Topic: Airsail Auster 1/4 Scale

Hi,

I've built quite a few models, from kit and plan, over the years but never done a build diary as these projects normally take me a couple of years and I suspect everyone would get bored over that duration.  However, I now have an enforced period of many weeks at home, and have to have some rehabilitation therapy for my hands and arms.  Would you believe it that the hospital considered a model aircraft kit build perfect therapy?  You really couldn't make it up and the wife couldn't disagree!  So, I hope to be airborne for our club Warbirds day in mid March.

Anyone interested in a build diary for this kit?  2.8m span, 9 kg, to have a DLE 30 petrol.

I think I've attached a couple of <50kb images - but the preview doesn't show them.....

Andy

Anyone interested in a build diary for this kit?  2.8m span, 9 kg, to have a DLE 30 petrol.

Andy,

of course we do

I've heard mixed comments about this kit, so hear's hoping you got a good one


Mark

I'll certainly be watching! 

A number of forumites have built from Airsail kits in the past, with mixed views. It'll be good to see this one go together. Any build is worth a look imho, as we all learn something from each other.

Always interested in a build.

Hi Mark,

I was wary about the Airsail Auster kit quality - mainly because I built the RAF variant of the Chipmunk a few years ago.  The wood quality was variable, some of the ply was horrible, and I used some of the parts as patterns to cut new ones from better wood.  But the included hardware was very good, and the building plans were also excellent.  I put an OS52FS in it, and it's now one of my favourite models. The ABS cowl is now at the end of its life and I'll shortly get a Carbon Copy GRP cowl and fit that.  The Chippie is a beautiful flyer - summer Sunday afternoon stuff.  Very scale, no nasty habits, and it flies perfectly on the OS - just watch out for nose-overs on landing.

So, I knew what I might be getting into with the Auster kit - just on a grander scale.  My LMS had one in, so I was able to unpack it and check out the wood and parts.  It all seems fine, and having had it in the workshop for a few days the hardware is beyond belief - very, very comprehensive.  I've no complaints to date - other than that the build manual is a bit sketchy.  But you do get 7 sheets of full size plans, so anyone with some experience should be able to work it out.

The timber quality is fine so far - and the cutting is good.  Not as good as a laser cut Sig or Glen's, but perfectly adequate.

Not sure if Airsail really make kits now - my LMS says he can get them, but they don't seem to feature on the Airsail website.

So, on with the diary!  Watch this space!

Andy

Seen one of these flying today (Barkston Fly-in and at Langar last November) great flying model in my opinon. Can I ask were you got the model from and its price as I rather fancy one myself?

Greyfly

If you can't get hold of the Airsail one I can recommend the D B Sport & Scale version. Slightly smaller at just under 90 inch span, the quality of the wood in the kit and the lazer cutting is truly excellent.

A friend of mine, recently returned to the hobby after a 14 year break, has just built the D B Auster. He said it went together like a dream. He ought to know, he built the same kit before quitting the hobby last time, and he says the quality of the new kit is worlds apart from the "old" one.

Hi Greyfly,

I bought mine in my LMS, Whitchurch Models, Whitchurch, Salop.  The box price was £270, but Martin's usually up for a deal!

Andy.

OK, here we go - my first Build Diary.

Adhesives are ordinary woodworking PVA for most joints - used it a lot and it's fine, Z-Poxy where instructed, and a bit of cyano where necessary.

There are numerous sub-assemblies, but it all starts with the engine box and F1.  There are 2 No. 6mm ply base plates which carry the u/cart (pre-formed massive piano wire far stronger than my bender would have coped with).  F1 is fabricated, mounted on the base plate, with locators for the u/cart.



The firewall is then epoxied in place, with supporting ply panels, and other 5mm balsa sheeting to box the engine mount out.



My 2t bottle jack is very handy as a weight whilst epoxy sets off!

A bit more cutting, shutting and glueing....you can never have too many clamps - and I never seem to have enough.....



Finally, the completed engine box looks like this...



Now it's on to the cabin assembly - loads of bracing struts to get lined up so that the wings go on straight and level....

