[Harry formerly mpx]

It is odd that it has taken me so long to get around to this, my all time favourite aeroplane, but here we go at last.  I bought this kit second hand a couple of years ago and the previous owner had it for some years before that, I think it is one of the early kits so I don't know how it compares to a kit bought now, I don't know if Mick updates them at all.

The first task I undertook was to prepare the retract units.  I do this with any retracts not just these MR ones, and indeed these had fewer faults than the more expensive ones with my AD F-100.  Leaks and swarf are the main reasons for tackling the retracts.  The forward retracting noseleg unit rotates through far more than 90 degrees in order to lift the wheel up inside the upturning fuselage, the main units look like they rotate through a bit more than 90 degrees too, perhaps 100 degrees.
I take the retract units apart and then dunk the cylinders in water and pump some air in each end in turn and watch for bubbles.  A typical leak is around the seal for the pushrod and this can usually be fixed by a squirt of silicon oil into the cylinder, but these units all sealed fine at the pushrod and the end caps.  There was a leak though from the forward nipple on the noseleg, not sealing in the aluminium end cap.  The nipples do not seem to be regular screw in items, but a slightly crude brass tube with a raised ring around them, it looks like a push fit into the end cap.  Soldering around the base of the nipple was not an option since the end cap is aluminium.  The main units are aluminium cylinders and don't look like I could get the end caps out, but the noseleg is a brass tube with push fit end caps sealed with o rings and kept in place at one end by the pivot bolt and at the other by rolled steel pins through the brass tube into holes in the end cap, so it was easy to completely dismantle the nose cylinder assembly.  this was especially good as their was some contamination in the rear end of the cylinder and inside the brass nipple so i was able to thoroughly clean them out.  To seal the brass nipple into the aluminium end cap I dropped on some thin cyano to the joint so it could wick down into the tiny gap then gave it a hit of accelerator.  Further pressure testing under water showed it has sealed fine.  For cylinders I can open like this, I repack the o rings with silicon grease and drop some silicon oil inside before reassembling.  For the ones I can't open, I pop the nozzle of the silicon dropper on the nipple and pull/push the pushrod to suck some oil inside, to both sides of the piston.  Silicon oil can be the stuff sold by BVM, I use silicon oil from motors and rotors which is I think meant for model car shock absorbers.
Then I clean the whole retract assembly and examine it.  The pivot blocks of these units have some rough machining for the slot that the pushrod passes through and there were tiny slivers of swarf in there, and on one unit the machining had pushed the rough edges out onto the surface that the pushrod T piece runs along, so that was removed.  Then all rubbing surfaces are lubricated, I used to do this by rubbing with a very soft 6B pencil but at the moment I use a wax lubricant which is designed to not trap dust and to push it out and carry it away.  Finally it is reassembled with thread locker on every bolt, even on smooth running jets I have occasionally had retract bolts come undone if not locked.
After all that I have retracts which don't leak (at least at the time they go into the model), which don't have swarf waiting to block them, and operate nice and smoothly.
The noseleg forward nipple is installed at an odd angle, pointing at the side frame rather than upwards

Details

So, onto the first bit of construction.  I will need to make a bigger building table than I currently have in order to build the wings, so it is the fuselage first.  This starts with installing the ply formers at the joint between front and rear parts.  It's a whopper of a model, standing upright the fuselage is about 7 feet tall, almost touching the ceiling of my workshop and that is without the nosecone and jetcones.  The joint is not a finely made butt joint such as on my F-104, the forward fuz has a recessed lip to fit inside the rear portion but the recess is crudely defined and the joint will need a lot of filling and sanding later on to hide it.  I want the two formers to mate against each other when the fuz is put together so I have glued in the front fuz former first as it will sit at the back of the recess flush with the rear edge, and then the former inside the rear fuz can be installed at a place to match it.  The fit of the 1/4" ply former to the fuselage is loose - it fits where it touches!

