Here is my JePe FastFoam Build instruction of the Hawker Hunter made from FlyFly EPO parts. Extra JePe parts and materials are added to this JePe FastFoam kit, but you can also buy some more extra options from JePe shop:
- 3D printed Nozzle with internal speed nozzle (normal exhaust is very big..too big!)
- cnc plywood nose gear mounting plate+ steering servo mounting plate+servo
- cnc plywood main landing gear mounting plates
- 3D print of sharper nosecone (3cm longer than standard nose)
- strong suspension landing gear legs and big light wheels
- old school Pilot
- special glassing / finishing materials for EPO / EPP foam models
- Electric landing gear with steering nosegear (4kg version)
The Hunter is quick to build but standard fuselage construction is a little strange and flexibel, but if you are using the extra carbon roving and finish the model in 25 gram glass it will be perfect strong so it can carry a big 8s battery(2x 4s or 1 big 6s). The Hunter does not need much energy to fly so you can take-off from grass and fly very well on a good 90mm 6s setup.
Let’s start with front end of fuselage
Now you have old position on outside(2 lower holes). Draw a new centre line 15mm up and tilt the nosegear plate backwards by 3mm (the 18mm marking on front). Draw the 4-5 mm sleeve so you can cut this out later when you fuselage is finished.
Now you are going to sand all surface that must be glued together. Certainly with EPO and EPP (Elapor) models this is very important do this always on all surface that has to be glued together! EPO foam always feels ‘silky soft’ on outside but that is leftover Paraffin from production: that does not stick very well to any glue!
There is some carbon roving in the JePe kit: use this in topside sleeve before you glue fuselage together. Put in the plywood part and glue these parts together. I used 30min Epoxy from Bison. Also I prepared the inside of my fuselage nose with 25 gram glass and PU-EPO finish: you can see the the ‘yellow color’ from it, it turned out that the sandwich glassed nosecone (after it was also glassed from outside) was super.. SUPER strong! Before you can glas with 25 gram glas you must do sanding of EPO foam surface with 150 paper. It is needed to get good bonding of PU-EPO Finish.
Rear end of fuselage:
use the inner hole of servo and reduce servo arm length ,use servo tester to install them with servo arm in middle position. A drop of CA will hold them in place. I use 13 gram small digital servo with ball bearing and metal outgoing shaft (will put some in my shop)
standard servo setup is mirrored so it will need 2 servo chanels from your receiver (mix program 5 or 6 on my JR). I used some good textile reinforced power tape from Tesa to secure servo extension cable connector.
some sanding of glue surface and some Duct tape to hold it tight together (best test fit parts first before you put glue on them!). I used 30 min Epoxy again to put things together( I used 30 min Epoxy for complete model..)
Time to install the rudder horns: use only first hole and drill it with 1,6mm drill so it fits the kwiklink without free play (free play is the no1 cause for flutter and we don’t want any flutter!) I use CA glue to put them into the EPO foam. Good quality nylon kwiklinks and M-2 thread is coming with our version of this kit (on these small rudders I see no need for Epoxy rudderhorns at a 8s powersetup: as long as parts have no free play. If you want I have selfmade Epoxy rudderhorns for ball bearing or Kwiklink connection in my shop (but you must buy them extra for the Hunter)
Custom made balsa trailing edges are standard in my FastFoam kits: these fit perfect to wing and tail panels. Glue them with CA glue into place (normal tape is OK for short time). Note: the rudders are now all permanent fixed by the balsa trailing edges and we leave it like this: first comes glassing and than finally we free the rudders (picture’s later on)
3d Nozzle print now available from our shop: To place new nozzle: cut fuselage at last panel line . The 3D nozzle has flat mounting side, glue with Epoxy and smooth-out the join with Easy-FoamFiller
To make the 3D print stronger: later outside of nozzle is also covered with 25 gram glass tissue. The PU-EPO Finish does not start melting the nozzle.
Use some tape to pull down the canopy tight to fuselage and there is also some tape between fuselage and canopy (so they do not stick together). Glue surface is sanded a little before 30 Minute Epoxy is applied.needles put some pressure on the sides of the canopy
Nose gear mounting plate:
Optional is this cnc made 7-layer plywood mounting plate with a set of longer m-2 screws to mount the large size 4 kg retracts. Now cut both sleeves in sides of you nose.