Anyone interested in a build diary for this kit?  2.8m span, 9 kg, to have a DLE 30 petrol.

ooooooooo yes please, they are my sort of vital stats....

Build thread for sure

Buzz2 on here has built one. I've flown it a few times and it is truly superb, looks great too

Ian.

I'v had one of these for about 3 yrs now...

The build has sort of stalled...for about the last 30 months.....
Iv done 80% of fus, 90%| of one wing and 60% of t'other   -  the manual is very vague in a few areas - particularly where it states you have to break some fus stringers....

Get on with it...you might just inspireme to crack on with it.

Jez

Hi all,

I didn't expect to be providing Jez with inspiration to finish his build - but if it helps!

The manual is certainly vague - from page 1 indeed - but my mantra has always been never to make irreversible decisions - or difficult-to-reverse glued joints - late at night   . Put it down, turn the lights off, have a malt (Ardbeg for preference), go to bed.  Next day all will be clear.  Invariably.

Glad to hear from Ian that it's a good flyer.  I wouldn't normally have gone for a high winger these days, but I've just had spinal surgery, which didn't quite go according to plan, and has left my finger actions a bit sluggish - hopefully they should recover over the next few months.  I'm still OK to fly, but I decided that a model that's a bit less committing than most of mine - maybe except the old faithful Wot4 - would be prudent.  So a large,  petrol, lightly loaded high winger should be nice and floaty and give my thumbs a bit of reaction time.

Anyway, today's installment:



The cabin sides are 1/8 ply, with a 1/4 balsa doubler on the inside.  However, the doubler needs cutting to clear the u/cart and lower wing struct mounting bracket.  Whilst there's a detail on the plan, the detail didn't quite work for me, and the photo shows a trial fit of the resultant doubler.  The doubler needs to glue up snugly against F1 to get to strength to cope with my (in)famous arrivals.



As I said previously, you can never have enough clamps.

Works stops for tonight now as I'm out of clamps.  Must get some more.  Anyone know of a good online source of cheapo clamps? These are the root ribs that form the wing attachment points on top of the cabin, the cutouts take the bracing tubes.

Night all.

Andy

second picture looks like an attack of the scutters....

Not sure what an attack of the scutters is..............

Anyway, I was musing on the cabin side alignment, and in particular the size of the ply cabin sides this afternoon, when my good friend Tom rang to say he'd seen the diary, and that this was the only kit he'd ever binned and burned!  But not to let that put me off.  But he did say that was a few years ago, and it was all to do with missing bits and problems with wing incidence.  He also said he'd seen a few good examples flying too - so that's re-assuring!

Which was quite timely, as the cabin sides are linked to the root ribs by ply strips, and if I followed the plan then the ply cabin side was slightly too tall at the rear edge (but OK at the front), and hence if I lined up the bottom edge of the ply side with the base of the cabin on the plan, the top edge was too high by about 5mm.    Not wanting to get the wing incidence wrong, particularly after Tom's advice, I set the cabin side lower edge to the plan location, then cut the top edge to match the plan. That meant I could cut the ply strips - which form the window frames, to match those on the plan, and then everything would be as plan. 

Then came the next challenge. 


The instructions tell you to temporarily glue some scrap balsa to the outside surface of the cabin sides to hold the components together until the steel struts are epoxied to the inner face.  That's all well and good, but the outer face is in contact with the plan - so rather than trying to assemble the cabin side components spaced above the plan to be able to add these temporary glue straps, I put even more temporary scraps on the inner face.  The arrows in the next pic show what I did.  I will then add the temporary straps to the outside face as per the instructions, and the temporary temporary ones can be removed.  No chance therefore of some misalignments.



You can also see that I made sure that both cabin sides are aligned with each other - I used bolts through the cabin inner struts mounting holes to make sure. 

Tom will confirm that most of my models fly straight and level (the ones that didn't went home in bin bags), partly because he's maidened a few of them, and partly because I measure, measure, and then for good measure, measure again.  And, if I'm not happy, sleep on it (see the above).  So, I take a lot of trouble to get alignments, washouts and incidences as correct as I can, and at least symmetrical, and it works for me.

