Legrand Simon LS60 build blog

[Peter Miller]

It is stange that a high wing cabin aircraft can have as much appeal as an empty kit box and yet a similar aircraft can have so much character that one just has to build it.

 

The Legrand Simon LS60 is such and aircraft. I loved the shape and when you add in fully slatted wings and slotted aileorns and flaps I just had to build it.

 

3 Views were easy to find. well. I found the 3 view first.

And then I had to draw the plan. For such a simple aircraft this caused an awful lot of head scratching but it was finally done.

I next cut out a kit of parts. Well, most of them, over half a sheet of 1/8" ply was not enough, those formers are BIG. 6" X 8"!

 

I started on the wing first. My normal process of building on top of the lower sheet. Lower spar and ribs

Then add the top spars and leading edge.

The wing and fuselage borrow heavily from the Wittman Tailwind method of construction

The hinges will be made from SLEF Neata horns so I needed block in the rear spar. These were made up in lengths and then cut and fitted.

The servos will be mounted on ply plates. These will be screwed to bearers glued to the wing. Simpler than my old method.

While things were drying I made up Fomer 3. THis has the strut mount and undercarriage fitted. Because the undercarriage is behind the former I could get away with a plastic saddle.

This side shows the undercarriage

And this side shows the strut attachments

[Simon Chaddock]

Peter

Look very nice and a fascinating plane to model.

 

Nice to see somebody doing it truly from scratch. How big is yours going to be?

Full slats and slotted ailerons will be interesting but just how effective they are at model sizes is always open to discussion, unless of course you built a set of identical 'simple' wings to compare!

 

I shall be following this with interest.

 

[Peter Miller]

Model will be 63" span and powered by an OS FS 40 Surpass.

 

Slots and slotted ailerons worked beautifully on my Turbulent about 30 years ago. I had full aileron control at incredible angles of attack. I expect this to be the same. Or should I say "HOPE"

 

The LS50 is an almost identical aircraft but without the slats. I show the rib shape for that version and the tail shapes for it so anyone who wanted to can build the simpler version

[Stephen Jones]

Hi Peter ,

 

That`s a very nice build subject lots of interesting lines and your build looks impressively good . May i ask if the wing is being built on a thick block of cork as some of those pins look as though they are pushed all the way down to their head .

[Peter Miller]

No, I use cork tiles on a melamine covered chip board. The cork is about 3/8" thick.

 

I use short map pins when holding down sheet as they can be pushed all the way in and the heads hold the sheet down well. I also use them for holding sheet to the structure. Especially leading edge sheet to the leading edge. I use clamps to hold the sheet to the spar.

 

They are cheap and can be bought at and stationers. Only snag is that sometimes the heads come of when removing them. If you don't spot this the pin can snag on things.

[Peter Miller]

Well, Managed some more over the last couple of days.

 

The wires in the wing roots are encapsulated by pouring resin in round them. The webs on the other side of spars must be resin tight.

The paper tubes are fitted by wrapping paper round a dowel and feeding them down the wing. Then let the paper unroll and glue.

Note the hardwood block for the wing strut mount. Drill this at this stage because finding the right spot through the skin is not so easy.

 

At last I can skin the wing. Here glue has been applied to all edges and the sheet skin has been pinned down to the leading edge with short map pins.

And then we just plonk two Argos catalogues down over the wing to hold the sheet down. Other catalogues can be used but you can just walk into Argos and pick them up.

 

Edited By Peter Miller on 05/07/2011 18:47:17

[Stephen Jones]

Thanks peter for the reply ,

 

good tip , often been a problem for me keeping every thing pinned down , i shall now go and get myself some map pins , cork and of coarse some argos catalogues as opposed to the large batteries i have used in the past .

And of coarse the catalogues will keep even weight around the curvature .

[Peter Miller]

You will notice that one of the catalogues is well thumbed, the other is brand new but the same edition

 

This is the most complicated and trickiest wing that I have built in many years.

 

Started on the fuselage as well. probably post the next stage tonight.

 

I had to buy my cork tiles from Ebay. Seems that theyare not infashion these days.

 

Also buy your map pins on Ebay. My stationers wanted £3.65 per hundred. Same ons £1.98 plus postatge one ebay.

Edited By Peter Miller on 07/07/2011 08:02:28

[Peter Miller]

So now we have a basic wing. The next stage is to make the shrouds fr the slotted ailerons and flaps. I used strips of 1/64" ply soaked in the bath for about 6 hours and then wrapped round a 15 mm dowel and bound with bandage.

The hinge blocks have to be drilled. The hinges will be made with a SLEC Neata horn with one leg cut off. If you leave both on you will have to drill through the lower spar.

I made up a simple jig for the drilling.

