On the trip back from Geneseo with Clive in 2010 I was leafing through a book on post-war civil aircraft when I came upon a
photograph of the Portsmouth Aerocar for the first time. I thought it would make an interesting rubber twin, but didn't hold out much hope of finding
a 3-view for such an obscure aircraft (only one prototype was manufactured). Well, all credit to Portsmouth Aviation, who are still very much in business and
have an interesting history section on their web site, including an excellent history of the Aerocar, with a 3-view and many photos. It took
a while to get a plan drawn up, but I managed to get the model finished in time to take it the 2012 FAC Nats.
Wingspan is 28" and the model structure was based on my successful Argosy, though the fuselage was rather simpler, being slab-sided.
1/16" balsa was used for most of the model, including the fuselage box, as I wanted to keep the weight down as much as I could.
The wing is cracked rib construction using two spars, with removable outer panels. The booms sit high on the wings, and the high thrust line
means there there is just room for the rubber to pass over the wing spars on the way to the rear peg.
It is just possible to swing a pair of 7 inch props - they just miss the cockpit. As on my
other muti-engined models I used commercial plastic props (these are standard Peck items) both rotating the same way.
The model is covered in Esaki tissue - all white, apart from the fuselage in black,
so that it would look dark when you look through the windows.
The window material is from two large boxes of Tesco fresh cream doughnuts (!) I don't know what it is, but is thin, light, and has a good stiffness.
Only the two upper corner windows are stretch moulded - all other panels are cut from flat sheet and attached with Formula 560 canopy glue. Paper patterns were
cut first to get the shapes right.
The paint finish is Xtracolor RLM Silver enamel, thinned with dope thinners and all markings are cut from painted decal film.
Final weight came out at 77 grams without rubber or noseweight.
First flights were made at Geneseo after the static judging, and after adding quite a bit of noseweight (I'm very glad I built
a noseweight box into the bottom of the nose block) it flew pretty well. Ideal power seems to be one loop of 1/8" and one loop 3/32" rubber
in each nacelle. It does tend to stall a bit when the power runs out, so I will be playing with the rudder trim tabs and sidethrust to
see if I can get a circling glide, rather than a straight one. Flights so far have been between 30 and 40 seconds, but I'm sure there is more to come.
A postscript from 2013 - there certainly was a bit more to come, as the model flew away at the 2013 Dreaming Spires meeting on Port Meadow, Oxford.
No name and address on the model of course - why would you bother on a scale rubber twin? That will teach me. It was timed at 4 minutes 30 seconds over
the trees on the other side of the river.
I'd been working on fine tuning the trim in the weeks before, particularly the transition
from the powered to glide phase, and reduced the rubber slightly to a single loop of 3/16" in each nacelle, giving a less steep climb out, but longer motor run. I can't face
building another to replace it, as life is too short, and I've got so many other projects I want to do, but I will post the plan on the site
as a free download in case anybody else wants to give it a go.
Here's a nice video to remember it by:
Curtiss P-6E Hawk
This model had a ridiculously long gestation, being started back in 2000 as an enlarged and better detailed version of my successful
Comet 1/24 scale P-6E from 1999.
The bones were rescued from the cupboard in 2011 after a 7 year hiatus - something of a record even for me.
The lower wings were then constructed, as was the fin, radiator and the underfuselage fuel tank.
This is how the model looked in December 2012 with all the covering done. The green paint you can see was used as an undercoat to check
what certain parts would look like under the final paint finish. The wheel pants have been made, and the fuselage radiator and headrest fitted, plus all those
exhausts from plastic tubing. The book shows the model colour scheme. Nice as the Snow Owl paint scheme is, everybody seems to do it (including me on my smaller P-6E),
so I fancied a change.
Finish is airbrushed Xtracolor enamels thinned with dope thinners. Most markings are individually cut from painted decal sheet -
in the case of the wing roundels, a white disc cut with a compass cutter was applied first, then the red and blue sections overlaid. The Indian Head
badge was scanned from the book and printed onto white decal sheet.
