It took me several years, but I finally got round to building a Sortsenator Bostonian from my plan elsewhere on the site. As mentioned on the
plan download page here I discovered the centre section needs slightly shortening to keep the span under the 16" limit.
I took out 10 mm, which turned out to be a little more than necessary.
Finish is Esaki tissue, using pre-shrunk tissue for the tail surfaces to avoid warping. To do this, I glue the tissue to a simple hard balsa "picture frame"
using glue stick, and then waft it over a boiling kettle. It then goes drum tight and usually distorts the frame a bit. The tissue is cut out of the frame
and applied as normal. It still retains some ability to shrink after application, which helps with wrinkles, but nowhere near
as much as untreated Esaki.
Prop was a Czech Tern copy, and power one loop of 3/32" rubber. Trimming was satisfyingly easy - it wanted to turn right so I encouraged
it with the fin trim tab, and I just
needed a bit of tailweight to get it climbing up towards the roof of the small school hall we use for indoor flying. Best flights
were approaching 50 seconds. If I could be bothered to scrape the prop,
I could get rid of the weight at the back, and have a lighter model. Anyway - nice to know it flies!
Boeing P.26 Peashooter
As some of you will have noticed, I often tend to build models of aircraft that appeal to me, rather than ones that will be competitive
in a particular class. I've wanted to build a Boeing P.26 for years, and eventually decided to do a Peanut. In its favour is plenty of wing area, but
the chubby fuselage means it was never going to be a lightweight, and those enormous wheel pants looked like they would be very vulnerable in a heavy landing.
The model was based on the larger Doug Wilkey design as it looked accurate, and was a proven flyer at the larger scale. I scaled the plan down to
13" span, using 1/20 and 1/32" balsa instead of 1/16". The wing centre section is very strong, and the wheel pants are glued rigidly to this - I decided
against trying to spring them. All control surfaces were built separately and hinged with soft wire. On this model I constructed
a full set of engine cylinders mounted to a central block, and added a laminated cowling, formed from three layers of 1/32" balsa wrapped round a former.
Once the glue was set, the outside was sanded to a streamline section. This allows you to look through the engine between the cylinders, which is
more realistic than my usual method of solid discs with relief cylinders.
The finish is my usual Xtracolor enamel and markings cut from painted decal, apart from the fuselage badge, which is a printed decal using artwork
from a reference book. Developing the shapes for the gold fuselage stripes was tricky
- a case of trial and error with paper patterns till I got the shape right. Then I scanned the patterns and imported to Autocad so I
could trace and mirror them for left and right hand.
Rigging is fishing nylon, painted metallic grey after fitting.
I'm happy to report it did fly OK at the Indoor Nats, though rather fast, and I got it circling left within the sports hall walls. Best flight was only 21 seconds
from a hand launch, but it's a start. I broke the
outer wing panels off a few times due to taxiing accidents after it landed, so some of the rigging pulled out, but repairs were simple and happily the model came
home still looking fairly pristine. Now to add the mssing engine exhausts!
Chrislea Super Ace Bostonian
Bostonians seem to be ideal models for flying indoors in relatively small halls, such as the school sports hall we visit monthly in Newbury.
So, after finishing the SortaSenator,
I drew up a new model based on the Chrislea Super Ace. When the fuselage was drawn up to meet the dimensional rules, I was pleasantly surprised
to find that it came out very close to scale, and even the wing chord was correct. Of course the span had to be drastically cropped to meet the
16" limit, but that's what
adds to the cartoonish appeal of the class.
The simple structure is evident in this view of the unpainted model. Without the prop, the model is a tail sitter - hence the addition of
a screwdriver in the nose
to keep it on its wheels!
I know it's a bit daft to airbrush a fun model like this, but I wanted to give it a simplified version of the full size scheme. You could, of course, use
silver and blue tissue to do the same thing. Stripes and registrations are cut from blue-painted decal sheet.
You'd think a simple high wing cabin model like this would trim out easily, wouldn't you? Well in this case, no it didn't! I thought the fins looked big enough,
but the tail moment is quite short, so the model was terribly laterally unstable, and could not be persuaded to circle at all until scraps of paper were attached to
both fins using double-sided tape to increase the area. So, I've drawn up a pair of larger fins, and we'll see what happens.
