Pistachio scale Vought F4U Corsair

[Rudder flutter]

I started this model a few years ago, but some some reason it got sidetracked and has been sitting in a box. Its about time I finished it, so I have been putting a bit of time into it over the last few days. Its built using the carved foam technic that I pioneered with others about 20 years ago. Last night I hollowed the 2 fuselage halves and stuck them together. Building from foam is not to everyones taste, but its quick and light, and particularly effective for competitive Pistachios as you don't lose points for the under cambered wing section. I intend to complete the model as one flown by VF-17 in WWII. The parts in the photo weigh in at 1.04 grams, These models are so tiny I can't remember if thats good or not!

[Mefot]

The weight sounds good to me although I have no experience of pistachio models.
What type of foam are you using and how thin can/do you carve it ?
I assume it is a messy process !!! 

[strat-o]

That's remarkable.  Does that work out to be about 1/48 scale?  Do you have a solution in mind for the canopy?  If I may suggest it, you can get clear heat shrink tubing that works well.  Simply make a small canopy plug (or use a canopy from a plastic model kit).  Cut a section of shrink wrap tubing, then place the plug inside the tubing and heat it up.  The tubing will hopefully shrink tightly around all contours.  Final step is to cut the finished canopy out.  (Note that certain clear heat shrink materials have excellent optical clarity.)

Marlin

[piecost]

Richard, i have been an admirer of your foam models for some time and will appreciate any details of foam thicknesses and finishing techniques that you may give. Is that gull wing really carved in one piece?

I an especially interested in your paining technique and the resulting weight that is added. With my own attempts at light foam models; i found that that the airframe can be impressively light but the weight soon snowballs with items such as the propeller.

Cheers

Tim

[tom arnold]

While I have never made a flying foam model yet, I have carved a lot of foam forms to use in the Lost Foam process of building a fuselage. I have found that the mess of foam sandings can be almost totally eliminated by wiping the form with a really wet washcloth at regular intervals and doing the shaping over the trash can. The airborne particles are almost totally eliminated but it does slowly destroy cheap sandpaper.

[Rudder flutter]

The weight sounds good to me although I have no experience of pistachio models.
What type of foam are you using and how thin can/do you carve it ?
I assume it is a messy process !!! 

Foam is about 1mm wall thickness on the fuselage, and its a white extruded foam. Floormate 200 by Dow is a good one to use too

[Rudder flutter]

That's remarkable.  Does that work out to be about 1/48 scale?  Do you have a solution in mind for the canopy?  If I may suggest it, you can get clear heat shrink tubing that works well.  Simply make a small canopy plug (or use a canopy from a plastic model kit).  Cut a section of shrink wrap tubing, then place the plug inside the tubing and heat it up.  The tubing will hopefully shrink tightly around all contours.  Final step is to cut the finished canopy out.  (Note that certain clear heat shrink materials have excellent optical clarity.)

Marlin

Its about 1/60th scale I think Marlin! Thanks for the canopy tip. I usually mould my own using acetate and the 'plunge method' (dolly on a stick) but your method sounds easier. I might give it a try. Cheers, Richard

[Rudder flutter]

Richard, i have been an admirer of your foam models for some time and will appreciate any details of foam thicknesses and finishing techniques that you may give. Is that gull wing really carved in one piece?

I an especially interested in your paining technique and the resulting weight that is added. With my own attempts at light foam models; i found that that the airframe can be impressively light but the weight soon snowballs with items such as the propeller.

Cheers

Tim

Hi Tim, Yes, the wing is carved from solid. Not as tricky as it sounds if you persevere. Cut the plan view to shape but slightly oversize, and tick enough, then stick paper template on the front view and start to carve. take it slow, bit by bit and keep changing the blade every 10 mins, and by the end of the evening the hardest part of the model is done. Its one of those things that you can overthink, but just going for it works!

I used to spray enamels, but have switched to Tamiya acrylic, Not sprayed these on foam before, but I'll do a few tests first. I used to spray a base coat first (which tends to raise the snap) then when dry flat off - it tends to act like a sealer, subsequent coats cover easily and smoothly.