Rigging is fishing nylon, so functional, tightened using a hairdryer and painted metallic grey.
Here you can see the underside details including the underfuselage tank.
The only photo I can seem to find of the model finished, complete with pilot, windscreen, prop and tailwheel, is this one, parked next to the Vought SBU to the same scale (see below).
You can read how the model got on at the 2013 Indoor Nats elsewhere on the site - suffice to say it achieved a couple of qualifying flights but required some repairs afterwards.
This is a new self-designed open electric model to replace the Kamikaze. I originally drew the type up as a 1/24 rubber model, which had
a wingspan just under 16 inches. The original plane was very small for a two-seater - there are some good photos on the internet where the crew almost look
too big for the plane! So, I redrew the plan, this time using CAD, in 1/20 scale, which gives a model big enough to suit an Atomic Workshop Voodoo 25 electric
motor. I've never seen a model of the SBU before, but the proportions looked quite good, and you know how I am a sucker for yellow-winged 1930's bipes.
Here is the model before covering - except the lower wing, which had to be covered before fitting to the fuselage. Below are a couple of detail photos of the
lower keel and wing fillets.
I added gussets at the wing rib trailing edges on this model to avoid wrinkles, which seemed to work.
The Voodoo 25 motor is a very tight fit in the crankcase, which had to be hollowed out till the balsa was nearly transparent.
I wicked in some thin cyano to strengthen it. Note the sidethrust, which in the event proved inadequate
to prevent the model straightening out as the power dropped at the end of the flight.
The cowl and crankcase split to allow motor access, with the upper cowl held in place using neodynium magnets.
The finish was airbrushed Xtracolour and Humbrol enamels with markings mostly cut from painted decal sheet. Rigging was from fishing line, as on the Curtiss P-6E.
The model weight came out at 56 grams, so a bit more than I'd hoped. However, the Voodo 25 proved to have just enough power on full throttle to get it off
the ground. The problem I had when trimming at the Nationals was that despite all that sidethrust, the model tended to straighten out at the end of the flight and head for the wall. This
resulted in a badly smashed nose, so I have some repairs to do, and a new dummy crankcase to build, before I can fly it again. Fortunately everything behind the cowling is undamaged.
Anyone remember the Frog Diana glider that I started building during the Wilmot Mansour exhibition back in May 2005? (You can read about it here on my Frog site).
Well, in 2013 I finally finished it. The incentive came from the introduction of a 36 inch span bungee launched glider competition
at the Peterborough Flying Aces meeting. It looked a fun event and with the span of the diana being exactly 36", I thought I'd give it a go.
The model is finished in coloured domestic tissue. not something I do very often. The letters are cut from tissue and applied with dope thinners.
Quite attractive lines I think, and the first glider I have build for about 35 years! It was a bit blustery at Peterborough, so difficult to trim a new model properly,
but it got to the top of the line several times, and put in a couple of reasonable flights. I quite fancy building another three foot glider now. Maybe the Veron Classic?
Beech Super King Air 200
As I've taken the Argosy three times to Geneseo, I thought it would be nice to have a new Jumbo scale model for 2014, and drew up this 40 inch
span Beech Super King Air 200.
It's my first low wing scale twin, but seeing Chris Starleaf's marvellous Grumman Gulfstream last year convinced me that this layout is
nothing to be scared of. FAC bonus points are the same as
for the Argosy, but with only two motors to wind.
The King Air has nice long nacelles, and a huge tail moment - perhaps a bit lacking in wing area admittedly, but kept light, nothing
to be worried about. It's nearly all 1/16" balsa.
The wing centre section was covered before fitting to the fuselage, and the lower stringers added.
The wings detach outboard of the nacelles and I used tongue and boxes as on the Aerocar and Argosy. The nacelles are nice and roomy for the
rubber motors so I
was able to get the rear pegs close to the wing trailing edge.
Note the alternative peg positions.