Details

Buy shares in loctite because this is going to need a lot of hysol.  I applied hysol around the inner edge of the fuz and the edge of the former, installed the former then sat the fuz on its rear edge and pushed the former down flat onto the workbench so it is flush with the rear edge of the lip.  Then with gloved hand, I applied lots of hysol from my finger all around the joint and pushed it down into the gaps.  When that has cured tomorrow I can apply more into any remaining gaps from the other side, and I will have a ponder about reinforcing the joint with epoxy glass bandage - these two formers when bolted together hold the large fuz together during high G loads, landing shocks etc so I don't want any risk of them being able to work their way loose.

Details

[CF-FZG]

Ooh, nice one Harry

I've been looking forward to this since you mentioned you'd bought it


Mark

[Dizz]

Will be watching with interest too.  See it at Merryfield next year?
Pete

[Rafale]

Oh Harry!!

it just gets better and better!!
 
Do you want to adopt me as a long lost son?!!    


Cheers

Nige.

[Mark H]

Harry
Glad your doing this thread I'm onto my second one.. Ian Wilde has my original one campaigning it very well and into its goodness knows what season now.......I'm doing a far more detailed one and its so much better to have another brain working on the same project......There are problems to solve but as you know if you persevere with Micks kits you are rewarded with a light extremely scale good flying aircraft....anyway I'll be following your progress and chipping in with questions I'm sure
Regards
Mark

[Harry formerly mpx]

Aha!  If you are the MH I think you are, I was given your email by DS when I bought the kit from him and was thinking of contacting you with a few questions.  I have only ever seen one MR Lightning, at Abingdon and it may have been IW with the one that he got from you.  I had a look at the wing mounting system in the fuz which had been beefed up, the original design does look flimsy for my liking.  There are lots of things I want to consider for amending to my way of liking.

My intention is to add extra detailing like the vents etc.  I have a brake chute for it.  Not sure about panel lines since the original is so well made they are not easily seen, and rivets are near invisible so I can't see the point in replicating them.  What I will do is modify the underlying colour, instead of all black, for the aluminium coating and that will give a panel effect but again the full size was remarkably homogenous in its shading.

I would like a Mk3 most of all - still the small belly tank but the larger, squared off fin, so that mod will be considered.

It will be superb if you take part in this build thread and bring your experience of one already under your belt, as it will if Nmacwarbirds does too.

[The Saint. (Owen)]

What engine will you use Harry? 

[Harry formerly mpx]

What engine will you use Harry? 

No firm decision yet but my thinking is to use a Wren 160.  That is far too much power for straight flight but I can (and do!) throttle back.  The reason for so much power is that the engine is the same size and weight as a 120 so there is no penalty there (though will probably want to carry a bit more fuel for it), and the party trick of the Lightning is to get airborne, raise the wheels and go vertical off the end of the runway.  If it can't do that, it is not a Lightning, imo!  I can't see the point in having a Lightning that can't do that with ease on every take off.  So why carry a 120 that will struggle to do that when for much the same weight I can have a 160 that will do it easily?

My model will be carrying a bit more weight - the aluminium coating requires several layers of paint, there is the brake chute, the twin ring afterburner system, added detail etc.  So I want the engine to have all the oomph I can get.

[Harry formerly mpx]

Some questions for you MH!

Did you use the nosewheel or main wheel brakes, and if the nosewheel brake what did you think of it?

The MR main wheels have no bearing/bushes, just the plain ally hub running on a threaded bolt.  My experience with the Typhoon is that it is not a good idea!  At least oilite bushes would be a big improvement.  Have you modded the main wheel bearings/bushes?  Or perhaps you found it does work ok?

The main oleo springs seem too soft, the model will sit near the bottom of travel.  Looking at pics on MR website, they seem to confirm this, the links are closed as the oleo is fully compressed.  Did you add harder springs?

The oleo link has no travel limit to stop it being pulled straight, so it locks and prevents the oleo from working.  Robart oleos have a metal tab welded onto the leg to stop the link from straightening.  Did you make any mods to the MR oleos to prevent this problem?

The main wheels have foam tyres, I don't know how long those will last!

The tailplanes have one rib in them where the pivot tube ends, so they are very flexible and make me wonder if they will bend in flight when pulling elevator.  Have you found this to be a problem and if so how do you solve it, other than pull the proskin top and bottom apart and build more structure into them?

The top hatch is such a poor fit it almost seems to come from a different model.

