Topic: Whitehead P-38 Lightning

After much discussion and prompting from a thread in "On the Strip", entitled "Small Twin Suggestions" I've finally got round to starting the Whitehead Lightning.

Power is to be a pair of O.S. Max .15s. One was given to me a longggggg time ago and I've never used it, the other has been very kindly donated by Leccyflyer from here - thankyou! 

These engines aren't the most powerful machines ever built so if it turns out to be too underpowered I'll consider re-engining it with something a bit more manly.

One of the main reasons for building this model is that it is to be quick and simple. I'm currently building a P-51 with sequencing gear doors etc and it's costing a fortune. The P-38 is being built on the basis that it gets into the air quickly and cheaply.

I'm at a loss with regards to the undercarriage or lack of. The model is supposed to be a handlauncher, but the plans show optional fixed gear. I must admit to not being a fan of handlaunching/belly landing and I dont think fixed gear will do the airframe justice. If anyone has suggestions of how to manufacture my own 110deg retracts for this thing then please chip in with a sketch!!!

Changes to the design:

I'm still making the model deriggable, although I'm dumping the attachments at the tail. The booms and tailplane will be rigid, and I'll fit a spacer between the booms when the wings are off. Although it's only 52" span, the configuration makes for quite a bulky model when finished - hence why I'm not building it as a one-piece.
Next to go are the rudder linkages. Instead I'm fitting a pair of mini servos. One in each boom, for each rudder. Ailerons and throttles will be likewise.

So far I've cut out all the wing
ribs, false leading edges, trailing edge and aileron spars, and have made the 2-piece main spars. I need to make 1/16" skins and I'm good to go with the wings.

If anyone wants photos of the build I'll start taking pics tonight of the wing as it goes together.

 

Intresting subject.... Had nearly started one myself sometime ago...  I would stick to the hand lauch idear if I were you... Retracts in such a small model isnt going to be easy and the extra  weight will make it fly like a brick... I have a 52 " Tigercat .. Flys good with no UC... I added a Camera for aerial piccys and the extra weight (about the same as trike retracts) made it almost unflyable and it dropped out the sky with a power loss...    Build it Light and it will be a joy to fly !
  As for hand lauching the power of 2x 15's at full chat will make it a ease... will just pull out of your hands...
 Good luck..

I suspect you may well be right. Come to think of it, I think the rearward CofG shift would be far too much also, given that all three wheels retract backwards 

I've never handlaunched by myself before. Dont mean to sound silly, but I'm right handed and don't know how to launch  :-[

Do I lawn-dart it with my retarded left arm keeping the right hand on the elevator/ailerons or do I give it a much more competant launch from the right hand but with no say on where it goes thereafter???  :-[

Been spoiled with wheels I have 

Enlist an experienced launcher until you have it trimmed -once you know how it is going to behave, you can get your hands back on the sticks as soon as you've launched it.

Glad someone got something out of the small twins thread (I think I started that one!) - I ended up getting deeply sidetracked   by cataloguing all of my plans and magazines as a result of searching for a twin to build. Once done, the urge to build had left me!

Dave S

What about a dolly launcher, few old coathangers, a few spare wheels. Best of both worlds then!

As for hand launching I always use my stronger right hand. I rarely get others to launch for me, don't trust them! As for the left hand on the sticks. (mode2) I would rather cover the throttle/rudder in early seconds of the flight than elevator/ailerons. Less likley to stall that way! And you can throttle back if all goes wheels up! And the plane gets an opportunity to get a bit of speed up before you slow it down with right stick input.

Just a thought...

Thanks for all the tips folks 

I think I'll give handlaunching a chance over some long grass. If I don't like it (read "can't do it"  ) then I'll give the Dolly method some serious thought 

Off out tonight to meet up with some static scale modeller friends, but I'll get some construction pics up ASAP to make this thread come to life a bit more from the modelling point of view 

Thanks again - handlaunching is something I've very little experience of, so your help is most welcome  8)

Why not start offering to handlaunch your clubmates' models-you'll soon become experienced!

Dave

re Hand launching ,
Funniest thing I ever saw was an older guy half running /jogging ,plane held aloft in right hand then he stopped dead and chucked it straight down into the ground about 3 ft in front of him 

Try not to ask him 

I did that once in the snow, worse still I jumped onto the model with my wellies.
Stearman.
Fred Walton, do you remember??