[Rudder flutter]

While I have never made a flying foam model yet, I have carved a lot of foam forms to use in the Lost Foam process of building a fuselage. I have found that the mess of foam sandings can be almost totally eliminated by wiping the form with a really wet washcloth at regular intervals and doing the shaping over the trash can. The airborne particles are almost totally eliminated but it does slowly destroy cheap sandpaper.

Great ideas. I have already got into trouble as the foam shavings (statically charged) have clung to the waste basket in the lounge, and half way up my leather chair!

[Rudder flutter]

Got a little more done last night. Cut the wing into the fuselage. The small segment you see in the photos is the belly portion cut away to allow the wing to seat. One advantage of foam, is once the basic components are made, you just cut and fit them together, no need for any local strengthening or internal structures, Its all stressed-skin. Although the Corsairs cranked wing makes it trickier than a conventional low-winger, the advantage of the angles means that no fiddly wing fillets are needed. Its a neat design.

[Russ Lister]

Look forward to seeing this one, Richard.
If it's anything like your Polikarpov it will do well .... is that model still flying btw. ?

[piecost]

Hello Richard. Would you mind giving more details of the foam; its name, its density (if you know) and where to get it? I recall that Floormate 200 was 20kg/m2, there were heavier grades of the blue and yellow foam of 25kg/m2. I think that depron is about 40Kg/m2 (depending on sheet thickness) but have never seen thick sheets of that material.

Cheers

Tim

[Sky9pilot]

When carving or sanding foam, I've found that the dryer sheet when rubbed on the foam will work the antistatic magic.  Keep it handy and wipe down the foam regularly and the static is mostly taken care of.  I buy a couple boxes when I'm at the Dollar Store so the wifey doesn't get made when drying clothes in the dryer!!!
Sky9pilot

[Rudder flutter]

Hello Richard. Would you mind giving more details of the foam; its name, its density (if you know) and where to get it? I recall that Floormate 200 was 20kg/m2, there were heavier grades of the blue and yellow foam of 25kg/m2. I think that depron is about 40Kg/m2 (depending on sheet thickness) but have never seen thick sheets of that material.

Cheers

Tim

Sorry for late reply.
I'm not sure where to get the white foam that I am using. There is a place that stocks it online in London, but I can't remember the name of the shop. This white stuff is a pretty similar density to Floormate 200, maybe just a little denser. Depron is really quite heavy stuff when building tiny models. I did use the thin sheet once though for the wings on a little Martynside Semiquaver. It worked well when heated on one side as it sets a curve in the foam - ideal for airfoils.

[strat-o]

Hi Richard, What tools an techniques did you use for hollowing out the interior of the fuselage?  Thanks, Marlin

[Rudder flutter]

Hi Richard, What tools an techniques did you use for hollowing out the interior of the fuselage?  Thanks, Marlin

Hi Marlin.
The early stage fuselage is made of 2 blanks, cut exactly to side view, and slightly wider than scale on top view. they are joined with little bits of double sided tape. I then use a paper top view template, lightly 'spraymounted' in place so I can cut and sand the top view. So its now correct to top and side elevations, but square section. Its a good idea to then stick another paper template on the nose, circular, for a corsair, and this gives you something to work back from. I don't use templates to carve and sand the cross-section, but have a few photos handy, its fairly easy to guess this part by eyeballing.

Once fine-sanded, the 2 sides are split. I then use a mini-drill with a sanding drum to get it near thin enough. Final thinning is done by wrapping paper around a chunky circular pen or similar. The foam changes shade when you hold it up to the light, so you get a feel for how thin it is. About 1mm wall thickness is OK. the end result looks just like a plastic kit.

Pistachio is a bit of a challenge, but Peanut is a perfect size to try the technique. Pick a model with a bubble canopy and radial engine as a first attempt as the fuselage is easy to get right, similar to a carrot. A P-47 is ideal.

Here are a few pics of an older Peanut Arado I built, taking shape

[Rudder flutter]

Look forward to seeing this one, Richard.
If it's anything like your Polikarpov it will do well .... is that model still flying btw. ?

