HPA

Big thanks to George for getting this forum up and running here. Great effort!

This is my latest indoor scale project, started when I came back from the IIFI feeling inspired to start on a new Indoor Nats model. It'll be 25" inch span,1/16 scale for rubber.
It's a Short S.42 which was very much based on the Bleriot XI, the main difference being it had a beefier undercarriage that dispensed with the Bleriot sprung 'bedstead' system. It was flown in the early days of the RNAS by the legendary Charles Rumney Sansam.
Some pics and two 3-views can be found here: https://flyingmachines.ru/Site2/Crafts/Craft28639.htm

Mine is based on the drawing from the Putnam book:'Short Aircraft since 1909'by C. Barnes.
(The other drawing on that webpage is from the Peter Lewis Putnam book:'British Aircraft 1809-1914' but to my eyes it's not quite as accurate as the other one.)
I only have the makings of a fuselage so far, with quite a lot of rigging done in the open section. I'll be using the same aerofoil as on my Bleriot, as plotted for me by Toon Verbruggen.

Great subject Pete I shall look forward to following this one.

Hopefully this will some of the wonderful flying characteristics of your Bleriot, the fuselage is looking pretty good already . Interesting that the Short appears to be a larger aircraft than the Bleriot given the different scales between your two models. I had always assumed it was more of a copy but clearly not

Sorry, should've said 1/14 scale, not 1/16. Span of original aircraft was 29' 3".

I now have wings! I used the same Toon Verbruggan aerofoil as on my Bleriot, which is quite drastically undecambered and a bit of a faff to make as none of the spars can be laid flat on the board. Done now though, so hopefully the effort will be worth it. Tips were laminated round a form.

The tailplane on this aircraft was also undercambered. I'm not sure how closely to replicate this on my model. I suspect such lifting tailplanes are a bit of a pain when it comes to trimming so am tempted to tone it down a bit, or maybe even flatten it completely. Does anyone have thoughts or experience with this?

Quote from: Pete FardellThe tailplane on this aircraft was also undercambered. I'm not sure how closely to replicate this on my model. I suspect such lifting tailplanes are a bit of a pain when it comes to trimming...

I built the Mooney peanut one with a reflex tail as per the plan, but didn't get enough intact landings out of it before I gave up repairing it to be able to tell whether or not I should have gone for a flat tail. However the flights it did make were quite... swoopy which suggests to me there was an up elevator effect giving a climb / soft stall cycle. 

I may be able to tell you more when I finally finish my "big" Chiribiri, see pic. :)

Why not use the same section as you did on the Bleriot. You know it worked!
Ron

Hi Pete,

Very nice, clean, accurate woodwork! I always enjoy your builds.

Stephen.

Quote from: cvasec on Jan 11, 2026, 12:41 PMWhy not use the same section as you did on the Bleriot. You know it worked!
Ron

My thoughts too. The real Channel Bleriot had a more or less flat tailplane though, so although mine is of thinner section I didn't have to worry so much about it looking unscale. I think it'd be more obvious on this one.
 I think I might do it flat and put 'cheat ribs' at each end to sort of suggest a bit of undercamber.

Quote from: TheLurker on Jan 11, 2026, 10:57 AM

Quote from: Pete FardellThe tailplane on this aircraft was also undercambered. I'm not sure how closely to replicate this on my model. I suspect such lifting tailplanes are a bit of a pain when it comes to trimming...

I built the Mooney peanut one with a reflex tail as per the plan, but didn't get enough intact landings out of it before I gave up repairing it to be able to tell whether or not I should have gone for a flat tail. However the flights it did make were quite... swoopy which suggests to me there was an up elevator effect giving a climb / soft stall cycle. 

I may be able to tell you more when I finally finish my "big" Chiribiri, see pic. :)

It's a masterpiece! Very clean job!! Bravo!