Postscript April 2016
I'm happy to report that the larger fins did the trick, and the model now flies round in stable circuits. So - no excuse to not draw up the plan and put it on the site now!
After doing an in-box review of the Vintage Model Company Jodel D 18 here I couldn't resist starting it, and it
proved to be a really quick build, with all the parts fitting together perfectly. Even the paper pattern for the front cowling fitted really well
(incidentally, the open sides of the cowling proved a useful place to hide noseweight). The large canopy was a good fit, though a bit tricky to trim as
there are no defined lines to cut around - it's a case of snipping off a small bit at a time until you get it right. With such a large canopy I felt I needed
somebody in there, even if he was only a profile pilot. He was actually taken from a photo on the internet of this actual plane - I just cut out a left and
right hand version and glued them together. He should look reasonably effective in the air, anyway.
Here are the model bones before covering - the structure is designed for foolproof assembly with plenty of notches to give a good gluing area.
I sanded off any laser burn marks where they would be facing the tissue. I covered with Esaki as normal
but used it pre-shrunk on the tail surfaces to avoid warping.
Finish is Humbrol enamels with all markings cut from painted decal sheet. Note the trim tab bent up on the right wing to
hold it down in the left hand turn.
After breaking the wing off at Old Warden in 2015, I was able to fly it indoors at Peterborough in April 2016, where I'm happy to say it
circled in a most pleasing fashion.
I found I needed to add a 1/16" sq. gurney strip under the whole of the left wingtip trailing edge (i.e. outboard of the dihedral join)
as well as a tab bent up on the right wingtip trailing edge. This combination cured the tendency of the model to spiral in to the left.
D.H.83 Fox Moth
With the Curtiss Hawk becoming a too familiar sight at the BMFA Indoor Nationals, I decided it was time for something new.
I also wanted to try
something with a lower wing loading than my usual open rubber models, so get a slower, more realistic, flying speed. I'd
fancied having a go at one of the late, great, Dave Rees's designs for a while, so I thought, why not build one and fly it indoors?
The design I chose was the D.H. 83 Fox Moth, a type I've flown successfully before as a peanut scale model. Thus, I had all the
necessary documentation to hand, especially if
I finished it in the same scheme. Span is 29 inches, so larger than normal for me, but I thought it should be fine in a large sports hall.
I started with the wings, as I've never built a set using this construction method before. I used two laminations of 1/32" balsa for
the upper rib caps rather than steaming 1/20" square as shown on the plan, on the basis it would be more robust. The two deep
spars and webbing give an amazingly stiff structure at a relatively light weight (the upper panels are just under 3 grams each).
Changes to the plan involved adding separate ailerons to the lower wings
which would be hinged, and making the lower wing panels separate, attaching to the fuselage sides as per the original, rather than
having a one-piece wing running under the fuselage.
Here is the complete balsa structure showing another change from the plan, which features stringers for the upper fuselage decking.
This was sheeted on the original, so for greater realism I covered the upper fuselage with very light 1mm balsa sheet. I also reworked
the nose, omitting the foam that Dave used, though this was down to personal building preference rather than anything else.
The model was covered in white esaki tissue, pre shrunk on a frame for all the rather fragile tail surfaces.
All the struts were made from laminations using a centre core of thin plywood with balsa either side, sanded to a streamlined section. 1/32"
ply for the cabines and 1/64" for the interplane struts - no wire was used anywhere in the struts to save weight. The wing rigging is
fishing nylon (painted blue as per the original), hence
functional, whereas the control surface cables at the rear are lycra thread, coloured black with a permanent marker before application.
The model was airbrushed using my favourite Xtracolor "RLM Silver" enamel thinned with dope thinners. You don't need to apply
much to obtain a solid looking finish. All the markings, with the exception of the SMT badges were cut from painted decal sheet and
applied to the silver tissue. I used Daco products decal softener to get them to snuggle down properly. Window frames were also cut from
silver painted decal sheet.
