Topic: build thread - Mig 1.44 MFI

OK in line with Stueysheeps plea, i'll start a build thread.  First, a bit of background.

I went off modelling in the mid 80s and did other things such as rock music and motorbikes (living in Donington these were compulsory).  A year or two on I married had kids then found surplus time again, usually when soaps are on or those times that pubs used to occupy!  I was always interested in engineering and discovered that gas turbines were now possible for models.  Having built a pulse jet a few years back, i embarked on a phoenix 30.3 /mk4 gas turbine.  Inevitably, model aircraft crept back in and I rejoined my local model club, built a plane with an u/c and did my first take off despite over 20 years of rc flying by hand launching.

Nearly 10 years on and the turbine runs.   Next question is what to put it in.  As some of you know im a tight bottom and i'll build rather than buy.  When I last bought kits, you had change from the paper-round wages when you bought a KK model.   A Eurosport ARTF was £1K+,   B;oody hell, I couldnt buy one of them without flogging the beloved kwaker (not an option).  Having watched Paul Dunkley build his stunning T45 I decided I could do that and stealth purchase would finance it under the ever watchfull financial radar !

I searched the internet for eurofighter drawings but stumbled on this :-


I had never seen any models of this and thought I would have a unique model.  Subsequent research uncovered a beautiful twin engine version built by Christopher Feustel in Germany but this was sadly destroyed on its maiden.  Thanks to his advice, hopefully I might avoid the same problems.

My model is at the "looking like a plane" stage and i'll drip feed the construction pics over the next few weeks.  

Step one, a plan. I bought a revelle 1/72 model and scaled up the dimensions. August 2009 -  Here's the first bit I built the canards (nothing too difficult i thought),
I cut these in foam as a simple delta shapes, covered them in 1/16 balsa after inserting the torque tubes. To get the saw tooth I simply cut a chunk out and repositioned the section backwards.  The tips and TE are in-filled with 1/32 ply to allow sharp but robust edges.

Stay tuned.................



 

I'll be watching this one with interest, loks a cracking subject to model.  

Keith

Subscribed! I'll be watching with interest 

Richard

Looking forward to this Dave 

Paul

Forgot to mention, the model is 1/10 scale making it 1.5m span and 2.2 long, about the same size as a 1/7 eurofighter sport (the actual aircraft is very big).

Being a "secret" russian project, the migs details are sketchy and many drawings from the net differ in several ways. Some show the cannards with dihedral others flat.  The 1/72 model looked right to me and the flat cannards would be simpler.  


 
I have never designed such a complex model model before nor built a jet so any major concerns any of you have as you see it develop feel free to "constructively comment"

The canards only took a weekend to make so I naturally thought I'd have the whole thing finished in a few months (ha ha).  To get a few more simple bits made I made the fins in the same way.  Having cut out the rudders I decided that they were too flimsy being so thin so carved them from solid sheet

I made my mind up that all control would be hidden so decided to use ally tube as a LE for the rudders and as torque tubes into the rear "pod" where the servos would live.

To make room for the servos I fattened up the "pods" or whatever they are called from a scale 25mm to 31mm  I would later decide that this small change made the models bum look big so I rebuilt them to a scale size.  I managed to squeeze in a rudder servo and the servo for elevator/elevon (not decided yet) that sits inboard of the pods.

I made the dorsal fins with foam/balsa but wasnt happy with them.  I remade them with solid 1/2" sheet which was far easier to get the scale scallop shape at the tip.  The lower rudders would be driven by the same servo as the main rudders.

tuning in 

looking forward to this one to see how you go about the scratch build. and it's a great shape.

ps, i sold my kwacka to take up r/c again. 

Once i decided to use torque tubes for the control surfaces,i scanned around the web shops looking for suitable fittings, arms, control rods etc but quickly came to the conclusion that there wasnt anyting suitable for what I had in mind. I decided to make my own torque tube arms out of 12mm dural plate.  They are a close fit to the tubes and will be loctited in position with a 2mm pin for extra security.



I decided on ball joints and found the Kavan ones came in a variety of configurations that looked good but unfortunately also had a lot of slop. Fighteraces supplied some decent yet cheap ones which work well.  I was looking at all metal ball joints which would be best but these arent cheap and given that there is a lot of redundancy (6 elevons, 4 rudders) the loads are shared so the plastic ones should suffice. At 1/10 scale, 150mph is a scale speed of mach 2(ish) so it wont be the fastest jet either.

Next was the short inboard wing extensions and elevators/elevons. Again foam and  3/32 sheet covered to match the yet to be built wings.  Torque tubes pass into the "pods"



Next bits more challenging, the wings......

nice control horns, are they turned up out of a solid piece...

Yep!