QuoteWhy not use the same section as you did on the Bleriot. You know it worked!
Ron

Sounds like a good plan. My co2 Bleriot had a lifting tail but it has a modest undercamber rather than the deep undercamber you can see in the photo's. I think you are right to compromise on the section and you know the Bleriot one works

Thanks for the thoughts on the lifting tail. I really both Lurk's Chiribiri one and the Brainwood Bleriot's. However, I've now built mine with a flat underside and just a bit of camber on the top. Hopefully it won't misbehave.
I've also made the tailskid and rudder. I'm slightly worried the rudder is a bit small, but it is to scale dimensions. It would be a very quick job to make a larger one though, so I'll leave it for now.

I've made the wheels now too using a patent  "lolly stick" method which worked out rather well. The stick was removed after the first round of spokes were threaded on, then I cut more grooves in the rim and added another lot of spikes to fill in the gaps. Just two lengths of thread were used for each wheel.

Tyres are just rings of 1/32 balsa stuck together and glued onto the rims.
They still need painting of course, but here they are in situ and also a mock-up shot of all the bits now made. Dummy engine next.

I didn't know Sir Michael Caine built model aeroplanes.  Live and learn, live and learn.

Oooh that's looking very evocative already. Wheels look great too
 

I've gnow made a Gnome. I might still decide to dirty it up a bit.
For winding, the whole thing comes off but the front part also unplugs to enable static prop fitting and thrust adjustments. The cylinders are plastic tubes wrapped in paper, but I hid a bit of lead in each one as they're a good place to hide some of the inevitable gnose-weight.

More progress...
Covering went well, by my standards. Tissue is, I think, almost the last of my white Esaki. I'd already run out but must've got two more sheets from somewhere. It was possibly from the stock of the late Ralph Sparrow. (Thanks, Ralph, if it was!)
Anyway, there were fewer wrinkles than usual especially after being steamed twice. Two coats of thinned non-shrinking dope applied.

It's not all been plain sailing though. I noticed the aircraft was standing too tall, and the reason was that the u/c legs weren't splayed enough. Some fairly drastic surgery rectified this, and I'm happier now (last pic). The resulting wider track will maybe help with its ground handling too?

Colour spraying also went okay, although my airbrush keeps losing pressure so it was all a bit stop-start. Paint is the good old Xtracolor "RFC Doped Natural Fabric" from Hannants. Rib tapes are tissue strips glued on afterwards. A light spray of clear satin acrylic varnish took the shine off.
Nearly ready for rigging now.

That is looking very nice, Pete!

Same as wot George wrote

Stephen.

Yep as above... Looking very lovely

Beautiful Pete!

Hi Pete

What tissue did you use for the rib tapes? More Esaki?  Did you colour it?

Quote from: Jmk89 on Feb 13, 2026, 09:05 AMHi Pete

What tissue did you use for the rib tapes? More Esaki?  Did you colour it?

It was grey tissue from VMC but before cutting the strips I coloured it with a brown colouring pencil. I'm guessing on the colour really- the tapes show up on most of the photos of the real aircraft but are not all that dark.

Thanks for the info, Pete

Well I'm calling this one done. Rigging is thread, and the pilot is carved blue foam.
Weight as seen is 84g. 26g of this is the prop and dummy engine/noseblock assembly, with a lot of lead incorporated. It'll need a bit more yet I fear, but maybe it'll still be under 100g at flying weight. My Bleriot balances at about 37% chord, so I'm hoping this will utilise a similarly rearward CG.
Some pics..

And I couldn't resist doing a few comparison with the real McCoy shots...

Great model Pete and I love the comparison shots. That's looking pretty good, best of luck with the trimming. I doubt you've tried a test glide yet in our soggy windy conditions ?

Lovely.

Wonderful Pete. I really enjoy your pioneer-era builds - the Bleriot in flight always makes me inexplicably happy. This looks like it will be another good one.

Cheers,

Mike

Loads of period charm there Pete. Good luck with the trimming.

John

Really great, certainly looks the part.

Thanks all for the nice comments.
I made a start trimming it today, at the Manchester Velodrome. I did actually set out  to try it in my field last week, but when the first test glide went three feet forwards from my hand, and then three feet backwards back INTO my hand I decided it was maybe too windy.

No wind at the Velodrome though...
It was as a bit stally at first but this is how it went after even more noseweight was added. (It even qualified in the competition!)