When the glue dries, I'll fit these to the engine box........(and take off the temporary temporary straps....)

Andy

I'll be interested to watch this.  I have a part completed one that I haven't touched for about 4 years.  It's not an easy build but that's probably my poor building skills talking.

Geoff

sorry to confuse Andy, they are droids from the Red Dwarf series... See here

http://www.google.co.uk/images?hl=en&safe=off&biw=1259&bih=591&tbs=isch%3A1&sa=1&q=scutters+red+dwarf&aq=f&aqi=&aql=&oq=&gs_rfai=

Hi all, today's instalment...

Sorry Stuey, I knew that the scutters meant something to me, but maybe I remember Holly better!

Interesting challenges today.  It was critical works today - maybe the most critical on the whole build, as it was time to glue up the cabin sides to the main box that carries the engine and the u/cart.  Since the cabin sides also provide the wing attachment points, any misalignment here means that the incidences will be wrong.

First challenge was that the rear third of the main box was missing - not from the kit, but not yet attached.  The instructions say nothing about this, and the photos are not the best (hopefully anyone else building this kit will find mine slightly more useful).  Anyway, closer perusal of a grainy photo showed that this part of the cabin floor should be attached by now, so in it went.  However, it was 250 mm wide, but the model is 244 mm wide.  So, is this an allowance for chamfering at some point - yet to be identified - or simply a part cut from stock?  After walking off for a coffee  I trimmed it down and glued it in place - the arrow shows the offending part:



Incidentally, does anyone know why I can only post 2 No. 50kb display type pics per post?  The editing page says I can post up to 20, max 10,000kb?

I had to tidy up some of the woodwork to give me strong joints when I glued the cabin sides in, and eventually I could no longer delay the inevitable, so glued the sides in place.

That left the wing roots flapping about in the breeze as the cabin sides are quite thin, so the instructions require two balsa temporary formers to be built and attached to the cabin sides, so that the root ribs can be pulled in to the correct alignment.  There's a full size pattern for the formers on the plan, and tacked these to the inside of the cabin, just below the window bottom edge, as per the plan.



After a lot of measuring, checking and checking again the wing root alignment, I could find nothing wrong, so took a deep breath and tacked the root ribs to the temporary formers with thin cyano and kicker.   

Next it's time for some metalwork - the cabin bracing struts, wing attachment points etc.   Watch this space.

Andy

Andy,
Following your build with great interest.
I too have fought my way around shortcomings in the materials and instructions. One question to you before you install the metalwork. Have you considered how you are going to access the Rx, batteries, servos, control runs, fuel tank, etc. once you have covered the model and installed the glazing?
The plans/instruction book are silent on this. The metalwork as per the plan prevents the addition of scale-like doors in the fuselage sides (or have I missed something on mine?).  I resorted to making several access panels in the underside of the fuselage.
Looking forward to the rest of your build,
Bill   

Hi there
If you get stuck I might be able to help ... Brian Borland from Airsail. I've skimmed through the posts ...interesting reading. You seem to be heading in the right direction so far. Re the batteries and RX access ..on the box art model which is still airworthy, I have a hatch on the underside beneath the front seat positions , not scale I know but it's not seen and not obtrusive anyway. Otherwise, I kept the cockpit free of Radio gear with the exception of the extension leads for the aileron and flap servos. If you install these early you can hide them more easily among the tubing which is in abundance on the full size. I also made the side windows removeable along with the rear top canopy section...used Mick Reeves small screws to fasten. Keep up the good work. Brian B 

Hi again

Re the scale side doors ...yes I know the wire work doesn't allow for this to be easily achieved. The model was originally as conceived as a "Sport Scale" model. I know a couple of modellers have altered the metal work around the door area to in include working items.

Of course you needn't stop there either as  part of the side windows hinge upwards and lock into clips on the lower wing surface to allow unobstructed vision for the pilot and observer.