Once I got the diameter(s) right and flattened off the arms face, I just turn it about and use a 3 jaw chuck and machine off the other face to the desired thickness.  The rest is shaped with a file and a hole up the centre to lose weight

Dave

Next things to build were the wings. Wasnt too sure of the final layout at the roots so I made them a bit long to be on the safe side.  

The only tapered foam cutting I had done was the bits made so far. The wing was even more tapered. After several attempts I hit upon the idea of a pivot for the hot wire and leave the tip section thicker than desired.  With a bit of sanding, the foam cores looked good.

Spars were carbon fibre tube 25mm and 16mm from Carbonology. as these gave the greatest length before exceeding the foam thickness whilst still looking up to the job.  Couldnt get phenolic tubes to fit them so I made tubes with 2 laps of 1/64 ply. These were set in full depth balsa blocks.

 
Made servo mounts from pcb board for the elevons (ally arms will be used not plastic!)


And inset a ply mounting in the wings before skinning




And skinned them using thin epoxy (epoxydharz L from Electric Aeroplane Co ) on the 3/32 skins and everything available heavy to squash it


Each wing stays like this until the epoxy sets rock hard (48 hours)

 

Great job so far Dave, what wing section did you use and how did you decide it was the right one?

Steve

I had quite a debate about this with Paul Dunkley (an ex tornado pilot) about wing sections.  The 1/72 model shows a section with a top half max section at about 1/3rd but the bottom half with a flatter section but peaking just behind 1/2 chord.  This is not unusual supersonic wings apparently and he felt the plastic model looked realistic.  On the assumption that a flat section canard delta would fly with few vices, "just replicate the plastic models section".  The original plane has drooping LE landing slats but Im not going that far.

Im sure our resident aerodynamic experts may have more to add but i wont be rebuilding the wings!

Dave





 

Next step was to trim the wings skins and put on LE (1" X 1" square), the tip and TE.  After loads of balsa shavings, I had wings! The biggest disappointment was how small these looked. Even a friend said is that the fin!!!

Darn, I hope I haven't made it too small?

I decided that the two control surfaces were to be both elevons and driven from a single 9kg servo.  I also decided that the pushrods would be hidden in the munition rail.  

The inboard surface was made from 2 layers of 1/2" with the torque tube inset.  I used a pair of washer as sanding guides to ensure the LE of the surface was round and concentric with the torque tube.



I used 1/32 ply for the shrouds and built up a hollow section that sits between the surfaces to hide the control arms.



The munition rails


And with the fins starting to look like the finished items!


I had also by now decided how to do the wing roots.  This involved removing an inch section off the wing which would become part of the fuselage plug, allowing me to fair in the fus to the wing stub and obtain a nice wing joint (hopefully).


ttfn

Just as an aside, I have searched long and hard for pics on the internet and think I must have all of them by now.  Only one plane was built and the project axed due to costs.  The plane now sits at an airfield near Moscow and is visible from google earth and or similar.



Some pics were useful, some were ..........different!


 

So glad you've decided to do a build thread on this dave the odd pics you've shown me in the shop have got my interest up so cant wait to see the finished article
chris

I decided that I would make the fuselage by making a plug, taking a mold off it then casting a fiberglass fus.  I also decided to use polystyrene for the plug cos I had loads of 3" and some 6" sheet.  To get the sections I filled up the Revelle model with resin and when it was set, cut it into sections. I separated the intake so this could be made afterwards.  

Slight oversight was the resin started to attack the plastic but luckily it set before too much distortion set in.

Once cut apart,  I scanned the sections on the pc which looked like an squadron of alien invaders.  I scaled them up, trued them symmetry wise and printed each off full size.
 


 The intention was to use a piece of board as a central plain to which I would add each half of the section.  Looked for suitable wood but if it was thick enough to be rigid it wasn’t cheap.  I then thought build each half on a flat surface and join the two halves.  I further simplified it to making full polystyrene sections using liteply formers and hotwire cutting and sticking them together (so much simpler). Aligning reference lines would keep things straight so I thought.





It was at this point I realised I should have cut the plastic model into sections that matched the thickness of the polystyrene !!  I used 10mm which is 72mm, 3 mm less than 3” foam (dammit). Had to trim off 3mm each 3" section or multiples of.

The more complex sections (the cockpit and canards area), I left oversized and shaped these by hand once I had glued root ribs for the canards in place.

Gradually it grew as more sections were added

Looking great Dave 

 The plane now sits at an airfield near Moscow and is visible from google earth and or similar.

Wooo..nice project!!

I was at that airfield in August for the MAKS Airshow, had I known I would have sneaked away from the minders and got some piccies for you .....

Gosh, some more pics would have been nice

Ah well.

Cheers
Dave

I kept adding sections until the fuselage was whole.