I made an extra mounting plate for the nosegear servo: 15 gram servo is an analog metal gear. I use an analog for steering function because an digital servo will ‘sing al flight long’ and use much current. The servo mounting plate is also cut into one side of fuselage nose and glued with epoxy. You can order both mounting plate and steering servo from my shop.
Extra wing screw:
you must glue an extra plywood bracket in wing panel were the screw will hold. The ‘spagetti’ wires will be replaced by a multiple pin connector glued into the foam. I am not sure if this was best location for the connectors so mail me your picture if you find better option
the plug for the retracts need only 1 pulse wire (and pos+ground), the ailerons need 2 pulse wire connections. The retracts are run entirely from a separated UBEC : you use 1x UBEC to feed your receiver and servo’s and you use a seperate one to feed only your retracts. Very important is that the only the white signal wires from your 3 retract plugs are connected to your receiver (this if you use a seperate UBEC for your retracts)
Main Landing Gear: wheels / electric mechanic / plywood mounting plates and strong suspension legs are all optional parts! To save weight I use the Nylon centre blocks for the main gears (strong enough for 3,5 kg model)
important: use a file to make a flat side to the suspension leg so the mechanic can retract without any jamming . The mechanic should always move free to end positions. In case the mechanics can not move free, the current limitter will kick-inn
to get the complete 19mm thick wheel inside the wing it is necessary to deepen the hole. Sanding of EPO is nearly impossible so you need a good cutting tool (use a needle to see how deep you still can go further: you will need full possible depth!)suspension legs for main wing must be 100mm long , wheels maximal 70mm diameter and max 19mm thick.
some 4mm carbon or glasfiber pins can be drilled into the wing and fixed with Epoxy: this to make strong wheel mounting that is anchored deep into the wing. I put 2 pins in the front and 1 in the rear of the plywood plates (drive them with glue deep into the wing)
Join the bottom hatch to main wing: left: cut sleeve in main wing so cooling air can be pulled from cockpit area right: widen opening in bottom hatch to get more air out of cockpit area (there is an nose gear opening in front of cockpit that provides the extra air) now there is air coming from all sides: front/bottom/sides…one big Swiss cheese that will give the scale ‘whoosh sound’ that many are searching for…air will mix into one big airflow and many Fanblades will help me cutting through all these small turbulence’s (not exactly my style but it proved to work after the first flights)
Now its time for finishing this Hunter!
the bottom panel is not the best fitting part..(many EPS-styrofoam parts fit better than EPO). On the picture above I cut some EPO away and use sanding paper and EasyFoamFiller to finish it smooth.
Entire model must now be sanded with 150 grain sanding paper. Surface should not be glossy anymore: surface must be Matt . On places were you can not do sanding it is possible to clean with some aceton or thinner (but best use only sanding paper) only if surface is matt you will get good bonding of 25 gramm glassfibre to your Jet. Use PU-EPO/EPP Finish to paint over the dry glass that is laying ready on the foam surface. scissors / fresh knife / paintbrush / paper-cup with some PU-EPO/EPP Finish and 25 Gram Glass. Please use our flexible 25 Gram glass to keep work easy and keep model light! Do not believe stories about 50 gram tissue: it will make your job on sharp edges horrible and your model heavy as shit! This EPO material is already more heavy(and stronger) than normal EPS foam so keep it light with 25 gram Glass! You need glas that stays were you put it with your paintbrush, find these good working materials in my shop and enjoy working with them. Just paint the PU-EPO Finish over the dry glass (be sure the model is clean before you put any glas on top). There are more pictures on coming Foam-Finish blog so I leave the glassing work to this picture for now.
when model is glassed you can trim off the fiber on the next day Cut the Glass that is hanging over the trailing edge and cut the sleeves free of all rudders remove the glass that was painted over the rudder sleeves (no need to Glass inside the sleeves…only the surface is important) cut the rudder loose with a blade from your iron saw (top picture!)
this looks more scary than it really is: to get rudder moving again it is needed to cut the top layer of Glass Just cut the glas and not any deeper! (just pull the metalsaw blade along the panel line: very easy!) Your rudder will now start to move again. No extra thin hinges are used because the EPO is so strong and they would only make problems
One last cosmetic finishing touch: I don’t like the join between wing and fuselage so I will fill it up with a mixture of Easy-Foam Filler + some PU-EPS Finish(best waterbased PU version). EasyFoamFiller is also very good to mix with some Epoxy
Important before you fill up the gap: first do glassing of your model! the mix of EasyFiller will hold much better on the glassed surface than if it was used direct on to your EPO some aluminium foil in between worked very easy push the paste between the gap and let it harden for a full day.