[The Saint. (Owen)]

No firm decision yet but my thinking is to use a Wren 160.  That is far too much power for straight flight but I can (and do!) throttle back.

That makes a lot of sense Harry. 

[Pat Barnes]

Looking forward to seeing this progress Harry.

[Mark H]

Harry
The Lightning you saw at Abingdon was probably the one I did it's in the OCU scheme.......The changes I have made on the new one are proper wing tubes which I made up by laminating cloth over the wing tubes themselves....makes a much better rigid structure....main wheel brakes instead of the nose brake...looks like you have the first generation of retracts..new ones are stronger with larger air rams...one major problem is when lowering the gear as the wheel rotates on the down stroke and flat plates to the airflow it sometimes did not lock until the airspeed decayed allowing the wheel to complete its rotation. The video of the airworld version I saw did the same. I have thought of electric or even hydraulic actuation but as the new rams are bigger I will probably leave as is. I have made the airbrakes active and modified the nosewheel steering to cables. I'm considering ballracing the stabs....structure wise mine are ok with foam laminated into the structure which I think was'nt there on my original. The machining on the new legs is better with no resistance to rotation. I know Colin found a couple of problems with his gear when he did the reveiw but mine are fine. I'm finishing up a Vampire T11 at the moment and once done will be back on the Lightning full time.
Mark

[Mark H]

Harry
Just thought of a couple more things....yes the hatch takes ALOT of work you have to cut away quite abit of the bottom of it and P38 to bring the shape back.. time consuming not difficult. Aileron actuation.. I'm using external horns to give a more solid linkage as the distance from hinge to ball link on the original is small. On the two piece fus I have made the join flat rather than having the lip I just found it easier to hide the join. Rudder on my new version is robart hinged with the servo inside the fin with a small external horn... Micks system works but I am going for a more robust linkage same as the aileron. Happy building !
Mark

[Harry formerly mpx]

I'm considering ballracing the stabs....structure wise mine are ok with foam laminated into the structure which I think was'nt there on my original.

Plenty to think about there Mark, I may get better retracts.  I was wondering about using ballraces to mount the tailplanes, the system on my AD F-100 is excellent, with special alumnium holders for the races.

[Bill Stevenson]

My all time favourite aircraft. One day I hope to build one too. 

[JohnMac]

No firm decision yet but my thinking is to use a Wren 160.  That is far too much power for straight flight but I can (and do!) throttle back.  The reason for so much power is that the engine is the same size and weight as a 120 so there is no penalty there (though will probably want to carry a bit more fuel for it), and the party trick of the Lightning is to get airborne, raise the wheels and go vertical off the end of the runway.  If it can't do that, it is not a Lightning, imo!  I can't see the point in having a Lightning that can't do that with ease on every take off.  So why carry a 120 that will struggle to do that when for much the same weight I can have a 160 that will do it easily?

My model will be carrying a bit more weight - the aluminium coating requires several layers of paint, there is the brake chute, the twin ring afterburner system, added detail etc.  So I want the engine to have all the oomph I can get.

Just one question Harry, What is straight line flight?
I think your choice of engine is appropriate, as an underpowered Lightning should attract a fixed penalty notice. I stick in a milkbottle should be an appriate launch method. Good luck with it.

[Harry formerly mpx]

Harry
modified the nosewheel steering to cables.

Yes, I can see that if the leg is not aligned straight ahead as it comes down, the steering peg will not engage in the servo disc.

No work on the Lightning this evening, I have been making the bigger building table to accommodate the Lightning wing.

[Vinceyboy]

Hi Harry, after reading Mark's alterations and suggestions on this lovely looking aircraft, I think it will keep you out of mischief for a while

I remember at the Nats last year, Shane Harding had his lovely Lightning there, whereby he unfortunately suffered flutter on the elevator causing the balance part on the end to snap off, great shame as it was a cracking looking model.

Anyway, good luck with the build

Vince.

[Harry formerly mpx]

I am tempted to make my own tailplanes from solid balsa.  I have found a supplier of ballraces in holders that can be bolted to the mounting plate.

[JohnMac]

I am tempted to make my own tailplanes from solid balsa.  I have found a supplier of ballraces in holders that can be bolted to the mounting plate.