Jamie

From what I;ve seen down the field bad handlaunches kill more models than it ever has any right to. Giving your model to the wrong person to handlaunch can lead to very short, very expensive flights. I've had models thrown right into the ground 6 feet in front of me. I can handlauch anyone else's models no problem at all, but I can't handlaunch my own, and then fly them away from the launch, for toffee. That's what prompted me to make a lightweight dolly for my funfighters, for those occasions when my expert assistant isn't about.

If you have a look in this thread it might give a few ideas.

http://www.rcmf.co.uk/4um/index.php?topic=27805.0

Looking forwards to seeing that motor put to good use

Leccy

Great thread! Thanks Leccy. 

Got some ideas now at least for launching the thing.

Hoping to get the wings together tonight. I'll get some pics posted up too

Ok first pic:

These are the basic parts to construct a wing. Obviously there's a top skin to go on, plus a false leading edge in the region of the engine nacelle/boom......

Here's a starter for ten though. I need to cut lightening holes out of the ribs before glueing though....

sharpened brass tubes

Now Gordon Whitehead explains the wing contruction on his plans. It's not usual way I've done it in the past, but thought I'd do it the way he intended....

First you CA the false leading edge to the skin.


The you CA the ribs to the false leading edge, making sure to get the bottom corners right into the skin


Next you CA the ribs to the skin completely. W1, W4 and W5 are angled such that they stand vertical despite the dihedral. All remaining ribs stand perpendicular to the lower skin.

After this, Mr Whitehead advises that the lower spar should be "slid in". Lets just say I was sceptical......


But knock me down with a feather if it didn't actually work  I must say I'm rather pleased with myself. Possibly the tightest slide in history, but no breakages or distortion. The lower spar is as snug as a bug in a rug.


And here's one of the upper spar fitted too....


Next I have to saw out a section of W7 to W11 to allow fitment of the trailing edge spar and aileron spar. After that comes the false LE at the nacelle then the top skin 

4 and 5, are they meant to be out like that?

Yes it's where the boom sits  :ww

Gerry

I have a question
Are you going to cut holes in the remaining ribs to allow the aileron servo cables to run into the centre fus? Or do you have another plan ?
Just thought I would ask in case it was something you had missed before sheeting it over 

Hi KTR,

Yup I need to cut largish holes in W2,3 and 4. As well as the aileron servos, there will also be an elevator servo in one boom, and also a rudder and throttle servo in each boom.

I appreciate you looking out for me!! In this case however I decided to cut the holes after construction. I realised after cutting W5 - W7 that they were very fragile once fretted out so I opted to leave the remainder incase the sliding spar technique splintered the whole lot. It was a tight fit and I'm glad I left them now, as I've already broken W5 and had to glue it.

A sincere thanks though! Would have been far easier to keep stum and say "I thought that" after it was too late! 

And thanks Pheasant Plucker (I dare not try to say that out loud  ) you're absolutely right. W4 and 5 straddle the booms. The leading and trailing edges of the wing are cut out after top skinning and the boom fits into their place.

I've used the sharp brass tube technique before Cactus - it works great. Don't think I have that option now though, so scalpel it is.....
Plenty more opportunities for punching holes down the booms though 



Thanks for the interest people - keeps me going that does!

a brass tube will easily cut all your holes even after sheeting, best of all their all in line for servo runs

Winner! I'll give it a shot then. Must admit I've only used it so far with the victim piece lying on a hard surface. I'll try it out and go easy on it. Being in a straight line will be a bonus as I can roll paper tubes inside then to save "losing" servo leads 

you can roll the tube in the tube, push it in, and pull out the tube leaving the roll there.
for cutting with out supporting you'll need a sharp tube.
use a scapel to run around inside the tube at a pretty shallow angle.
i hold the knife and turn the tube taking off a tiny amount at a time.
watch your supporting finger, the tube tends to try cutting into it.

when cutting use pleanty of twisting moation and little pushing. you should be cutting one rib at a time before clearing.

the only downside is sometimes the last bit breaks away leaving a tab on the cut part, when you withdraw the tube it doesn't want to come too.

i to bought this plan to build but hav nt got round to starting it yet. your certainly giving me inspiration.
will be interested to see what servos you manage to get into the wings . there dos nt seem much room. id thought of hiding a small servo in the rad on the side of each boom for the rudders is this what your planning on to

Hi Geoff, I remember you bought your plan after me and it arrived first!!