Here she is with the tissue on, which took absolutely ages, covering the nacelles and fuselage with strips of tissue between
each pair of stringers. The fin and tailplane are covered in black tissue because that's the colour they are on the plane I chose
to model. The props have been test fitted to check for clearance. I ended up removing
about 6 mm from each tip of the Peck plastic 9.5 inch props, taking them down to 9 inch diameter. Still plenty for a 40" span model though.
This photo shows the wing fillet treatment from underneath, plus how I resolved the fuselage shape under the wing.
My originally planned treatment of the cabin windows is shown in the upper photo of the covered model, with rectangular openings.
The idea was to copy what I did
on the Aerocar and cover the window areas with thin clear material, then mask the window shapes and paint the whole lot white with
the airframe. It worked well on the Aerocar because the fuselage had flat sides, the top join was hidden by the wing, and the bottom
disguised by the cheatline. On the King Air, despite the window material being thin, the steps all round looked hideous under a coat of
gloss white enamel. I reluctantly decided I'd have to live with it. Then things really went pear-shaped!
the airframe is a big one, so I sprayed two coats on consecutive days. I thin my enamel with dope thinners, so you have to go very
carefully on a second coat. Round the window areas I unfortunately got carried away (more paint to hide the joins!) and the paint
blistered really badly. Just like applying paint remover in fact. I then spent a miserable hour or so trying to wipe off the mess
from the worst affected areas before putting it on one side while I calmed down.
The next day I bit the bullet, stripped off all the glazing and cut the tissue away, nose to tail, along the window line and one or two bays
above and below.
This is what you can see above.
I took the opportunity to do the windows properly second time around by inlaying balsa sheet with correctly shaped apertures, then the
stripped areas were recovered.
And finally here she is with the white areas repainted. Just to be safe I did the additional coats using white spirit as a thinner!
I think is was worth
the effort to redo the windows, even if it did add at least a month to the build time.
The tail was painted satin black over the black tissue - only a thin coat was required to make it look opaque. All the fuselage and nacelle stripes were
cut from painted decal film. The patterns required were worked out by trial and error, then scanned and saved
in the computer, so they could be reproduced and copied accurately for both sides. Because of the length of the fuselage, each stripe
was put on in three sections, so 18 pieces of decal in total for the fuselage and an additional 12 for the nacelles. The tail registration letters were also cut from gold painted decal and applied
individually to the fin.
Somewhat to my amazement, the model flew pretty much off the board, with just a bit of up elevator necessary to achieve a nice climbing right turn.
Power originally was two loops of 3/16" in each nacelle, 24 inches long and braided and the best he best time I achieved at the 2014 FAC Nats was
51 seconds. The climb was a bit fierce though, so I've now reduced the motors to a loop of 3/16" and a loop of 1/8" in each nacalle. This is now
the same as the Argosy,
although spread between just two props rather than four.
I've tidied up the plan and it can be downloaded here if anybody wants to give it a go.
Here's a video taken by Monz Lyons of the model flying at Old Warden, September 2015 - the rubber was getting tired, so it didn't get as high as usual,
but it gives an idea an idea of how it goes.
Beriev Be 12
The loss of the Aerocar meant that my building program in the run up to the 2014 FAC Nats suddenly became very busy, as all of a sudden I needed
a new FAC scale model. The
Beriev had been on the drawing board (well.... in the computer) for a while, but now I had to get on and build it. It is based on
Peter Smart's successful model, being the same size (32 inch span) and
with fin and tailplane sizes copied across to mine. The construction is somewhat different though, featuring cracked rib wings and
tailplane, and a few more stringers on the fuselage.
I also decided to do the military version with the tail stinger, which makes the fuselage much longer than the King Air.
Stringering the hull was rather satisfying.
This was the where the build had reached in May 2014, just a couple of months from the FAC Nats - and I wasn't sure whether I was going
to get it finished in time. As it turned out I did, by the skin of my teeth, with finishing touches being added the day before I flew out.