The intake area has a separation from the fuselage which I built up from strips of balsa and polystyrene sheet. The air that flows between the intake and fuselage is streamlined towards the wing.



The next step was to add the wings to the fus. I bored out two holes for the carbon spars after measuring (and remeasuring and remeasuring etc).   Once drilled I looked along the model to find the spars sloped with respect to the canards.  After more measurements I decided the fus was twisted and lining up marks on each foam section was no substitute for a decent reference.   I trued things up by breaking apart several joins and regluing with slight corrections.

I then cut out a section to take the wing roots previously cut off the wings



I used lightweight filler to flair in the roots. This worked well on foam and sands at a similar rate to the foam.



Once done, I assembled the whole model.  This is such a fantastic feeling seeing the actual plane appear from a garage full of bits.  I enjoyed the sunshine and admired it for yonks.  Earlier concerns that it wasnt big enough quickly disappeared.  This is how the plane is now so the build thread is now “live”. Further updates will be a little slower coming !!

Cheers Dave

Awesome mate. The speed and quality of your work leaves me gasping in disbelief!

Can't wait to see how this progresses.

Thanks for that.  Dont forget I started this last autumn so its not that quick!!

Dave

Thats one hell of a plane! Wish I had the skill to build something like that.

The build has slowed down lately as im either flying, riding the kwak or being kept busy by work.  Next bit to make was straight forward, the engine intake plug.  This is just a block of polystyrene with a 1/8” liteply at the top. This will be made separate from the fus.



Thinking about skinning the fuselage plug with glass cloth, I decided that some of the detail underneath needed applying first such as the seven scalloped sections that (I presume) holds missile.



Shaping these in polystyrene looked like a recipe for problems and inconsistency of shape. I decided to make these bits in fiberglass and it would be a good idea to learn the craft. I made a single balsa plug of one of the cutouts, painted it, and polished it to a mirror shine using car wax.  I then cast it using whatever I had available eg  layers of wing skinning cloth and wing joining epoxy.  Come to separate it from the plug but it was stuck fast.  I eventually got the two apart but destroyed the plug in the process (dam I had several more to make).  In fact, the paint I applied to the plug was firmly attached to the fiberglass as if I’d painted it.  



I was told that modern car polish contains silicon which makes it stick to resin.  What I needed was the old fashioned solid polish.  I used the fiberglass casting to make plaster plugs so they could be all aligned and the final part made as a set of four.  Polished them with the new wax and had another go. Same problem, paint was stuck so well the pattern was trashed. At least this time I got my part after loads of wet n drying paint off.  Four done, three to go.



I think I’ll have to do a bit more homework on fibreglass. Using thin epoxy doesn't seem that successful even on little bits so I may have to start buying the proper stuff. At the moment the thought of a perfect mold with all panel lines crafted in seems like a long way off !!

Impressive stuff Dave.......

Are you moulding in polyester or epoxy?.........what & how many coats of wax are you applying?

Phil

I used thin epoxy (as its something ive got handy).  The polish I used 2nd attempt is simoniz

I applied a dozen layers over the course of a couple of days.  I suspect the epoxy I used didnt agree with it (the hardner smells of ammonia so may "eat" through the wax to the paint
 
 

Jets are not really my thing but watching this very interesting thread close.  Great work and love to see 1 off's being developed 

Dave

If you are using epoxy and still having issues, I think this does point to the wax you are using.

I've had issues in the past using polyester whereby the heat generated or the styrene content of the resin (never really determined which it was) can attack the wax and soften the paint underneath causing the 2 to stick........but using epoxy, I've had 1st class results.

I use a specialist mould release wax called 'Meguiars Mirror Glaze #8'.......6/7 coats on a fresh mould is all you need, a couple of coats per pull after that works great.

If you're planning on moulding a GRP fuz, I wouldn't risk using anything but the right gear on that, so I'd ditch the car wax...............

Phil

Thanks Phil

Useful stuff

Cheers
Dave

Its been a while since the last update for which I blame the nice weather.  Now the end of summer fast approaches ive refocused on the mig.  I sussed the fibreglass bits in the end and finally made two good scalloped plates for the recessed underside.

To give the whole recessed section a better shape, ive inlayed two 1/16 x 3/4 ply strips to allow a sharper edge. With a bit of lightweight filler, its looking good.

Next step was to fibreglass the whole plug. Ive used 2 layers of epoxy and  lightweight skinning cloth for most of it with glass "tissue" for flat bits.  

After glassing the intake, I quickly realised that glass cloth onto bare polystyrene was expensive in epoxy (it just disappears in the nooks and crannys) so I covered the whole plug in a layer of lightweight filler to make a smoother surface.  

The pic shows the underside freshly skinned, covering up the scallops but these will be cut out once set. 