The photos of the finished model show the scale prop I carved to keep the static judges happy - for flying I used one of the white Easy Built
10" props, which works really well. Power is 2 loops of 3/16" rubber and all up weight 97 grams including rubber and noseweight. To put this into
perspective, each wing panel is close to 50 sq. inches.
Three weeks before the 2016 Indoor Nats I drove two hours up to Peterborough, with the model unfinished but flyable, to see if I could trim it out.
It proved surprisingly easy, as it just flew so slowly. Any trim chnges were very gentle, and the model proved very easy to catch if it started heading towards the walls.
It needed a bit of noseweight, some left rudder (glued in place once a suitable turn was achieved) and some down aileron on the left wing.
Here is a video taken by Russ Lister on the day.
Needless to say I drove home extremely happy - definitely worth the journey!
In order to maximise the number of classes I could enter at the 2016 FAC Nats, I wanted a model I could enter in more than one event, with the
proviso of course that I could fit it into my model box. I'd had an idea running round my head for a while that an enlarged version of my
Peanut scale Seamew could go well, but moulding the blown canopies put me off a bit. However, Lindsey Smith then produced a canopy moulding
for the 22" span Frog Senior Series Seamew, and when I enlarged the peanut to 22" span, the tricky bulbous parts were exactly the correct size. I'd
have to bend a windshield from flat sheet, but that didn't look too difficult.
The main structural difference to the peanut model is the use of a cracked rib wing. I left all the fuselage formers in the same positions, but added one or two
extra stringers. Also some soft balsa in-fills for some of the trickier contours. The distinctive radome was carved from soft balsa and hollowed out with a rotary tool.
To strengthen the wing to fuselage
join, I added a box across the fuselage to accept interlocking balsa tongues mounted in the wing centre sections.
The separate removable outer panels are only required because I have to fit it in my model box - normally a model this size would be one piece. It means adding
extra weight, but it can't be helped
Here she is ready for painting - covering is white Esaki.
Finish is my usual Xtracolor enamels which go on gloss, allowing the decals to go on without silvering under the clear film. A final coat of acryic
varnish after decal application kills the gloss and seals everything nicely (after masking the canopies first of course). This view shows the wing slats
quite nicely, and the underwing serials cut from black painted decal sheet. For the roundels, firstly white discs were
masked and painted onto the model, then red discs and blue rings cut from painted decal sheet using an Olfa Compass Cutter were applied over the top.
The finished model weighed 43 grams without rubber, but including the 8" Easybuilt plastic prop. Wing area is 90 sq. inches, so I'm
reasonably happy with that. I'm planning to start with 2 loops of 1/8" rubber and see how it goes.
Update August 2016
A little noseweight was required and the model wanted to fly right, which was fine by me. To keep the right wing up in the turn, 1/16" sq. "Gurney" strips were added under the right wing trailing edge.
I've found you need to launch with the right wing down a little to get it into the turn, especially when fully wound.
Two loops of 1/8" rubber proved to be
the ideal power, and to get extended duration, I increased the length to approx. 3 times the peg to hook distance. To avoid the problem of
the rubber climbing up the diamond prop hook, I fitted a new reverse S hook, which did the trick. With the longer motor I was able to get a thermally assisted 2 minute flight at the
2016 FAC Nationals - my first ever at the event.
Here's the Seamew in action at the Oxford Model Flying Club "Scale Fest 2016" meeting - well under maximum winds, but the open rubber class here was judged on realism, not duration.
Thanks To Monique Lyons for the video.
The plan for this model is now available as a free download here
As the jury was still out on the ability of the Beriev to be a consistent performer, I thought I'd better get a back-up FAC scale entry started
for the 2016 Nats. I've loved Chris Starleaf's 29 inch span Cessna 310 design since the plan was published in FAC news, and it's a proven class winner, so
really it was a very simple choice.
The fuselage was a fun build, with the upper structure built "in the air" above the basic box. I love the way Chris has captured the shape
of the fuselage using just a minimum of sticks. Wings are cracked rib type, with the usual tongues and boxes outboard of the nacelles to allow the outer panels
to be removed for transport.