Hi Harry,
Have you considered a balsa lamination? In this way you can choose the thickness of the "core" to be the same as the diameter of your pivot rod which makes alignment very simple. One this and any other bits are glued in the remaing gaps around the rods can be filled and the tailplanes sheeted to make up the final thickness. By altenating the grain direction you can make the whole thing stiffer too.
Regards,

John

[lightning]

 signed in & watching my all time fav jet
   

 early in the day i know but any idea on colour schemes
(schemes being a loose term ) sqd marking prob a better term for the
lightning

 andy

[Harry formerly mpx]

Well, it has to be a bare aluminium finish because I like bare metal jets and I am getting not bad at simulating bare metal, so it won't be a camo or grey scheme (don't think the F1A or F3 were anyway?)  I really like the 111 Sqn Lightning flash on the nose, with black and yellow fin and spine and their crest on the tail, and I already have the graphics on computer for doing that from my F-4.  I also like 92 Sqdn blue fin and spine, with red and yellow arrow head on the nose.  So at the moment, those are the 2 in the lead, my own preference is 111Sqn but that has been done by others, I haven't seen any photos of the model in 92 Sqn colours so that is in its favour.

[CF-FZG]

Are you doing a F Mk 1A or an F Mk 3 Harry?

My favourite would be a 5 Sqn, but a bit hard to see, or my other choice

F Mk 1A - 56 Squadron RAF 1965



or F Mk 3 - 56 Squadron RAF 1966




Mark

[Harry formerly mpx]

The kit is an F1A fin, but I prefer the F3 fin and will consider if it can be modified when I get to that part of the build.  I did the 56 Sqn scheme on my Flair Lightning (XM174 as per your photo!) and it is a justifiably popular scheme which means there are a few models with it and I don't want to have just another 56 Sqn Lightning, which is why it is not being considered.  The only thing I have against the 111 Sqn scheme is that there is a photo on MR's website of Colin Strauss's in that scheme and I don't like to have what other people already have, if I wanted that I would buy a BARF!  That's why the 92 Sqn scheme is attractive to me.
However I do like the second 56Sqn scheme you have shown, with the chequerboard fin and arrowhead on the nose.  That is rarely modelled.  I also like the big red H on the airbrake, good of them to put my initial on the plane!  I think that scheme willbe considered when the time comes to paint it.

These are the other 2 schemes I like:
http://www.clavework-graphics.co.uk/aircraft/ee_lightning/f2_002.html
http://www.clavework-graphics.co.uk/aircraft/ee_lightning/f1a_004.html

[russdelaney]

I like the 92 Sqn

[lightning]

how about this one ??
slightly differant but still got some colour
andy

[Harry formerly mpx]

Nice but it fails the test of natural metal finish!  It's primarily the two-tone grey scheme.

[lightning]

 not a in service scheme but can still do the alli look ,t5 but could be adapted to f3
andy

[Mark H]

Hi Harry
Any progress?.. Can you PM me the ballrace supplier if you get a chance please I was wondering how to mount them......I'm making good progress on the Vampire so I'll be on the Lightning very soon...can't wait....I'm using Micks metalcoat and probably 92 sqn but I do like the OCU scheme I did originally. First time using the foil I was torn between that and the new ali paints with different shades of undercoat....will have to see..I did a test of the metalcoat on one of the stabs and have to say it looks good...I'm a bit of a ludite with PC's so will get up to speed on posting pics of progress so far
Rgds
Mark

[SteveBB]

Had a quick look; no idea which sqns they are, but there's one with a particularly colourful fin... I suppose a T5 is out of the question?  


I double clicked the images this time, and there are two F6's in the photos, the one with teh yellow fin and the one with the black fin.. and teh yellow finned one is grey, sorry! 

[Harry formerly mpx]

Hi Harry
Any progress?.. Can you PM me the ballrace supplier if you get a chance please I was wondering how to mount them......I'm making good progress on the Vampire so I'll be on the Lightning very soon...can't wait....I'm using Micks metalcoat and probably 92 sqn but I do like the OCU scheme I did originally. First time using the foil I was torn between that and the new ali paints with different shades of undercoat....will have to see..I did a test of the metalcoat on one of the stabs and have to say it looks good...

