scotch Tough tape fuselage covering.
Flying weight is 300g with a 950mAH 2S LiPo
Motor and 5 x 3" prop from the U-Glider
Spring / Pull control
2 x 13g metal geared servos
12A ESC
Wingspan 140cm.
Chord width 14cm.
Chord thickness 14mm
3mm depron version of the wonderful little twin boom Eachine Micro Skyhunter.
Dimensions are similar to the original but with a slimmer fuselage.
1300mAH 3S battery and FPV gear.
CG best around 35mm.
The final version has a shorter nose, reinforced horizontal stab and rounded wing tips
Here is my simple home made wing incidence meter. Used to determine the correct mounting angle for wings.
There is much debate about the correct angle of incidence required for efficient flight but a good starting point is to have the horizontal stabiliser and wing both at zero angle, then adjustments can be made after flight tests.
A4 sized plans - download and print for your own use.
Video explaining how to use the Newton Incidence meter
This is the story of my awesome X UAV One 1800mm wingspan V-Tail sloper.
It was designed to be a pusher FPV cruiser with a unique prop drive mechanism that encircles the boom. However the boom prop gear box was way to noisy and caused vibrations. Bad for stealthy flying and onboard video.
This kit was sent to me by BANGGOOD for review.
While waiting for the motor to arrive I decided to try it as a sloper.
Actually I always intended to reconfigure it for sloping once the review was done.
The poorly designed gearbox really became apparent during my motor maiden flight.
Once that was out of the way it was time to try a tractor motor setup.
Not so good for FPV with the prop in front of the camera, but a much better flight experience.
And finally as a pure sloper with slimmed down fuselage and longer nose,
made from coreplast, hot glue and gaffer tape.
It is now a brilliant sloper that works in light wind, less than 10kn here, and will ballast up nicely for strong winds.
For the last 2 weeks the wind strength has rarely dropped below 20kn. To keep flying I needed to
design something that could handle strong winds. The obvious candidate was a speedy slope racer.
The balsa-pod version of my Ultralight Sloper was available because it was superseded by the mad-flipping Fusion. Here are the mods needed to transform it into a high wind speedster.
V-Tail 1
Many slope racers use a V-Tail, and I had never tried one, so that was my first mod. I used tape covered 3mm balsa, hot glue and guessed the dimensions. The tail servos are down on the tail, which is not ideal. Not so much for the extra tail weight but the added aero drag.
It flew OK but did not track well at all, drifting and wandering side to side. This prototype V-Tail did not provide enough vertical area.
V-Tail 2
Further reading here suggested that my V angle should be sharper, about 110ยบ and the area needed to be increased.
That improved the tracking heaps but I noticed my tail boom was twisting alarmingly when operating the rudder, as demonstrated in the video below.
Rudder function on a V-Tail is not as effective as a conventional vertical rudder because the control surfaces are acting at an angle to the airflow. Most of the force goes into twisting the tail rather than moving it sideways, and the twist is in the wrong direction, a bit like adverse yaw from the ailerons.
Seems like V-Tails prefer more bank and yank style flying.
V-Tail 3
To increase the stiffness I shortened the tail boom by 150mm, cut 20cm off the 1.5m wing and 30mm off each tail section.
The shorter tail boom and smaller tail reduced the flex nicely resulting in much better speed and tracking.
In strong wind you can add ballast to give more momentum and penetration, which results in more speed. With a 2200mAH Lipo plus an extra 50g in metal washers it could handle 30kn flying crazy fast.
These photos show the final dimensions.
Flying weight with 1300mAH Lipo - 500g
Add ballast to taste
Wing - RG15 160mm chord
XPS foam hot wire cut
Covered with document laminating film
Servos - TGY9018 x 4
Strong wind V-Tail sloper overview and flights
Future design for more speed
For more speed I'll need to increase the tail stiffness further and reduce the drag.
My next high wind sloper design will have two tubes glued together for a stiffer tail boom and a conventional tail for less twisting. With a stiffer tail boom I should be able to place the servos in the fuselage for less drag, and run long push rods to the tail.
Weight is not a problem with these slopers, in fact more weight means more speed.
This design was inspired by a friend who wanted to take one of my "retired" planes to learn how to fly. So I gathered bits and pieces together and tried to come up with an easy to fly, crash proof trainer.
It only has rudder elevator and throttle, no ailerons. I wanted it to be as light as possible for slow and easy flight with a big energy absorbing nose and a tough fuselage.
The fuselage was shaped from a 50 x 100 x 370 block of XPS insulation foam and the tail planes are 8mm panels of the same foam. The boom is a Skyshark P4X 7.6mm tube.
The hotwire-cut 170mm clark y wing comes from rescued sections of the drowned Fokker (which now has new wings) Three x 360mm sections were glued together with the tips each raised 120mm. No spars are needed to hold the polyhedral due to the tape covering and large join surface area for gluing.
The nose is soft packing foam covered with tape and completely encases the 1300mAh Lipo battery.