Chris made his tip tanks out of heat formed plastic foam plates, but I thought I'd do them in stick and tissue using 1/20" balsa, to give the same translucent effect as the
rest of the airframe.
I was pleased with how they came out, but have proved a bit vulnerable to wingtip landings (I now have one or two cracked stringers).
Finish was airbrushed Humbrol gloss yellow enamel over yellow Esaki tissue, with the fin being blue enamel over blue Esaki. All markings are cut from painted decal sheet.
I finished the model the Saturday before I flew out to Boston, so didn't have time to put on all the panel lines and door outlines that I wanted to. This meant that
I took it out to Geneseo completely untrimmed.
Final weight was 54 grams without noseweight or rubber, but including the two scraped Czech 6" plastic props.
Test flights commenced with a loop of 1/16" and a loop of 3/32" in each nacelle, about 2.5 times hook to peg distance and braided. After adding some noseweight and a bit of downthrust,
the model looked quite stable, but was turning a bit sharply left and not climbing away. A length of 1/16" sq under the left wing trailing edge worked a treat in opening up the turn by keeping the left wing up.
On the Saturday of the competion I was delighted to get a 64 second flight on 1500 winds. To get any more duration I think I'll need longer motors, as they felt pretty tight at those winds.
Here is a video taken by Monique Lyons of the Cessna in action at the Oxford Model Flying Club "Scale Fest 2016" meeting.
This is a peanut scale plan by Paul Boyanowski which I decided to build to take out to Geneseo in 2016 - the design is light, and I hoped it would
fly well. It
doesn't have the level of detail I would put in a BMFA peanut, for example no scale rib spacing, but for this model, duration is he main
Structure is mostly 1/20" square with ribs and formers from 1/32" sheet. The rudder and elevators are hinged - a feature not on the original plan, but useful for trimming.
Here is the model covered in Esaki tissue, ready for painting.
My chosen scheme is an aircraft operated by the SOHIO
Oil Company, which has white fuselage and red wings and elevators, so the components have been covered in the appropriate
colored tissue to suit the final airbrushed colour. Tissue preshrunk on a frame was used for all the tail surfaces to avoid warps.
You can see the removable nose plug including the engine cylinders modelled in relief.
Final weight without rubber came out at 15 grams, so heavier than I'd hoped. I blame that caked-on enamel paint finish.
The model had its first hops in a local school hall, and it looks pretty hopeful - a couple of steady circuits were
obtained once the rubber cross section had been upped from a
loop of 3/32" to one of 1/8". I think this will be fine for outdoors. Needless to say I finished it too late for the 2016 FAC Nats, so
it had to wait till 2018 for its competition debut, where I'm happy to report the model flew well, doing about 50 seconds in
dead air - just a shame I never managed to catch a thermal!
Peanut scale Blackburn Ripon
This was yet another attempt at a lightweight peanut for BMFA competition. It's based on the (accurate) outlines of my Dime Scale
Ripon, but the fuselage sections have been improved using extra stringers, and the flying surfaces have scale structure.
To get a scale rib spacing at minimum weight, about two thirds of the ribs are indicated only by sliced upper ribs – only the remaining third have top and
bottom strips. All four ailerons are hinged (half a scale point per separate control surface surface is the reason for this!)
The rudder and elevators are also hinged.
Total weight without noseweight or rubber came out at 12.6 grams, which was really pleasing. The paint finish is my usual Xtracolor enamel,
but this time RAF High Speed Silver rather than RLM Silber. Most markings are cut from painted decal sheet, including the upper wing checks.
For a change I used an Easybuilt 5 inch prop instead of my usual cut down Tern 6 incher.
Initial flights were at the pre-Nats trimming session at Peterborough in 2017 and somewhat to my amazement I seem to have finally managed to design
and build a competitive and very stable peanut, something I've been trying to do since my long-retired Fox Moth.