PM sent.
Have you used the MR metal foil on a model that is in use, or just the test piece so far?  I am assuming that the MR foil is the same as Flite-metal, and I have always heard from users that Flite-metal is so soft it gets damaged the moment you start moving the model around the workshop, the car and so on.  Having done an F-86 with BVM metal-kote and recently an F-100 with Sikkens Argentum I know I can get a good effect with them, and pretty hard wearing. 

You can't do 92Sqn, what will I paint mine then!

[Gordon W]

Found this in WH Smiths today.  It's turning out to be a good read even though I do have a ton of Lightning books already.

Gordon

[Harry formerly mpx]

Can you stand the pace of this build!!     I glued another two parts together last night!  Then tonight discovered I should not have    The nose cone should be screwed, not glued to the intake fairing so it can be removed for access.  No problem, got them apart again easily enough.

On my other jets with split fuselages, the fuz moulding wraps inwards at 90 degrees at the join, and a wooden former is placed inside to beef it up, so it is mechanically held in place by the moulding.  On this model there is no inward lip at the join so we rely purely on the glue to hold the formers that bolt the two halves together.  I am paranoid about a former coming unglued so I have backed up the joint with 200g cloth and epoxy resin.

I have been looking at the noseleg.  Steering is done by a long grub screw protruding from the back of the leg locating into a slot in a servo disc mounted behind the leg.  Well that's fine if the leg comes down precisely aligned with the slot, which of course it won't, so the end of the screw will sit on the outside of the disc, leg won't come fully down, will be off centre and won't steer.  Spoke to MR, they now use a centreing spring, I can make one no problem but I still find it hard to believe the leg will come down perfectly aligned.  Unless the slot is wide which means steering slop, chances are the screw will not go into the slot.  I considered screwing another disc onto the servo disc to give it more depth and making a funnel entry to the slot, but the sharp edge of the grub screw is likely to catch on it on its way in.  Or, I could drill and tap the top of the leg for an M3 bolt either side, to use as tiller arms for cable steering but I don't think there is enough room for a servo between the retracted wheel and the front intake lip.
Any thoughts, musings or ideas anyone?

I have been indulging in some Lightning motivation, a couple of weeks ago swmbo and I visited the Midlands Air Museum at Coventry where I took lots of photos of the fine detail on their two Lightnings.  As well as those they have an F-104, F-86, F-100, F-4, what an excellent museum, all my kind of planes!  Was great to see the heat discolouration on the back of an F-100 for real.
Then last weekend we went to Bruntingthorpe open day and stood within a few feet of a Lightning F6 in full reheat as it shot past: the air shook, the ground shook, we shook, the crosswind blew the heat and fumes into us, it was great, swmbo was dead impressed and wanted it to come back and do it again!

[STORM]

Harry, it's a similar setup on the Javelin, with spring works fine, file a radius on the inner top of the servo slot to help guide the pin in. One of those large red arms works best.

[Harry formerly mpx]

Thanks, that's very helpful to know it works well enough.  I know the thick red arms you mean, my Multiplex servos come with them. might add another to double the thickness and make a really wide funnel.

[Mark H]

Harry
Glad to see your back on the Lightning...I've been flying the Vampire I've just finished so once I've splashed some paint on that I'll be onto the Lightning full time..It seems we're having the same thoughts re fus joint and nosewheel steering anyway lets see some pics soon..happy building
Mark

[Harry formerly mpx]

nmacwarbirds has kindly reported that he has had no problems with the steering as per the design, over many flights, so I will continue with that method.

A few weeks ago I spoke to Jim Reeves and discussed a few items.  Starting with the tailplanes, they now make them with a foam lining which makes them much stiffer, although they have no reports of problems with the original.  I bought a pair and they are so much stiffer, it gives me peace of mind, I would always have been worrying about the originals.  It transpires they are not made from proskin over a couple of ribs as I had thought, but are laid up in moulds.  I also bought a set of the main wheel brakes and the disks to modify the wheel hubs for the brake pad.