One change to the original design is that the outer wing panels now have close to scale anhedral, as I heard that Pat Murray had built a
jumbo scale Beriev and that it was stable with anhedral, as per the real one. Fortunately I heard this before I had built the
outer wing panels so I was able to adjust my design. This certainly makes it look more realistic. I used tongues and boxes to locate the
wing panels outboard of the engine nacelles.
There was enough room for two Peck 7.5" plastic props. The spinners are plunge formed from acetate sheet.
One problem I discovered was that with the tail stinger, the fuselage was too long for my model box, so I had to make it removable.
I decided to make the whole tailplane removable, by sliding it out backwards. There is a locating peg at the rear,
and rare earth magnets magnets at the front, plus a horizontal tab. So, it's physically locked vertically, and by the magnets horizontally.
The finish is in Xtracolor enamels - fortunately I was able to find the correct grey colour for the Ukrainian Navy from the instruction
sheet for a plastic kit of the Be 12. Markings were applied to the gloss finish (either cut from painted decal or home made transfers)
before the whole model was sprayed, after masking the windows, with a light mist of Microscale "Micro Flat" water-based varnish.
First flights were at the 2014 FAC Nats, and were a little disappointing. I'm not convinced about the lateral stability with the anhedral. Unfortunately
my trimming efforts were curtailed when the removable tailplane assembly removed itself during a flight, leading to a nose-first arrival,
a smashed radome and broken longerons behind the cockpit. All quite fixable, but I wanted to do the repairs back at home. I'll persevere a bit
longer before resorting to a reduction in anhedral - hopefully I can get it sorted before 2016.
Here's a final picture with the King Air, showing how they compare in size. You may also notice that the King Air has its exhausts fitted in this photo
October 2014 update
It is with much relief that I can report that the Beriev finally flew successfully at the September Old Warden meeting. We were blessed with
perfect free flight weather the whole weekend, so I had another go at trimming it. The flights were always the same - a steady looking climb out, followed by a stall
as the power rolled off. The solution turned out to be extemely simple, though obviously had taken ages to spot - simply to remove the 1/64" downthrust shims, the model
flew off on a circuit of the airfield, and looked very stable doing it. Click here
for a video taken by Monique Lyons of the second successful flight. There is an HD button if you want to see it in better quality.
Watching the video again, I'm sure a little upthrust is needed - the model is obviously being held down at the start of the flight. It's all down to the high thrust line
pushing the nose down. It just goes to show that you never stop learning in this hobby!
This was my first attempt to design a model according to the FAC Dime Scale rules, so simple construction, not too much wood,
and a span under 16 inches. One of the attractions of the Ripon was the swept back wings, which I hoped would contribute to stability
without excessive dihedral. Plus to my knowledge, nobody has done it for free flight rubber before.
Although some of the cross sections are simplified, the outlines are accurate to the scale drawings I used.
Here are all of the major components covered. I used pre-shrunk tissue (steamed on a frame) for everything except the fuselage.
This fairly mild pre-shrinking still allows
some further tightening after covering - the parts being wafted over a steaming kettle, then weighted down onto a flat surface.
Finish is my usual favourite silver enamel - RLM Silber by Xtracolour. The backgounds for all the markings are airbrushed
gloss white enamel (Humbrol) overlaid with discs and squares of painted decal sheet.
Discs and rings being cut using an Olfa compass cutter. Rigging is fishing nylon.
I'm happy to report it trimmed out reasonably easily at Geneseo 2014, after adding some noseweight and additional
right thrust, flying left hand circuits. Ideal power proved to be one loop of 1/16" and one loop of 3/32" rubber, braided
to avoid bunching at the tail.
For a bit of light relief and nostalgia, I built a Mercury Sirocco beginners rubber model after the 2014 FAC Nats.
This is another of those models I remember building with my dad way back when, and it was a really enjoyable build.
It also flew really well, pretty much straight off the board, with just a shim under the tailplane trailing edge needed.
You can read more about the model in Nostalgia corner here, where you can also download the plan and parts sheets.