I had ideas of producing a scale U/C unit, complete with shock units but other ideas got in the way.

I read an article recently in a UK mag written by a qualified Private Pilot. He experienced the AOP9 as part of an article subsequently published and as I recall he didn't find it all plain sailing. In particular he had several shots at landing ..it almost bit him once ..and his mentor had to rescue the situation. Our model prefers a power on landing as opposed to a glide approach ...much like the full size. 3 points are not always achieved ...or desireable.

Of further interest, you should know that this model really came about because of Ron Moulton, as did the .40 size version. Ron designed a Free Flight Scale model version released as a plan in Aeromodeller and one of the previous co-owners of Airsail was a great Auster/Ron Moulton fan. Sadly neither identities are with us now.

Cheers ... Brian B

Brian welcome to the forum, always good to see a manufacturer who's able to give help and advice on their products 

Steve

I love this plane I built the smaller on some years ago and wish I hadn't sold it now... they need a lot of rudder in the turns though because of the short moment and the huge wings... but its a gorgeous plane.

Watching with Interest  and jealousy. 

Wayne

Hi all,

Sorry, been indisposed for a few days so no posts, but some build progress - I'll post the photos tomorrow.

Hi Brian - I wondered if anyone from Airsail was watching!  I'll be very happy to have your comments as I progress.

The wirework is done - a bit tricky.  The 8swg wires brace the cabin sides, and are epoxied into slots in the balsa doublers glued to the ply cabin sides (and messy).  Four wires run down the cabin sides, and meet in the middle of the fuse, at wing level.  These are soldered together with brass tube joiners, and then wired together and the wire binding soldered.

There are then 2 more braces which cross the fuse at 90 degrees - or should be.  The manual says that these might need a bit of manipulating.  There was only one in my kit - fortunately I had some 8swg wire in stock (on a Sunday afternoon) so I made my own with my wire bender after a few trials, and since the fit was better than the one that was supplied, I made another to replace that one. 

Brian - this photo is the cabin hardware pack as I unpacked it - there's only one of the 90 degree braces! 



The manual is very specific in that the root ribs must not be distorted by tension in these wires, so this took a bit of time to get as correct as I could make them.  The root ribs are parallel and look square, etc, so I think all's well.

The issue of radio, tank and cabling had crossed my mind, but given the implied dire warnings in the build manual about the wire bracings it never occurred to me to modify these to help with the radio gear and tankage.  Even if it had I'd have put airworthiness above aesthetics and left the metalwork as the designers intended.

I'll have a look at installing some dummy tubes (drinking straws) to carry the servo leads inside the cabin, and see what I can do about hiding the radio gear below the cabin floor - or the seats.  Something to think about so thanks for the heads up Brian - much appreciated.

OK, up to date photos tomorrow!

Andy

New photos as promised.

Here's the cat's cradle of bracing struts.  Soldering needs some cleanup.



There's also a forward-orientated diagonal bracing tube - which you can just see in the photo above - but it's clearer below - I've some cleaning up of temporary glued straps (which hold the cabin side components together during assembly) yet to do.  My work's not that messy!

Now its on to the cowl - all built up - with an ABS(?) front face panel.



It starts with laminating up the ply reinforcing rings which support the ABS front panel. 



Now it gets tricky as the manual and plan's not too clear here.     The cowl has to lift off the front of the fuse, the rear former of the cowl is shown held with a couple of bulldog clips to it's neighbouring fuse former, and I've cut the required slot so it can lift off over the diagonal brace. Next to my grubby pencil there are 2 No. 9.5mm sq rails, which are to connect this cowl former to the back of the ABS support ring - but there's no plan view in the drawings so I'm not sure what angle these run at - I suspect they run along the outside edge of the cowl though - which means some tricky joint orientations to get right.  You can see me glueing up 9.5mm thick sheet to form the outer cowl sides, and just behind the ABS support ring I've propped up the 6.5mm thick balsa doubler panel.  Not 100% sure I know how these are to align and relate to the balsa floor of the cowl......so it's time for tea (and maybe cake)

Definitely not a novice build this one - but that wouldn't be any fun, would it?