Time install the Fanunit: I decided to prove the power of one of my new JET90-6s Fans (9 blade version) . This Fan is buildup from a JetFan 9-blade rotor and a different 4-stator housing. Motor is our custom build 36mm motor with Heatsink. Static testbech thrust is some 3,2kgf (31,4N) at max 80 Amps and 6s 5400mAh battery, this is pretty much for only 6s and still an acceptable current. Flying Fans with 100 amps or more makes your flight look like a balloon that you set free: it loops a few times before it is already empty..NOT JePe style of flying!
One extra hole for the power cables that must find their shortest way to the nose as soon as wing is closed you can pull from inside the cockpit on the servo wires and power cables. In my next Hunter I will bring the retract and aileron servo wires more to the front of the wing and go direct into the cockpit without the connector glued into the main wing. (I am already talking about my next Hunter!!)
Leading edge extensions: the outboard leading edges of original Hunter are much sharper and sticking out further than the moulded foam parts of this kit.
sand them nice sharp. Use a sanding block and reduce the 5mm balsa strip to 0mm at wingtip (will have to make better pictures of this). Like JePe you must not be afraid of sharp leading edges! you can still see a little from the extra 5mm balsa extension
Paint Job! first I use a paintbrush to paint the difficult spots, than much quicker with a paint roller. The waterbased Acryl grounding sticks very good to the PU-EPO/EPP finish 10 minutes later !
Fixing the pinholes that you will find at the panel lines use your magic finger and EasyFoamFiller sanding outside : use mask and 150 grain paper The thick Acryl grounding is very easy to sand and surface of model should after some minutes sanding start to look like this
Final paint : I used waterbased wallpaint with metal effect but before I rolled the model with this paint it is wise to use a spraycan in openings were your roller does not come (wheel bays etc.)
spraying with spraycan and rolling waterbased paint over it seems to be no problem (we are in a hurry here!)
Some tuning before we can go flying: The CG (schwerpunkt) must be in this line that you see above (you can follow the panellines on your wing). This is a non critical CG position and no need to bring it further to the front! just horizontal balanced (not nosing down)
Aileron rudder movements:
measure from trailing edge of ailerons: from neutral position they move 10mm up and 10mm down (thats all you need and more travel will make first flight more difficult!) I use 30% Expo on ailerons ( I had to use 85% Dualrate to make the 2x10mm movement I use same 85% on both switch positions)
Measure from trailing edge of elevators 12-13mm up and only 10mm down 9-10mm down (do not make rudder movement bigger!) I use 27% Expo on the elevator function (and again I do not use different dual rates settings: keeps flying simple!)
Your elevators have to move excact same path! on my JR Mixer nr 5 and 6 are designed to run 2 elevator servo’s and keep trim active on both elevators. Also you can tune the travel of both elevators: they must be 100% the same!
Elevator neutral trim seen from side (elevator tip end)
you must trim elevator 100% horizontal. It looks strange at fuselage end but that is only a moulding design problem and should not be used for neutral trimming (look only at tip-end from side for trimming)
First Flights: the Hunter is very easy to fly and very easy to take-off from grass with retracts. Position of Main wheels is very good for fast rotation. Sound of right Fan in combination with this airducting is absolute stunning! It can take 2 blocks of max 5s 4500mAh packs but flies already very scale on a good 6s setup. The EPO material (once glassed with 25gram glass) is really super strong but people who like to give their models a sort of ‘polished carfinish’ will not like the result of the surface unless they role a second coat of grey Acrylic grounding onto the finished skin. I do not care to much because real fighter Jet is not a glamour car and the more a jet shines the easier it stalls…
June 2014 NEW driveset: JePe STORM-90HV (low current high voltage 9-12s)
Video below on 10s 4500mAh and total weight under 3,5 kg! 4kgf static testbench thrust at only 60Amp!
Must use better cam than the Mobius to get the electrifying verticals and big loops on video. Best set video to HD and large screen so you can see and hear something.. Perhaps smartest fan I build in 20 years! (promise I will use better cam next time)