I'm moving the wing access hatches outboards to between W7 and W8. In there I shall fit one mini servo with the arm protruding through a slot in the hatch and a short pushrod to the aileron. The servo will be attached to the inside of the hatch cover. I've done this several times on other models and have been pleased with the results 

The elevator, rudder and throttle servos I intend to fit inside the boom itself directly under the wing, so I can access them with the wings off.

This means I'll have a "wiring loom" in each wing leading to the centre pod where the Rx and battery reside. Might be a good time to think about Ashloks?? There will be 3 servos to plug in on one side and 2 on the other.

No doubt, go for the Ashloks! I've got 8 servos in this wing, wouldn't want to be without them 

Ashloks it shall be then 

Got the second wing built last night. Wont bother with any photos as it's remarkably similar to the other one! 

i hope it's not too similar... :ww

Hay Jamie..

Solo Hand launching once the model has been trimmed is dead easy and can look very impressive to your club mates.

A couple of us at our club have a pair of Twinkles (stop sniggering) powered by twin SC 15. The best and easiet way to launch is to let the engines run up to full power, hold it from adove at point of balance and do an underarm lob..it works every time as the model is always pointing upwards so there is no danger of throwing it into the ground in front of you. It seems a bit strange at first but once youve done a couple of launches you will woder what the fuss was about.

Thanks chaps (and any chapesses) 

Right, I have my aileron servos in and the hatches made. I've just epoxied the wings together this morning and I'm waiting for it to harden up. After that it's on with the top skins (and this step includes the washout as per usual).

I'll wait until I've skinned it and added the true leading edge and wingtips now before posting more pics - there's only so many photos of bits people want to see 

After that, it's just 3 fuselages to go, 2 sets of engine cowlings and..........oh jeez.... what a stupid aeroplane to build 

I'm really enjoying the build so far though. Anyone else with plans kicking around might actually think about this one. I started cutting on Monday(1.5 hrs), did nothing on Tuesday, assembled one wing on Wednesday (1.5hrs), the other on Thursday (1hr). Friday I sorted out the hatches and aileron servos (2 hrs) and this morning I joined them together (5 mins tops). It's taking shape quickly 

any idea on a finishing method yet. it says on the plan that origonal was glass and resin finish are you going with this method or using something like poly c and tissue or glasscloth or good old dope and tissue

  Hi jamie,
           Just dropping in on your build...lovely looking little project.....have you considered using a dolly for take off?...

  Cliff

Hi Geoff,

I'm almost certain I'll go with the original's glass cloth and resin. I already have a stock of both 

Furthermore, when I read the article about the electric conversion done a few years ago he mentioned that the booms were too weak immediately forward of the fins, meaning that he broke the booms on landing. His opinion was that they needed the glass (he'd used solarfilm) in that area.

Had a bit of a setback - I crashed my Harvard on Saturday  :( First time I've crashed anything in years. Only maidened it that morning and had about 45 mins on it. Got some work to do to patch it up before the Lightning picks up speed again.

I did get the leading edges and spars etc sanded to profile, so it's now ready for the top skins sometime this week.

Had a good weekend this time 

The wing is finished apart from glassing.

Must say that when the tips went on it completely transformed it. Unfortunately my DSL connection at home is down (BT has broken my line.... ) and work's firewall doesn't let me Bluetooth my photos or use my chosen photo host.

I have taken the progress pics though so I'll put them up after the weekend 
It's looking quite good so far. Easily recognisable as a P38 wing, which is encouraging! 


Just got the small issue of building 3 fuselages now.

I had thought of building just the one boom and using it as a plug, but I might be as well just keeping it to balsa? As for cowlings..... should I make these from fibreglass? Only reason I'm thinking about it is because there's two of everything.


Can't wait to fly this little thing now 

Top of the wing is glassed now. It's my first attempt at glassing.

I must say I'm delighted with it. Faster than that solarfilm cack and much easier to work with than dope/tissue type finishes.


I'm going to try to get my progress photos up tonight using my father's Broadband connection as BT now require to send a technician round to sort out whatever they've done to my phone line 

I don't want this thread to lose momentum any more than the actual model, as this thread is a bit part of my motivation to work 



I have another question for the more experienced builders......