Cheers
Dave

Progress seems slow at the moment but 2 tins of p38 later I feel I have the plug as close to the correct shape as possible.  Next step is to spray the whole thing with 2 pack high build primer.  1st I have to buy a gazebo as a spray booth.
  






Whilst I get that that sorted i decided to make a tailcone (turkey feathers) plug. I tend to find I need to take a break from large/slow bits and make smaller parts just to feel i'm getting somewhere.

After several attempts trying to simulate the metal plating and failing I decided to use some spring steel sheet (left over from the pulsejet days).  It didnt take long to get an effect that resembles the real thing, even down to the front end covers.  



 

Casting a mould the tail cone plug went really well except the plug was never going to come out!

I dissolved out the foam which then allowed the rest of the plug to be pulled out in bits. I was dead chuffed with the results as the spring sheet sections were all visible.



I then took castings using gel coat, 1 layer of 70g cloth and 1 layer of 190g weave cloth.



Joined these together after trimming and I had my first "proper" glass parts for the plane.



Just got the 2nd one to do then Im running out of excuses for casting the fus!!

I had a change of heart over the canopy. The original intention was to cast this in as part of the fus. Once test flying was done, I was going to cut away the canopy for a “glass” one. I was struggling to get the shapes right at the edges of the canopy and it suddenly dawned that cutting it out would leave it very weak in that area, particularly as the “dashboard” would be missing.   Looking at the drawings, this dashboard is simply a continuation of the nose (much easier to shape!).

I attacked it with a hacksaw and epoxied/glassed the wound. Didn’t take long to start looking right.

Progress has seemed slow but now ive got me a compressor and a spray gun (and the weather is at last suitable for spraying) I can start getting the surface of the plug prepared with 2K primer.  Now its all one colour, its looking like more purpose like.  This pic is after the 2nd coat was applied. Hopefully one or two more should do.  Ah well back to the wet n dry………..zzzzz

Hi Dave

I was wondering if you have calculated where the CG should be yet.

Using a canard CG calculator, I was rather surprised just how far forward it could be.

I am currently building a foam version of the 1.44, (sort of correct(ish) profile, but with some changes to the fuselage shape. i.e. not scale), and it looks like mine will have quite a bit of 'church roof' stuffed right up the nose.

I would be interested to know what dimension you are using as a starting point, related to the wing L.E. as it abuts the fuselage side, (the 'pointy' bit).

Not got as far as thinking about cg yet!  The plan was to build a foamie version to experiment with but i was also considering a  balsa version for a .20. I think the fus underside needs to be about the right area to get a reasonable idea.   

A few friends who I trust aerodynamically estimate the cg to be around the point on the wing where the LE droops start, like you say, alarmingly forward.  The large canards (compared with a typhoon or rafale) contribute.

The chap in Germany who built one used a scaled u/c position and it apparently wouldnt lift the nose due to the forward cg position he had but when it did, it ground looped destroying it.  Needless to say, cg is a concern for mine.

 The twin engined ripmax rapier I had was considerably tail heavy compared to the normal position (some 2" back from std) yet it flew great even at low speed!!

Keen to see yours when it takes shape.
Cheers
Dave

Thanks for the reply Dave.

Initially I ignored the fuselage and just used the canard and wing where it met the fuselage. Later I projected the canard and wing right up to the fuselage centre line.

There was quite a difference. Enough for me to say some rude words 

I used this calculator - http://adamone.rchomepage.com/cg_canard.htm

I hate adding lead to a model I am trying to build light, but this will need something like 6oz to even get the CG near the ball park. Looks like the first flight could be fun.

Here's the last picture I took of mine, (she now has a 'coat of many colours'), I must get round to taking some more.
She's 64" span and 74" long, (It's Ok, I have already been certified for some of my previous electric models  ).

Edit: Errrr, that's a double bed it's laying on, (and almost hiding).

Kin el, I thought you meant a shockie sized foamie. Thats not much smaller than mine!! Looking great!!

Keep us up to date on here!!

I'll have a play with that calculator.

good luck with its maiden
Dave

May the Blue Bird of Happiness fly up your tailpipe.

Took some pictures of my, "It's not a Mig 1.44", (really must think up a proper name).

Here's just one, I don't want to encroach on your thread so may open a new one, though the build is over, but the melody linger on 

Feel free to encroach!!  Very interested in hearing its flying behaviour cg etc

Looks very nice and worthy of being called a 1.44. You could call it the MFI, flatpack, Mnogofounksionalni Frontovoi Istrebitel and even mig35 (before the advanced mig29 became the mig35).

Cheers
Dave

I was thinking perhaps Mad 1.44 or Mug 1.44 

I will post details and hopefully a video of what happens.