[Harry formerly mpx]

The two fuz sections are held together by three M4 bolts into blind nuts, though I am pondering whether four would be better as per my F-100 and F-104 purely from the point of view of preventing any rocking, I am sure the three M4 bolts can take the loads.  For now, the two upper bolts and nuts are in place.  The formers have holes in them for the bolts though of course after fitting the formers to the fuz with all the slack etc they have, the holes are well out of line.  I opened up the holes on the rear fuz former until they were big enough to include the true 4mm hole in the front section.  Then I made 1/4 ply plates, curved to the fuselage, and installed the blind nuts on them, then hysoled them into the back of the former, with the M4 bolt in place with penny washers to spread the load pulling them up tight and thus also guaranteeing they are perfectly aligned.  So the fuz is now partly bolted, the one (or maybe I will fit two) bottom bolts still to go.  It's a whopper of a fuz, in this state it is about 7 feet long, without the nose cone, pitot probe or tailpipes in place.

Details

Details

[Harry formerly mpx]

It's time to sort out the servos in case I need to order any.  First of all I calculate what is required by taking various measurements and feeding them into a sophisticated spreadsheet.  After all there is no point in buying JR8511s for everything if they are not needed.

Details

I run the calcs for the Lightning at an airspeed of 200mph, I don't think it will achieve that so it seems a safe top speed to use, but I run the flaps calc at 100mph.

I told the spreadsheet to use a conservative 70 degrees of servo rotation in case of any restrictions, and this has a useful side effect of increasing the torque required so it errs on the side of caution.  The result is suggested to be multipled by 1.3 to give a margin of error and overspec, but I prefer to multiply by 1.5 to give plenty room and as we shall see this still results in surprisingly low demands.

Aileron, 2.8kgcm, so x 1.5 = 4.2kgcm
Rudder, x 1.5 = 6.8kgcm
flap, x 1.5 = 5kgcm

The flap torque is probably way over done, because it lies at 60 degrees to the airflow rather than head on which the spreadsheet assumes, it will generate far less force than is shown.

That's not as much as you expected eh!  Why so much for the slim rudder?  Because its horn is much shorter than that for aileron or flap so it takes more effort to move it.

The plans suggest a Futaba 9001 on ailerons, it's a coreless, analogue, plastic geared servo of 5.2kgcm at 6V so it is a contender as it has sufficient torque, approx £28
The plans suggest a Perkins S136 on the flaps, that is a Supertec low profile servo, analogue, plastic geared, 8kgcm, approx £20

The tailplane is much harder to work out, as the Lightning tailplane is a complex shape to calculate its MAC, and then it is not pivoted side to side like the F-86, F-100 etc but the pivot is swept back like the tailplane.  It probably has a very low torque requirement.

So as you can see, to satisfy the torque demands even at very high speeds, it does not need very expensive, metal geared, monster torque servos.

However....
 The spreadsheet doesn't take account of flutter, that would be very complex to compute.  A servo with just enough torque and small plastic gears may work forever doing the normal job, but lose in an instant if flutter occurs where a much stronger digital servo with big metal gears might hold it at bay.  So there is a case for going up a notch in specification beyond the minimum.  But then again, how far up?  What if you go up in spec but it is still just below what is needed to prevent the flutter that the surface will generate, then the overspec is wasted anyway?

I have a drawer full of servos so I am off now to do an inventory of what I have, and match it up to what the Lightning needs.

[Harry formerly mpx]

The tailplanes will probably work fine with plastic gear standard servo but in case of flutter I think a metal geared, ball raced, digi will be best.  Each tailplane has its own servo so it doesn’t need to be super powerful. It must be from a brand with a history of reliability.  I am considering 3 types of servo that fit that, they are:
Multiplex Tiger MG digi 4  about £52
Futaba S3050 about £34
Spektrum S6020 about £27

Thoughts or suggestions anyone?  I include the Spektrum since afaik it is made by JR?  and it is a good cost saving.  But does it have any history yet, good or bad?  Please don’t suggest Hitec, I won’t touch them, no exceptions, no ifs or buts, I won’t even let them in the house!  I am curious about Hyperion and Savox but am not aware of them being around for long enough under their own brand name, in use in valuable models, to trust them yet on a primary flight control.