Sadly I don't have the Pistachio foam Polikarpov anymore Russ. It flew surprisingly well though for such a stub!
Just found these pics in my archive

[rlucas]

Looking good Richard! So you will also have a flying pistachio again for the nationals...? Will have to work a bit harder on mine as well then I think you mentioned at some point you were building or wanting to build one of the racer version Corsairs? In any case nice work!

Regards,
Roel

[Rudder flutter]

Looking good Richard! So you will also have a flying pistachio again for the nationals...? Will have to work a bit harder on mine as well then I think you mentioned at some point you were building or wanting to build one of the racer version Corsairs? In any case nice work!

Regards,
Roel

I hope to have this complete for the Nationals Roel. Yes, you are correct, we talked about the red and white Goodyear Corsair racer scheme a few years ago (when I started the model!) I decided some of the small codes and details were going to be tricky (see pic). I have since made a new fuselage so I can build a WW2 version. I can't decide to go for a British FAA version or a US Navy VF-17 version...Hmmm?
Your Latecoere 26 looks stunning BTW.

[Snaky Stringer]

If you are building a Pistachio, is there an advantage to the clipped wings of the FAA version? For a Peanut there would be, I think.

[Rudder flutter]

If you are building a Pistachio, is there an advantage to the clipped wings of the FAA version? For a Peanut there would be, I think.

Good point Snakey. Unfortunately I built my wing 'unclipped' at 8" span, so conversion to the FAA version will make my model sub 8", but only slightly 

[RalphS]

Beautiful models.  Just some questions. 

 Why make the fuselage joins at top and bottom rather than down the sides which could possibly get partly hidden by wings, insignia, tailplane, etc.? 

What angle do you set the yogurt pot blades on the prop assembly?

Do you have a website showing your art?

Ralph

[Snaky Stringer]

Richard

Do not despair. I have seen photos of FAA Corsairs with unclipped wings - probably when they were still being introduced and before they started flying them off carriers. Just been reading Eric Brown's Wings On My Sleeve and Duels In The Sky, and he has some harsh words about the Corsair as a carrier aircraft. Still rates it above the Seafire, though. Carrier pilots must be tough characters and none tougher than Eric Brown. I think he must have had a special dispensation from Heaven.

[Rudder flutter]

Beautiful models.  Just some questions. 

 Why make the fuselage joins at top and bottom rather than down the sides which could possibly get partly hidden by wings, insignia, tailplane, etc.? 

What angle do you set the yogurt pot blades on the prop assembly?

Do you have a website showing your art?

Ralph

Thanks Ralph
In reality the join does not show once painted. You can see the joint on the little polikarpov as that was left pure white foam on the white areas, but its not a problem. I guess there is no reason why you could not have the split going horizontally, but then again no reason to do this really. The vertical join means much less work on most fuselage types, as the 2 blanks you start off with are identical/symetrical
I go for a 45 degree root angle, with not too much fake-out towards the tip.

No, sorry, no web site, We did produce a how-to booklet many years ago, this may be available online some place. It was written by David Deadman.

[tom arnold]

I hate to get a little off topic but, Richard, your I-16 design was a hit at the last WESTFAC in Arizona. A father-son team of George and Jonathon Nunez took your balsa peanut plan in a 1994 issue of Aeromodeller and enlarged it to, I think, 20"span. They decked them out in Spanish Civil War colors and flew them very successfully. The show stopper flight was an impromptu mass launch between the two and they circled together trying to get on each others tail right in front of the tents----it was very cool. Jonathan got flights of 55 seconds after some initial trimming challenges and was a serious competitor. Interestingly, both planes were very spirally unstable until a couple of tricks were pulled. Jonathon glued a small clear plastic vane right at the front of the cowl which cut down on the effect of the vertical tail. His dad, George, cut down on the actual vertical tail itself and from that point on they flew like piper cubs. You can see the cut-down sheet balsa rudder on George's. In looking at the side view of the airplane itself with that big cowl area ahead of the CG, you would think that it would need a BIGGER vertical tail rather than a smaller one but not so. At any rate, they were tickled with the results as it is a lot of fun to see models fly in spite of themselves.....and it is so gratifying to astound the peanut gallery of experts too!