The top sheet has to be chamfered and then the ply can be glued in place. Pin it a the bottom and clamp it to the top sheet with stiff strips of wood to make sure that the trailing edge is not wavy

The ply is cut away at the hinge location. The hinges will be fitted after covering with CA for the pin and epoxy to hold it in place.

The leading edge capstrip is added and then the leading edge of the wing is shaped using a gauge. The leading edge of the flaps and ailerons are shaped in the same way with another gauge.

The slats will be made later when I can work outside with the power plane and surform.

[Peter Miller]

At last I can start in the fuselage construction. All the parts have been cut out and F-3 has had the U/C and strut mount attached.

Pin one side down overlapping the edge of the table and glue on F-1, F-2 F-3 and F-4. Nose use of a lot of set squares. You can't see them all! This is important.

When dry you can add the other side. Still using set squares to make sure nothing moves.

The front of the engine mount box is laminated from 1/8" ply. one lamination fits inside the box, the other over the front. I use a hole saw to make the hole for the neck of the fuel tank and seal it with silicone

I drill though the mount with a long series drill and then open the holes up for the blind nuts. These fitted now to make sure that everything lines up before removing the engine mount.

The engine mount box is built into the nose. Note copious use of triangular wood in all corners. This makes everything much stronger.

 

The sides have to be cut at F-5 and the 3/16 sq longerons cut through flush with the rear face of F-5. Do not cut into the ply doubler!!!

Withe the plan pinned down and the undercarriage overhanging the end of the bench we can pull in the rear of the fuselage and add the rear formers.

That is a BIG fuselage cabin.

Edited By Peter Miller on 07/07/2011 19:52:06

[Peter Miller]

I missed the photo showing the leading edge being shaped with a gauge

[Tom T]

Looking very nice Peter!

 

I love watching these sort of things unfold! Ill definatly be keeping my eye on this thread.

 

Tom

[Peter Miller]

I am learning too. The aileron shroud and the method of hinging is soething tta I have just developed.

 

The cowling with be a variation of a method that I use for radial cowls,

[Peter Miller]

This is the critical part, making sure that the wing wires slide into the tubes easily. Mote that the wire binding for the tubes has not been soldered at this stage.

Another view of the cabin area during fitting the wings

The 1/8" sheet upper sides being glued into place.

Stage one of the rolled sheet turtle deck. The wood is lgued to the sides and left to dry.

The wood has been wet on the outside and then curved over while applying heat from an iron or heat gun.

This is the sheet platform for mounting the fin and tailplane. As will be seen, the fin is very thick at the base.

[Tom T]

Looks really good Peter! Can't wait to see the rest of the project and the finished product!

[Josip Vrandecic -Mes]

Hi Peter ,a lot of work .....but ,after all,she will fly magically....useful airfoil, minimum stall speed...enjoy.

Cheers

Jo

Edited By Josip Vrandecic -Mess on 11/07/2011 16:40:16

[Peter Miller]

IT is going to be a bit heavier than I like.

 

As for the wing, well, I have learned not to be over confident.

 

[Peter Miller]

Right. Back again.

 

The fin and rudder are built on the spars and standing upright as shown.

 

The fin is covered in 1/16" sheet, The rudder has capstrips up the spar and over the ribs.

 

The bottom of the fuselage is covered with sheet. The radio hatch is left open for the time being

 

The second layer of 1/8" sheet is added over the turtle deck. This provides a rebate for the cowl.

The underside sheet is stepped at the front to make a rebate for the bottom of the cowl.

 

 

 

[Peter Miller]

Now we come to the cowl. This uses a technique that I developed for radial cowls formed over a tin can. Here I have used it over two formers.

 

The two formers are glued to a 1" dowel or in this case a 1" tube.

 

The first stage is to glue a layer of 1/64" ply to the formers. This will have to be made up from pieces as the ply will not be wide enough. The grain runs along the cowl.

 

The joints must be feathered to make a smooth surface.

Another view of the cowl with its first layer.

The second layer is 3/32" balsa. This is applied by gluing down one edge with CA. Then flow a good amount of CA into the joint and roll the cowl over on a flat surface this drives the CA along the joint. You may need to add CA as the roll continues.

 

The flatter areas can be glued with impact adhesive. The small piece of wood on top is for the hold down screw.

 

Underside of cowl at the same stage. Note the strip of wood across the cowl to take the lower hold down screws.

The last layer of 1/64" ply is now added. This can be done with the CA method or another little known technique.

 

Paint both surfaces of wood to be joined with aliphatic resin glue. Make it a smooth coat but don't make it too thin. Leave it to dry completely.

 

The 1/64" ply can now be ironed onto the cowl with a hot iron. This will polymerise the glue and make a permanent bond. This is a "ONCE-ONLY" operation so don't get it wrong.