Back when I've sussed it.

 

The Cowling - is all built up - and because it's tapered, both top to bottom, and front to rear, the butt joints are tricky.   

Plus, and please tell me I'm wrong Brian, the wood in the kit you need for the cowl floor (C1 in the photos), and the cowl side doublers (C4) is a tad undersize.



The left hand arrows show that the cowl base is about 3 to 5mm narrower on each side than the ply base at the firewall, but the cowl cheeks have to cover the cowl to fuse joint - so surely the cowl base has to be the same width? After last night's tea and cake, I decided to add a bit of width to the cowl floor (C1) so that the cowl cheeks would fit as I think the designer intended.

However, remember the 9.5mm sq cowl rails?  These connect the rear cowl former to the ABS front moulding support, and as built so far sit directly on top of the flat ply plate that will form the top of the tank bay.  But, the outer edge of the ply plate and the 9.5mm sq rail are just about co-incident as built, leaving no room for the 9.5mm thick cowl cheeks to site underneath the rails. The cowl cheeks as supplied (in 3 bits) are just tall enough to fit from the u/side surface of the cowl floor, to the u/side of the cowl rails - so they have to fit underneath the rails, not alongside.  But they can't do that because the rails sit on top of  the ply tank roof plate...............

In the end I cut back the ply plate just enough to be able to let the cowl cheeks slide underneath the rails - see the rhs set of arrows in the above photo.  If I'd cut a slot in the cowl cheeks and left the ply plate as supplied, when I took the cowling off there would be an odd slot in the cowling - and finishing the edge of the ply plate would be unsightly - and it would look odd too as there would always be a ply edge showing under the cowl rails.  That's definitely not scale.

The cowl cheeks have a 6.5mm balsa doubler - and whilst these look square, they're not - because of all the cowling tapers.  After a bit of cussing thinking that the fit was horrible, I twigged this and offered the correct doubler in the correct orientation - and they almost fitted - just not quite tall enough to allow for a chamfer top and bottom to suit the cowl rail u/side and the top plane of the cowl floor.  My dad used to make furniture, and a joint was never good enough for him unless it fitted - fitting where it touched, rightly, isn't good enough.  Had the doublers been 5mm taller they'd have been OK to allow for the chamfers, so I added a bit to them from my stockpile of balsa.  A few minutes with a mini-plane and a sandling block, and they fit perfectly. My dad would let me off that.



I've temporarily dry-fitted the cowl cheeks that the doubler fits up to to get them co-planar - again - it's got to be a good fit.  Cowls get a battering (well, mine do) from vibration and handling, so fitting a poor joint with glue and hoping for the best is not good enough......

The cowling construction is decidedly tricky - anyone else done one?  Hopefully, if anyone's going to do one, my notes may help.

No criticism of Airsail intended or implied here (other than for undersizing the cheek doublers maybe) - the cowl geometry is complex and to have supplied timber to be of the "throw it together and run around with the cyano" dimensional accuracy would be unrealistic in a non laser-cut kit.  The build instructions say that experience is required to build the model - and they are right.  The wood selection is good, the supplied hardware is comprehensive (so far!) and I'm enjoying the mental challenge of working out what Airsail want you to build. 

So, onward and upward............

Andy

and breathe................

OK, so I'm happy with the cowling structure, it's square, tight and the joints are strong.

So, now on to the planking.  It's done with tapering strips cut from 2.5mm balsa sheet.  I find planking strangely therapeutic - you can't rush it if you use white glue as I do - a couple of planks go on either side, and walk away for an hour to let the glue get a grip. I built the Model World JU87 a couple of years ago - and the fuse curves in both the horizontal and vertical planes - so planking that was fun - some very strange tapers in that one. Still, it turned out well, and flies straight and level - so I must have built it straight.

The planks extend over the joint with the fuse decking, so I tend to take the cowl off the front of the fuse every few strips to make sure I haven't inadvertently glued the cowl to the front of the fuse - if I have it's a simple matter to free it up - not so if you leave it to the end of the planking.