Ooh, they were very, very promising flights indeed. Can't wait to see it in action come April.

Lovely!

That has turned out very well! 

I wonder whether it is a little over scale speed (I'm comparing it in my mind with the film I've seen of the Shuttleworth's Bleriot and Blackburn).  But that's really nit-picky.

I love your renditions of the early planes.
Ron

Superb Pete. Who needs Keil Kraft grass, looks the Bleriot may have a rival

That's a lovely model and seems to fly as well as it looks! It really evokes the slow flight of these pioneering machines.

Very promising, are you sure that's not a power stall?

I feel Dave is right here. It looks like it is flying very close to the stall and may cause issues with more power if needed. It looks lovely flying though.

John

Well, the Short was not a great success at the indoor Nats, so I took the opportunity of an almost windless morning today to try a bit of outdoor trimming. Yesterday I firmed up the prop assembly/noseblock which was all a bit wobbly, including redrilling the nose plug to take a better, thicker prop shaft and hook. I did a few motor runs to make sure nothing was bunching or seizing up and all seemed okay.
First flight in the field, with about 400 turns (and which I didn't video) was quite promising; a long straight powered glide and no alarms. More turns and just a bit of left rudder and it still looked sort of okay-ish, but not really quite there. You can see a stall at the end of the second flight. The hard landing/crash in the last flight I filmed resulted in undercarriage damage and an end to the day's proceedings (damage not too bad though, and now repaired). What next I wonder?

Richard Crossley's thought, having watched the videos, is that perhaps I don't have enough incidence. This would explain it pitching in after the stall, and also why it flies much faster than my Bleriot despite having the same aerofoil and a very similar layout. I can't easily move the wing, but can certainly add up elevator to the tailplane.
(It's a pity there's no long grass left near me though.)

I was thinking the same - a bit fast compared to your similar-planform model/s, and why the apparently negligible capability for stall recovery. I suppose for wings with such highly undercambered aerofoils it must be hard to estimate the 'decalage'. You can see it geometrically but that's not how the airflow sees it.

BTW Pete, is Breighton airfield Bray-ton, as in donkey, or Bry-ton, as in daytripper?

Stephen. p.s.Or even Bree-ton, as in cheese?

Quote from: Prosper on Aug 24, 2026, 01:54 PMPete, is Breighton airfield Bray-ton, as in donkey, or Bry-ton, as in daytripper?

Stephen. p.s.Or even Bree-ton, as in cheese?

Bray-ton I believe.

Ta.

Nice and calm yesterday so I gave the Short mono another go. As recommended by Mr Crossley I'd put a lot of negative incidence on the tailplane (up elevator)to try and keep the wing at a higher angle of attack. It was instantly better; slower and with no nasty sudden dives. It wasn't really climbing though, so I swapped in my Bleriot motor of 5 braided loops (10 strands) of 1/8, in place of the 4 loops I had before. It still doesn't get much height but if I can stop the motor bunching at the rear peg I think I can probably get more out of it. The trouble is it's a smaller model than the Bleriot, but not much lighter so evidently needs as much rubber in an even smaller space. Perhaps though I can rebraid to be even shorter, or else lose a few inches and hope it's still enough. Anyway, here are 3 short flights from yesterday. The drop in at the end of flight two is, I think, the result of the aforementioned bunching. Poor launch on that flight too.

Looking much better Pete. Without the upset of the outdoor air that's looking much like it will do it indoors. I think I would try re-braiding the motor shorter, you'll loose a few turns doing that but possibly better than a shorter motor ?

Applying the JOD principle that scale models are over-rubbered and under-wound, it might be best to reduce the rubber but wind it up some more.

 The upside is that you will then be accessing the high torque of the motor when it gets to 90% of the available turns, and, with suitable thrust adjustments, that should encourage the climb. The downside is that winding up to that level does lead to tired motors, so they have to be changed more often.

Quote from: Jmk89 on Sep 30, 2026, 04:38 AMApplying the JOD principle that scale models are over-rubbered and under-wound, it might be best to reduce the rubber but wind it up some more.