 

It works best with thin ply but I have ironed 1/16" leading edge sheet down but it does make the wood go brown in places.

Here the pieces that go round the tight bends have been ironed on. Note feather edges. These will need to be coated with more aliphatic resin.

The basic cowl is now complete and the rear former can be removed. It is very rigid at this stage. The cowl can now be trimmed to match the fuselage.

Starting to built the chin intake. This is 1/8" sheet.

 

And the moment of Truth. does it fit the fuselage? Yes, it does.

 

 

 

[Peter Miller]

Well Now for a bit more on the build.

The slats are formed by binding wet layers of wood to a preshaped former. One layer of 1/64" ply and four of 1/16" balsa. Once dry and it takes a day or two, glue them together and bind them down again.

 

Shape the completed slat with a template.

 

These are the slat supports cut from 1/4" ply, The end ones are chamfered on one side only,, the middle ones are shaped as shown.

The fin is glued down to the 1/8" sheet platform. This also provides a good mounting for the tailplane.

The top stringers can now be added.

The rudder horn is cut from epoxy PCB board.

It will be glued into the base of the rudder after covering, This is for a closed loop system.

The aileron hinges are fitted after covering. The single prong of the SLEC Neata horn is glued in with CA then the gap in the aileron shroud is filled with epoxy to secure the horn and stop it moving.

The cowl is a bit tight and the engine mount will need trimming as shown

I had to use a Just Engines 150 degree elbow to mount the silencer. Quite a large hole is needed to allow it to turn and for the spanner on the locknut.

This is the hole for the silencer and also the hole for the needle valve.

The clever bulges for the occupant's elbows are an unusual feature of the aircraft. They are made with soft sheet carved to shape. A piece of 1/16" sheet will complete the fairing.

This is the final shape of the cowl intake. Sorry, I should have rotated it.

Edited By Peter Miller on 24/07/2011 12:28:48

[Peter Miller]

Well, it has been a long time since I updated this blog but now the model is ready for test flying. Lets catch up on some of the details and the completed model.

The battery is strapped in behind the tank to give it plenty of support and get it as far forward as possible.

 

The reciver in the boxx made between F-4 and F-5. The windscreen is made from two parts. One is formed round a dummy leading edge to complete the wing cut out. The other is a simple curved windscreen.

 

Underside view of the radio bay. Note the idler bellcrank for the closed loop to the rudder. Makes adjustment easy and also removal of the servo is quick and simple.

 

I changed my mind and fitted an SC 52 FS because the weight was climbing and I felt that the FS 40 might be struggling. FInal weight is 6 1/2" pounds. Not as bad as I had expected at one stage.

 

Compare this with the heading view of the blog. Leg fairings have been left off as they tend to suffer in heavy landings.

 

The orange leading edge is the slat. a fiddly job to do. The LS 50 would be easier. No slats.

 

Slats are more visible here. Note small ailerons and the big flaps. Both are slotted to allow air to flow over them. Elevator is nice and simple even if nothing else is.

 

The cowling is complex but actually not had to build. Fitting ith when the FS 40 was installed was easy. When the SC 52 is fitted it calls for some bigger holes abd some chinese puzzle manipulation.

 

Another view of the cowl and windscreen.

 

The top hatch is essnetial for connecting the servos up when assembling the model, It also makes a great carrying handle. Hinged with tape.

This view also shows a close up with thend of the slat.

 

There are asome more general views in my "odds and Ends" album,

 

The next lot posted on this blog will be the flying shots or the end results.

 

 

[Stephen Jones]

Wow , that looks really great peter, , looking forward to the flying bit .

[Ton van Munsteren]

Hi Peter,

 

Woooo you did a great job model looks really nice looking forward seeing pics and hopefully a vdo of the maiden.

 

What can I say more than have fun doing the maiden.

 

Ton

[Peter Miller]

Well, Sunday wasn't as sunny as I would have liked, just the odd brief sunny spell but it was almost calm so test flights were made.

 

The model flies rather like a KK Super 60 with ailerons. It takes off in a very short distance without flaps. DO NOT USE FLAPS ON TAKE OFF!! We found out the hard way.

 

It will fly extremely slowly. It can do loops and rolls

 

It will drop a wing if you really push it but that can be picked up with the ailerons.

 

No nasty tendancies. In short a nice model to fly.

 

[Ton van Munsteren]

Hi Peter,

 

Congrats on the maiden it looks great in the air and what a lovely shape the model has its really has special looks.

 

The tail looks even bigger in the air than on the ground must be super stable , was kinda surpriced that you mention that it would drop a wing when you push it.

 

Is wthere washout in the wing.

 

Whats the story on the flaps using on take off or better not using on take off.

 

Ton