What paints and fuel proof (glow) clear cotes would you recommend for this thing. If they're available in the UK then even better. Suppliers would be better still 

I have compressed air available and airbrushes ranging from Badger 150 sized from my 1/48 scale modelling up to automotive spray guns for my car and full size aeroplane project. Consequently I'd only consider spraying the model. I've obviously sprayed R/C models before but they have suffered either from high cost of using fine scale quality paints or from durability (fuel) issues from using cheap stuff intended for general purpose work,vandalism etc 

My P-51 build is being built with lost of detail, working parts and general eye candy so I'd like to use the P38 to test run some of the techniques the proper scale builders use 

If you are doing a NMF P-38, an easy technique to achieve a 'panelled' look is to use 4/5 different coloured silvers in acrylic aerosol form (Halfords etc...)................the complete model can be sprayed in 1 colour, then individual panels can be masked off and given a light dust of a different tone of silver.......................once the complete model is done in several colours, it looks V convincing, especially on the smaller models.

The 'metalcote' paints used by the plastic modellers do a similar job and come in small glass jars for use through an airbrush...............these can be buffed to a polished finish as well.

For an O/D machine................Humbrol enamels can't be beaten on smaller models as you don't need much. All the other 'model' paints such as Spectrum, Klasskote & Warbirdcolours all come in larger tins (125ml minimum) so will probably be way too much for the top surfaces of this P-38 Humbrol also do the correct colours for Insignia blue, red & yellow etc.......................a similar alternative are the 'Xtracolour' paints supplied by Hannants.

Fuel proofer..............Ronseal Matt Polyurethane, fast drying wood varnish.............make sure it;s the spirit based one, not the water based. Thinned with white spirit, it sprays beautifully, and if fuel proof up to around 10% nitro.

Hope this helps.

Phil

Excellent.

Have tonnes of Humbrol and Xtracolor at home  8)

I'd certainly never have thought of Ronseal  but I'll take your word for it and give it a go  Many thanks.

I'm painting it as TFC's California Cutie. Sort of a little tribute to downed airshow pilots 

I also think it'll be a good colour scheme for a small model as the yellow spinners and half stripes will be handy for orientation 

Sorry for the delay everyone......

Here are a few more pics of the progress. In truth it hasn't been much work - I'm just not working on it much  :-[


Here's the aileron cut out, hinged and the servo hatch made.


Same thing from on top. The shroud is 1/64" ply. All pretty average stuff. And workmanship 


Still tipless, and one aileron yet to be cut out, here is it stood next to my 63" Top Flite P-47 wing for scale (and yes the Jug wing is being sanded down. It flew wonderfully but I hated the finish because I rushed it  ). The P38 model really is quite small!


Wingtips fitted - and it's suddenly turned into something recognizable as a P-38 wing 


I've made a start on one of the booms. These are the left and right halves of the port boom. There is 3/8" triangular stock to go on the corners at the aft end where the 1/2" stops rearwards. A few formers, thick sheet top and bottom then a razor plane attack to turn the whole thing into a roughly eliptical cross section. 

Very simple but to be honest it's quite a wasteful way to build. You'd be surprised at how much wood you need to build such a tiny model!


Come on chaps....... kick my backside and get me moving again  :-[

Lookin good................

I agree, very wasteful on wood, but for small models, it's MUCH easier to build from big slabs of timber, and plane/sand to shape starting with a basic box, rather than use formers and plank/sheet it to the desired shape...............on something this size, the planking/sheeting would be 3/32" max, and require VERY slim planks........

Phil

Now I've seen that picture of the full size, I'm not too worried about the 'sharp' edges that I seem to get when I add decoration ........................

Nice thread of a nice looking plane.  Keep going 

GG

Now I've seen that picture of the full size, I'm not too worried about the 'sharp' edges that I seem to get when I add decoration ........................

The pics of a 'modern' restoration.....................though the 'original' was pretty, it wasn't quote a neat & tidy............

Yes sorry I didn't quite catch on but Phil's picked up the point.

The Fighter Collection's P-38 as pictured above was rebuilt at Chino, California for TFC and arrived in the UK in 1992 if I'm not mistaken.

It crashed at Flying Legends 1996 sadly.


Despite me wanting to make a silly little gesture towards display pilots such as Hoof Proudfoot who died in that Lightning and hence me chosing that colourscheme especially - I also think it's a cracking scheme for a model aeroplane as the top, bottom, front and back are all different colours