I'm happy with the planking - a little sanding and a tad of lightweight filler (I use One-fill Polyfilla - I think it's the same as the Modelite filler, but much cheaper weight for weight.  Polycell used to call it something else - and changed the name a couple of years ago to catch me out).





Next is the planking at the front of the fuse, then on to the rear fuse structure - at which point I have to make a new modelling board - my 4' one's not long enough.

Fortunately I have a 6' long offcut of kitchen worktop available - I usually stick 2 layers of cork tiles to a suitable board - to take pins - and that does me well.  So I'll hope to get that made later today ready for the fuse construction tomorrow.

Andy

Hi Andy
Good work going on there. I don't have anything by way of instructions to hand at the moment ...not even a plan sheet but from memory the cowl sides are just too deep to cut out of regulation 100mm wide stock. As a result there should have been supplied an additional "sliver" to glued to make up the "shortfall". Of course as your pics reveal, the lower corners of the cowl are eventually rounded, particularly at the front and I believe you will end up sanding into triangle stock, the angles of which should be tailored to suit that lower corner intersection ..fore and aft that is. I hope I'm right about this ...shooting from the hip so to speak.

You have the triangle across the front ...does the plan not show them along the length as well.

You may all think this sounds odd ...but we just don't have an AOP9 in this country to look at, measure, eye-ball or whatever and so relied on as many pics as we could lay our hands on as a guide. In fact. as far as I can tell there's not even a really accuate set of 3 views of the bird ever been published.

Keep it up Andy ...more coffee!

Hi Brian,

I didn't find the 'sliver', (didn't look for it! since I've probably got enough balsa and ply in stock to build something small from scratch and without leaving the workshop I wasn't going to worry too much!)

Is this what you meant about the lateral triangle bracing?  Fear not, it's clearly shown on the plan - I ended up with these a tad shorter than I would have liked as it took me a while to get the compound mitres just right.



I've now planked the windscreen decking.............just remains to sand to shape then glass cloth the cowl, inside and out.  I hate glassing as I always end up feeling that I've made a mess - even if I haven't, so it will wait until I'm in the mood!  I need to sand up the windscreen decking before completing the fuse - otherwise that's a recipe for hangar rash - wafting a long fuse construction about whilst sanding the decking is just asking for trouble.  Ho hum, I'll do that outside this afternoon while it's sunny.

So, on to the rear end of the fuse construction - a longeron and diagonal braced behemoth in hard 9.5mm square balsa!  Hope the tail feathers are light!

Ordered some 5" Sullivan Skylite wheels today - there's no wheel size given on the plan but reference to the full size suggests that's about what's needed.  Advice taken also suggests it's going to need 2 x 6V batteries and an SM Services battery backer - so the credit card is taking a bit of a hit atm.  I've got a high spec Futaba 35MHz D/c receiver spare - so that'll do nicely.  What's this I hear about some new-fangled 2.4GHz system? 

Andy

Having a busy day today - made the fuse sides last night.  I've got one of those small woodworking machines - a vertical 1" belt sander and a 6" disc combined (cheap and nasty Ch*n*se but it does the job) - the disc sander has a table which tilts and when combined with the adjustable fence you can create compound joints - I would not be without it at the price I paid a few years ago in a B&Q sale.  By setting up the angles I could prepare the various 9.5mm sq components and then make up a kit of parts. You can't rely on the angle graduations on the fence and table, but with a bit of patience and trial and error even I can get some very close fitting joints.

Nearly fell into the trap of cutting up one of the long longerons to make the shorter components though.  I made up all the joint faces on one of the (only) two long longeron stock pieces, then made up the other whilst the sanding machine was set to the correct angles (these fit along the u/side of the fuse - the rest of the stock is too short).  I marked the second one so I'd not cut it up inadvertently, put it to one side, then gaily set off to cut up another piece of stock for the shorter cross braces.  A few minutes later I was wondering where the first of the two long longerons had gone to.  After a quick panic and thoughts of having to make a scarph joint in two pieces of the shorter 9.5mm sq stock, I spotted the missing component, safely put away in the box.   