The motor is the original Bixler 2, servos are cheap 9g HXTs, and it has a Plush 18A ESC and HobbyKing 3 channel receiver.
All up weight with the battery adds up to 550g, giving a slow continuous cruising flight time of over 30min.
This plane is very smooth and stable and with correct trim will fly hands off.
At this stage the nose, fuse and wings are almost bullet proof, but the tail planes are a bit too delicate. Thinner sheets of XPS foam are quite brittle so some kind of reinforcing is needed. Both the elevator and rudder have cracked during the test flights so I have added a 0.5 x 3mm CF spars.
Might be better to use depron or corflute for the tail.
Dimensions
Flight video - motor slope soaring
Build video
UPDATE 30 March 2016
After some tough flight testing by my dedicated student test pilot it became apparent that this tail
design was not crash proof enough.
So here is the new tougher tail design made from depron. The tail to boom join has extra foam fillets either side for more gluing area and to raise the elevator a little.
The new wing has more area and less polyhedral for smoother flight.
Two wings on the Tigermoth worked so well I had to take the next step...three wings.
The most famous triplane is the Red Baron's Fokker Dr1.
My wings are stiff enough not to need inter plane struts so I decided to stick to the familiar rubber band mounts. That meant I had to come up with a method for creating a rigid mount for the top wing. I recorded detailed build videos along the way.
SPECS
Top Wing - Top 1.1m, iron-on laminate and packing tape. 0.5 x 3mm CF spars
Middle and lower wings - 950mm and 900mm. packing tape. 0.5 x 3mm CF spars
Airfoil - 170mm Clark y
Fuselage - 6mm depron, 3mm ply nose, packing tape.
I have never been much interested in scale model planes apart from the Tigermoth biplane. Tigermoth World is nearby and for my 40th Virginia and I went for aerobatic joy flights...great fun.
I already had enough practice hot wire cut wings laying around for the build so I decided to have a go. I gathered scale measurements from tiger moth photos and made the adjustments needed for a 1.2m wingspan model.
The fuselage is 6mm depron covered with yellow packing tape to mimic the plane I flew in. I added 3mm ply under the nose to take landing impacts and a 5mm ply motor mounting firewall.
The motor is a Hextronic DT750 which had plenty of thrust, especially with a 4S battery. Prop is 11 x 5.5", ESC 40A Plush. 3000 mAH 3S or 4S Lipo gives 20+ minutes of cruising.
Here are build and flight videos of this great looking vintage biplane. It flies just like the real thing, slow and steady with just enough aerobatic capability.
A couple of things prompted me to try this traditional foam wing cutting method.
1. Thick boards of XPS insulation foam appeared in Bunnings. Either I have been unobservant or they have just recently added this stuff to the product line. 30mm and 50mm thick 1200mm x 600mm boards are available for $12 and $20.
UPDATE 2025: Now replaced with Blue XPS boards at Bunnings. I have not tested it for hot wire wings yet.
2. There was an old PC power supply that was about to be trashed at work and I already had some 0.6mm MIG welding wire for the resistive wire.
I followed some online videos about getting 12V DC from the PC power supply. First time I turned it on the house safety switch tripped, so it went in the bin.
Instead of a mains supplied power source I decided to try using a 3S LiPo, and it worked beautifully.
I'm using a watt meter to keep an eye on battery level, current and consumed mAh
The pine frame stretches the resistive wire across a 750mm span at the front. Tension is maintained by stretchy shock cord at the back.
Voltage is applied to heat the wire via alligator clips and I have an ON OFF switch on the frame. The LiPo connects via an XT60 plug.
Airfoil images and plots can be downloaded from The University of Illinois Airfoil Data Site. To make templates the airfoils need to be resized, printed then cut out of a rigid heat resisting material. I'm using 3mm MDF board but G10, formica and carbon fibre are also used.
The MIG wire broke mid cut a couple of times so I changed to 40kg stainless steel fishing wire and it's working well. It's 7 strand and nylon coated so the coating needs to be stripped off. I burned it off but it can also be easily peeled off using a knife.
Here's the "How to" video including a test flight.
As these wing cores are solid foam there is nowhere for the spar to fit.
This video shows three ways to form a spar channel.
UPDATE Jan 2016
I am now using a 4S Lipo for more heat in the wire, enabling a faster and smoother cut for 850mm wing halves.
The wire needs about 5A to heat up enough for cutting. I use 4S for my 850mm big bow, and 2S for my 40cm small bow.
Also changed to single strand 40kg SS fishing wire, which has resistance value of 4 Ohms per metre.
I have changed to thin aluminium sheet (window flashing) for the templates. Can be cut out with scissors.
I need to share my experiences with these DT750 motors. They are well suited to tricopters but do have some design faults which need to be dealt with first.
ESC wire support
The 3 wires are not flexible, just continuations of the single core windings, and will break with bending and vibrations. To prevent this they must be supported around the base with big blob of epoxy glue. I used 5min Araldite and it worked well.