It needed some noseweight, but flew from the off in nice left hand circuits, and the only real challenge seems to be choosing the correct rubber
for maximum duration. I really thought I’d need a loop of 1/8” but that was too much, so went down to 0.109”, which still got it up to the roof
with 900 winds. So, a final change to 0.100”, which hit the roof after 1200 winds. Maybe 3/32 will be the sweet spot? (about 0.094” to save
you doing the maths). Oh, and it takes off as well, so that gets me an extra 10 seconds.
Now I know it flies, I've added the plan as a download here. I think it would also make a nice model scaled up, for instance 22 inch span would be 1/24 scale.
This was not a model I had planned into my schedule – it’s all Greg West’s fault. He sent me a pdf of the plan, which is a pre-war Comet
design, and I knew I just had to build it. The wingspan is 34 inches, and the structure is incredibly light. It is amazing just how little
wood some US designers were putting in their models compared to the bricks turned out by some UK companies.
I thought this model had the potential
to be a real floater for outdoor flying when the weather is calm. There is more structure in some peanut scale models than this, but what there
is in this design looked to be in the right place. The Warren girder struts would help to keep the wings rigidly aligned, and the main challenge
seemed to be the undercarriage, and how to make it more crash resistant. Greg has built one and successfully flown it -
you will find a video of it in action in the 2010 FAC Nats report.
an additional turbulating 1/16" square wing spar between the main spar and the leading edge. The kit design has a single
3/32 x 3/16" main spar shown on the bottom, which I converted to two 3/32" square spars, one on the top and one on the bottom.
After originally building the wings with the dihedral shown on the plan I later decided to re-cut the joins where the outer panels join
the centre section and put in a touch more dihedral before replacing all the gussets.
The cowl is wrapped with soft 1/16" sheet rather than notepaper, to make it more robust. Also I put in a fuselage-mounted wire
landing gear to run inside the front undercarriage struts, so it would deflect backwards in the event of a heavy landing.
Here is the model covered with white Esaki tissue and ready for painting. The wire undercarriage legs
were sheathed in balsa, and the rear legs, which are
attached rigidly to the balsa fairings next to the wheels, are free to slide into slots in the fuselage as the undercarriage deflects backwards. By a lucky
coincidence of geometry, there is practically no rotation of the rear leg at the wheel fairing end as it slides back into its slot. My balsa wheels are larger than shown on the plan
to make them closer to scale.
Adding the many details shown on the plan was rather satisfying, including the torpedo and its hangers. The torpedo is basically a
rolled 1/32" balsa tube with hollow soft block sections front and rear. The rear block was shaped, then cut in half and hollowed out with a
rotary tool, getting the walls as thin as I dared before gluing the halves back together. The completed item came out at just 3 grams.
Initial flights were made at the pre-Nats trimming session at Peterborough in 2017. I’d not planned to fly the Shark indoors, but in the
light of how well my big Fox Moth had gone, I thought I’d give it a go. It came out a bit heavier than the Fox Moth, at 100 grams without rubber,
but it does have a fair bit more area. The Shark has no movable control surfaces so trimming was done using just gurney strips, rather than add
unsightly trim tabs. I started off with a motor of 2 loops of 3/16” rubber, but soon realised this wasn’t going to be enough, and ended up adding
a loop of 1/8” to the motor. To get it to turn within the confines of the hall, a strip of 1/16” square balsa was added to the left side of the fin
(model was trimmed to circle left). A relatively short length was needed. A bit of noseweight and downthrust was needed to cure a gentle stall,
and then the model would take off OK, but not climb much, and the left wing was keeping very low, leading to an extended taxi on one wheel
after landing. If the model had been equipped with hinged ailerons, I would have dropped the left one and/or raised the right one to cure this,
but on this model it was time for more Gurney strips. By gradually adding approx. 20 mm long strips of 1/16” square balsa under the left wing
trailing edges you could see the left wing dropping slightly less with each flight, and the model climbed a bit higher every time. It took
six additions before I was happy with the flight pattern. What was impressive was how the Gurney strips under the wing had no noticeable effect
on the turning circle – the plane just flew in a more level attitude.
Here is a video of the best trimming flight from the Peterborough session - thanks to Monique Lyons for the footage.