Having made up the two (yes, handed) side frames I set about adjusting these to fit the cabin structure.  This really needs a clear bench, a cool head, and as the instructions say - measure twice...........and have a coffee.

So, I marked a nice long straight line on my new building board, clamped and pinned the cabin assembly down on the centreline, made up a spacer to set the stern post the required 103mm off the board, and set about cutting and shutting to get it all to fit.  This needed a bit of work, and although the overlaps between the ply cheeks that comprise the rear of the cabin and the longerons and diagonal braces are not quite as perfect as the plan shows, they were only a few mm out.  Once the fuse frames were securely clamped to the cabin cheeks, and the tail end pulled together on the centreline, I made the two cross braces that fit behind the cabin, glued these in with white glue to give me a few minutes working time, and then made up the diagonal braces to get the fuse square just behind the cabin.  I used cyano on one of the diagonal joints here as I needed to force the fuse into square and glue up the diagonal brace at the same time - and didn't have enough hands.  In general it's white glue all the way though. The fuse was about 5mm out of square (in the cross-fuse plane) before I started the diagonal installation, but as you can see from the photos the diagonal braces have squared it up nicely.





This brace needs to be thoroughly gone off before I chamfer up the inner faces of the stern post and add the rest of the cross bracing - so that'll be tomorrow's jobs.

Andy

Today's installment is the gubbins at the rear end of the fuse - consisting of the structures that receive the tail feathers, and the tailwheel.

Tailwheel first.

And immediately a problem.  The manual gives you the dimensions of most wooden parts - including the triangular ply stiffeners and an intervening spacer that glue onto the lower longerons down at the back - but the bits supplied are 5-10mm smaller.  The plan gives the dimensions of where these bits fit - but because the supplied bits are a little smaller, and since they fit into the triangular gap between the fuse sides, these parts would all now fit about 10mm rearwards of the plan position.  That may not be a problem if you like ground looping with a castoring tailwheel - but not me.  The more rearward location would put any crank arm fitted to the tailwheel between two of the fuse bracing uprights - so storing up a space and accessibility problem for the linkages construction.

So I elected to shim out the lower ply plate edges with ply so that it would fit further forward, and make a new top plate to suit from 1/8 ply.  The arrow shows where I added the ply shims.



Having done that, and added the tail platform and fin mounting strip, this is what it looks like. - the metal rule is 12".



I've now finally glued the fuse framework to the cabin assembly  - but more of that tomorrow.

Hope you're not all bored by now and gone off to watch the more 'exciting' builds going on elsewhere on the forum!

It's slightly magical watching it come together.

Dunno about magical tsr!  Although that might come in later - see below. 

Been thinking about locating the servos for the tail feathers, Airsail don't make any suggestions - fair enough - if you can build this kit then you should be able to work out your radio installation.  I'd be inclined to put them down at the tail and not use long snakes.  However, whilst I'd thought that the DLE30 engine I'm using would be fairly heavy in the nose, and help me avoid the dreaded lead, a couple of people have told me that that engine is not heavy - so I need to think about tail weight if I'm to avoid dragging a lump of dead weight around.

Spoke to Terry at SM Services - very helpful, and atm I'm going for an SM Services Opto isolator because with a 2.8m span, the leads to the aileron servos will be long, and I'd rather not pick up noise from the ignition system.  Batteries will be 4.8V on the receiver and 6V on the servos, and a separate battery for the gas engine ignition.  Unless anyone's got any better ideas?  The servo battery could be subC - 3300mAh has been recommended but I'm struggling to find a made up pack to do this - and I'm not keen on making up a pack from tagged cells - I really don't want any electrical power problems in the air.

So the magic might come in when getting the CoG right.  It would be nice to be given the CoG location but I can't find it on the plans or in the manual.  Maybe DH100 can advise?

Moving on to more immediate matters, this morning's work was to complete the fuse construction, ready for finishing.  So there were two metal tube braces to fit from the rear cabin braces to the top of the fuse - needed a bit of fettling but easily done.  The rearward bolts had to be installed at a bit of an angle to clear the cross brace - not ideal, but I think it's OK.