Motor shaft "pull-up" The shaft is about 40mm x 4mm and threaded. In theory you don't need a vibration inducing prop adapter, just a nyloc nut. BUT unfortunately the shaft is not rigidly fixed to the motor bell. Tightening the nut enough to stop the prop slipping pulls the shaft up through the motor bell. This increases the bearing friction making the motor heat up and draw more current. The shaft is only held in the bell by one tiny grub screw, which is not enough to resist the "pull-up" from the prop nut.
I had some nasty crashes caused by a slipping tail prop because I couldn't tighten it down enough. Broke an arm and ruined an expensive digital servo.
The solution is to put a nut onto the shaft right down to the unthreaded part, then a washer, prop, washer and nyloc nut. That way the prop doesn't push down on the motor bell. Unfortunately I had already cut the shaft too short before I discovered this problem so have had to resort to bulky 4mm prop adapters.
Quest for the best propeller Turnigy Slow Fly 10x4.5 props are OK but very thin and flexible.
10x5 Gemfan Carbon nylon Graupner copies from Banggood are much stiffer but less efficient giving shorter flight times.
Emax 10x4.5 props from Banggood are a bit stiffer than the Turnigys and may be the perfect choice. Testing continues.
This twin boom pusher is similar to the 1.3m Depron Spectre, however it has a straight 1.65m (65") x 190mm depron Armin wing and twin rudders.
1.3m Depron Spectre and 1.65m Twin Boom pusher
Initially it was designed it as a 1.8m light-wind slope soarer but didn't perform as well as I wanted. The longer tail booms and larger wing span made it too flexy and delicate. I was also comparing the performance to a motorless Phoenix 2000, which is a sensational sloper.
Shortened tail booms and wingspan stiffened up the airframe nicely and the addition of a motor fuselage turned it into an excellent FPV cruiser and medium wind FPV sloper. It tracks well in a straight line and has a decent glide angle but is quite agile like the Spectre.
Instead of using packing tape to cover the depron I used document laminating film, often referred to as New Stuff in the RC world. It is ironed on with a warm iron before bending the airfoil and fuselage, and works very well. It's tougher and easier to apply than packing tape.
Additional strengthening ...
6x1mm CF strip glued along the front of the elevator.
Heat bent UPVC brackets for the rudder to elevator joins.
I used twin rudder servos rather than one servo and a long vulnerable connecting pushrod between the rudders. Full length wing spar made from 2 Skyshark P4X spars joined with an internal CF rod joiner and epoxy.
Here's a quick, cheap and easy vibration-damping camera mount using 2 cable ties and an ID card. It only takes a few minutes to make and greatly reduces those annoying jelly waves often seen in onboard video.
Tools needed are an office hole punch, scissors, side cutters and a marker pen. Materials needed are two small rubber bands, an ID card and two 4mm x 200mm cable ties.
Cut the card in half and punch 4 holes in each roughly 1cm in from the edges.
Double wrap the rubber bands on one card towards the middle from the holes.
Thread through the cable ties to form the springs. Start underneath and thread up out and around the card edges, then back through the bottom card into the middle. Continue on threading in and out the holes till you come back to the start.
Adjust the size of the loops until the top deck is level or possibly tilted forward a little.
Clip off the excess and it's done.
You still need to balance your props but this mount takes care of the vibrations that you can't fix.
Velcro on the bottom is a good way to attach the mount to a plane or even electrical tape for temporary positioning.
Here is the full build in real time - about 4 minutes.
This video shows the comparison of with and without the anti-vibe mount.
Armin wing construction with 6 x 1mm CF strip spar.
To increase the stiffness I shortened the tail boom by 150mm, cut 20cm off the 1.5m wing and 30mm off each tail section.
This design was inspired by a friend who wanted to take one of my "retired" planes to learn how to fly. So I gathered bits and pieces together and tried to come up with an easy to fly, crash proof trainer.
The nose is soft packing foam covered with tape and completely encases the 1300mAh Lipo battery.
After some tough flight testing by my dedicated student test pilot it became apparent that this tail
I have never been much interested in scale model planes apart from the Tigermoth biplane. Tigermoth World is nearby and for my 40th Virginia and I went for aerobatic joy flights...great fun.
1. Thick boards of XPS insulation foam appeared in Bunnings. Either I have been unobservant or they have just recently added this stuff to the product line. 30mm and 50mm thick 1200mm x 600mm boards are available for $12 and $20.
Instead of a mains supplied power source I decided to try using a 3S LiPo, and it worked beautifully.
The shaft is about 40mm x 4mm and threaded. In theory you don't need a vibration inducing prop adapter, just a nyloc nut. BUT unfortunately the shaft is not rigidly fixed to the motor bell. Tightening the nut enough to stop the prop slipping pulls the shaft up through the motor bell. This increases the bearing friction making the motor heat up and draw more current. The shaft is only held in the bell by one tiny grub screw, which is not enough to resist the "pull-up" from the prop nut.
Turnigy Slow Fly 10x4.5 props are OK but very thin and flexible.