Saab J.29 Tunnan
The discovery of a forgotten stash of still functional 80 mN rated Rapier L1 motors gave me the impetus to finish off Saab Tunnan number 4, as it seemed a shame
not to have a model to put them in. This one is just half an inch bigger span than my very first Tunnan but with the structure unchanged, so 13", as I hoped this would handle slightly more powerful motors than my
old 12.5" span model, which was happiest with 70 mN rated motors.
The decals on this model were made with my new Hewlett Packard colour laser printer, and I was pretty happy with the results. As with the
thermal wax transfer printer I used to use, they need to be put over a white background for the colours to show up, and a protective varnish coat helps to protect
the toner from handling and strengthens the decal.
I managed to get a complete flight out of the model first time out while waiting for the Oxford Port Meadow scale meeting to be cancelled (rain was forcast later).
As often happens with Rapiers, one batch of identically rated L1 motors was distinctly more powerful than the others. With the lower powered batch the model could just about get away
if you let the thrust build up before launching. On the other hand, the higher powered batch lead to some aerobatics. I have marked the boxes accordingly! The model weighs 14.4 grams
without a motor on board.
This is the Airsail 24" span kit of the Piper Tomahawk which has been in my stash for ages, but I was inspired to build
it after watching Mike Mulholland's build of the Airsail Pilatus PC-9 on the Hippocketaeronautics forum. Like Mike, I tried to get some weight out of the design,
and I was helped in this aim by Avetek in New Zealand (who took over the old Airsail designs) sending me a new laser cut set of lightweight formers - far superior
to the die-crunched offerings in the original kit.
The plan was to trim the model unpainted so I could feed back to Avetek whether it flew OK and here she is ready to go, covered in white Esaki tissue.
Upper and lower nose cowls are supplied as vac-form mouldings, but I added
extra plastic card side pieces between them to remove the unsightly steps. With two loops of 1/8" rubber on board,
the all-up weight was 48 grams, but I didn't need any nose weight. New laser cut kits should have thinner guage canopies and styrene mouldings which
will save a few grams.
I'm happy to report it did fly well and seemed pretty
stable, with a Gurney strip under the left wing to keep it up in the left hand turn.
At the time of writing, I've not had the chance to fly it with all the enamel paint airbrushed on, so fingers crossed
the centre of gravity hasn't moved too much. There were times when I regretted choosing this rather ambitious colour scheme, as the tail ribbons took ages
to do. Each multicolour ribbon is a printed decal placed over the white painted fin. The hardest bits to do were the pieces that
wrapped round the rear fuselage, as the shapes had to be developed by trial and error, then individual pieces of printed coloured decal
were placed one at a time on the model. That was 11 pieces per side which had to match up to the pieces on the fin. In real life it looks
a bit scruffier than in the photos, but viewed from a few feet away it looks fairly convincing.
Pistachio Scale Mr Mulligan
I was pretty sure it would end in tears, but even so I had another attempt at building a Pistachio scale model that might actually fly. My
two previous attempts have been failures, so this time I chose a high wing cabin monoplane in the hope it would be easier to trim. Needless to
say it wasn't!
Although I was pleased with the way the model looked, it ended up far too heavy, at 6.3 grams (though that did include the motor) and never showed the slightest inclination to fly.
Cutting the prop diameter down made no difference. either. I think I'll use it as a Christmas tree ornament!
Keil Kraft Achilles
I built this as a bit of light relief from the serious scale stuff, plus this early version is eligible for the Flying Aces Club small cabin
duration class. The original Achilles was designed by Louis B. Heath in 1939, and has quite a few differences to the 1950 Albert E. Hatfull redesign.
The most obvious one is that the dihedral break on the first model is one bay nearer the fuselage, but there are many more little changes as well.
I carved an 8" balsa prop for it, which I rather enjoyed - it had been a while since I did one. Weight without rubber was 33 grams (wingspan 24").
As expected, the model was very easy to trim and I had high hopes that it would be competitive in its class at the Flying Aces Nationals.
Unfortunately, as documented elsewhere, I managed to lose it on a trimming flight before the day of the competition. So - time
to build another one. I'm more cross about losing the prop than anything else!