OK, on to the tail...........

RE the tail surface servos ...yes, down the back. Also makes easy work of connecting the tail wheel steering.

RE the CG ...start at the main spar and you'll probably find it's a little too far forward. As a rule of thumb for this type of aircraft, i.e side by side, I note where the pilot(S) is sitting and all things being equal the CG is most likely under his buttocks! (not the case for tandem ...e.g. a Tiger Moth where it's located pretty much where the passenger/instructor would be.) This of course is not gospel ...just an observation.

To throw a spanner in the works, I've always been unhappy about the flat plate tail surfaces and have considered fitting a symmetrical section rear end set to the model.  On the full size, both the vertical and horizontal units are quite thick in section and the tailplane should be a little further forward.

The strange tailplane mount platform as per our model is not what it should be. In reality this is just a fairing to blend in the front of the tailplane, which is mounted to the top of the fuselage. If no fairing was fitted there would be a corresponding gap between the LE of the Tailplane and the top of the Fuse.

However, it's like a lot of other things I thought I might do one day. I'm so busy being busy I don't still don't have time to do what I really want to do.

Good work. 

Hi Brian,

Many thanks for the advice, again, much appreciated. 

I hadn't studied the full size tail arrangement to date - but I will now.  I'm in the process of all the tail feathers shaping - I have already fitted the tail platform, and the fin support plate - but I'll have a look and see if I can make it more 'scale'.

I was going to fit individual servos for each elevator half, so it would be three servos down at the back if I did it that way - and I'm still a bit concerned about tail weight - some of the 9.5mm square tail framing is fairly hard balsa - it doesn't feel heavy, but once you've added Solartex (i.e. RAF camouflage scheme)  (I may use Profilm if I go for a yellow scheme) it all mounts up.

Still might put the servos more midships and use the heavier grade Sullivan snakes (blue ones?) instead of the red ones I usually use.  Hmmmm..........

So many things to think about!  Kit (or plan) building beats ARTFs every time!   

Andy

Hi again.

Once you see the full size tail arrangement the mounting and fairing becomes very obvious. Also, the tailplane is sufficiently forward of the stern post to allow for what ever elevator control horn arrangement is fitted ... to the full size and not foul the stern post.

I hate external horns on a scale model when they should be internal.  If I recall correctly my drawing expert has CAD drawing of the proposed (still to be born) symmetrical tail surfaces for this aircraft. I may be able to send you a set of laser cut ribs ...or at least the drawing so Traplet or Slec could cut them for you.  You could then have a U shaped Elevator joiner with a central, internal horn. Any help?

Cheers ... Brian

Hi Brian,

I've had a look at some full size pics on the 'net, and I can see what you mean - the elevator rotational axis on the full size is just in front of the stern post, which would allow you to devise a horn to fit inside the fin - tight, but possible.

I'd be interested to see the drawing you have.  I've more or less completed the tail feathers, but not installed them.  The horizontal stabiliser on the kit looks a bit chunkier than on the full size - pro-rata, but the kit section does taper towards the LE - as does the fin.

I have some time before I need to attach the feathers - I'll cover first - so if I could have a look at the scale drawing you have I could build another tail. 

I can't show a pic of the H stab as I've attached the tips (horns), but it's essentially the same section as the fin - see below, which seems to me to be reasonably scale.



Anyway - more on the build details comes next....

OK - back to the planned build, as oppposed to what might happen with a revision to the rear end!

I've always had trouble getting my control surface hinges just right - and I know you can buy jigs for the Robart pin hinges supplied by Airsail in the kit - but I made my own for this build - some scrap 13mm ali box from the fuselage former I made for my Stuka build, some ply cheeks epoxied on, then some balsa shims either side to make it a snug fit on the 9.5mm square tail feathers frames.



These turned out to be my best ever pin hinge installations - so I'm pleased with that.

The dry fit of the framing is shown here:



Skinning next.............