Thank you; I have considered this route and to some extent it's what I'm trying to do already. The previous motor (8 strands of 1/8 instead of 10) may still have made it "over-rubbered" but it wasn't under-wound. That's to say, with both this model and the Bleriot I do tend to wind to near max as my quite regularly broken strands attest.
What I haven't yet tried with this one though is to go with even less rubber, say just 6 or 7 strands, before piling on the turns. The trouble is that with all the nose-weight the model isn't very light so I'm doubtful that I can reduce the rubber that much and still get it to climb at all. Might be worth a go though.

Surely though if you are winding a 10 x 1/8 motor to full turns or presumably 80% of breaking turns then a smaller motor even if wound to breaking turns will not produce as much power and therefore not climb as much ? I wondered if you needed more power ...11 strands ?

Quote from: Squirrelnet on Sep 30, 2026, 02:34 PMSurely though if you are winding a 10 x 1/8 motor to full turns or presumably 80% of breaking turns then a smaller motor even if wound to breaking turns will not produce as much power and therefore not climb as much ? I wondered if you needed more power ...11 strands ?

I think maybe you're right, but am a bit loathe to try and cram even more rubber in and if I can stop the 10 x 1/8 motor from bunching then it might yet get a bit more height before it starts descending. It climbed out a bit on the second flight in my video but couldn't sustain it.
Everything really is the same as on my Bleriot, which occasionally gets quite high but usually doesn't.

Of course, there is another side of the equation that can be looked at. That is whether the prop is correctly dimensioned for the motor.

In the current situation, where you don't seem to be getting quite enough climb from the high torque beginning of the motor run, I suppose there are three prop variables that can be considered:

• reduce the weight of the prop blades  - I've had very little luck are doing this.
• reduce the pitch of the prop - this is the basis of the variable pitch mechanisms used in rubber duration. Finer pitch is used at the beginning to help the climb and during the cruise section, the pitch is increased so that, even though the prop is turning relatively slowly, it is still taking a decent "bite" out of the air with each revolution.
• reduce the blade area - in effect, this makes the proper easier for the motor to turn. It also means that you can make adjustments to an existing prop rather than having to make a new one. You can either slim the prop down by thinning it at both leading edge and trailing edge, or cut an equal amount of each tip or do a combination of both. It will rather depend on how brave you are.

Some flyers that I have met actually have a test prop system which they use when first trimming the model to determine the best prop geometry before making the prop they actually want to use. In essence, it is a hub into which different sets of  blades (with differing diameters and chords) can be inserted and which also allows the pitch of the blades to be adjusted . After a few years, the number of sets of blades can become large enough to allow a pretty good estimate of what the "best" performing prop will be and that prop can then be carved.

One other thought I had is that the lighter motor, if more than 50% of the motor is behind the CG, will bring the CG forward and some of the nose weight may need to be removed to get the CG back to the correct position. You might find that just that reduction in overall weight is sufficient to enable the model to climb better.

As always, there are plenty of things that can be tried to get the desired result!

Quote from: Squirrelnet on Sep 30, 2026, 02:34 PMSurely though if you are winding a 10 x 1/8 motor to full turns or presumably 80% of breaking turns then a smaller motor even if wound to breaking turns will not produce as much power and therefore not climb as much ? I wondered if you needed more power ...11 strands ?

If you look at the turns/torque curves (eg on page 24 of the JOD collection soon too be available in the Plans Gallery), the high torque part of the curve doesn't come until at least 90% of the break turns are applied. At 80% you are just in the early part of the cruise part of the torque curve.  Duration models are always wound to 90% or more - that's why you only get 2 or 3 competition flights from a motor.

I think it was looking at the reluctance of scale modellers to wind into the high torque part of the curve that led JOD to say that the motors were under-wound.

Jeremy, thanks for all those thoughts. Plenty to consider for me there.
As far as winding to 90% goes, I suspect scale modellers' reluctance to do so stems from the fact that damage resulting from a burst motor in a scale model is much more of a hassle to repair than it is with duration models. And winding tubes don't eliminate the risk of leaving the dreaded angry ball of rubber bunched up at the back.