discussion SE5a CONSTRUCTION BEGINNING TO . . .

[Guest]

and I only wish my workbench was as immaculate as Grahame's too !!!!. Nice to see that sort of work space, clean. clear, Uncluttered and the tools all neatly put away but to hand when required.

Regards.......Mark.

 

[Guest]

Very interesting thread with great workmanship, that I follow with the greatest interest.

 

[Greyhead]

Barry

The undercamber is a slight cause for concern, in the past I’ve had the covering pull away in this area, in that case it wasn’t too much of a problem because it was a Solatex non-painted finish on a glider, but the SE5a is another matter.

I’m seriously considering stitching the covering as per full size, I’ll experiment on the centre section first and see how that goes, after all the stitching would have to be simulated anyway so why not go the whole hog?

Mark

It wasn’t always so!

I’m making a special effort to keep things tidy after the better half “donated” half of her half of the shed so I could build an “extension” to my workroom. But I must say that now I’ve retired the 5 minutes cleaning up after each building session doesn’t seem such a waste of valuable building time!

Grahame

 

[Guest]

Every one is completely differrent as regards workbenches, if you remember Nigels workbench competition we saw that.

I'm with Grayhead, I can't handle not having everything neat and tidy and in its place. I am, of course, very fortunate in having a lot of wonderfull space but I still couldn't work with an untidy workbench.

 

[Greyhead]

The first rear frame is built over the plan.


View attachment 262515


Using an open framework structure has advantages; it is quick and easy to build and very light but it is inherently weak compared to sheet material, to make matters worse the longerons have to be “broken” where the fuselage starts to taper towards the tail.


The strength can be greatly increased by the use of gussets, as always it is a trade off of strength against weight, I use 1/64th ply, which I consider to be a good compromise. One of the modelling magazines had an article that measured this increase in strength and amazingly even gusset made from brown paper made a significant difference.


View attachment 262516


The second frame is built over the first, which is covered with Clingfilm to stop any unwanted adhesions.


View attachment 262517


View attachment 262518

 

[wonwinglo]

Grahame the correct aviation term is 'Biscuit' every full sized wooden aeroplane uses them in the construction,and yes they add fantastic extra strength,I think that the use of your 1=64th ply is an ideal application,where did you manage to get that spruce from ? a very scare commodity these days.

 

[wonwinglo]

***Grahame,can I suggest a compromise situation here with the rib stitching ? to stitch the lot is a mammoth task,why not loop stitch three positions on the aerofoil and simulate the rest ? first make sure that there is plenty of balsalok onto the ends of the ribs on the underside,iron on the tex but do not tighten up the fabric yet,cover the upper surface same here do not tghten up yet,next place your preferred ribbing tapes ( perhaps cut from solartex strips ) onto the rib edges,make your three critical loops onto each rib which will hold the fabric on the under camber,next simulate the true stitching by laying pins at strategic points,wind thread around each pin,tack run thin cyno around but do not touch the pins,remove pins,apply a thin coat of pva to lock everything in place,now tighten up the covering working top and bottom of the wing by use of your heat gun.

Having seen some excellent models that have been rib taped at Old Warden scale days it can be done but is time consuming to say the least.

BarryThe undercamber is a slight cause for concern, in the past I’ve had the covering pull away in this area, in that case it wasn’t too much of a problem because it was a Solatex non-painted finish on a glider, but the SE5a is another matter.

I’m seriously considering stitching the covering as per full size, I’ll experiment on the centre section first and see how that goes, after all the stitching would have to be simulated anyway so why not go the whole hog?

Mark

It wasn’t always so!

I’m making a special effort to keep things tidy after the better half “donated” half of her half of the shed so I could build an “extension” to my workroom. But I must say that now I’ve retired the 5 minutes cleaning up after each building session doesn’t seem such a waste of valuable building time!

Grahame

 

[Guest]

Hi Greyhead i had not seen this thread since it started up and i have to say it has come along leaps and bounds.

It looks lovely so far and you have a great attention to detail.

am just wondering if you where planning on painting this? If so i have always loved the RAF colour scheme for this old beauty!

 

[Greyhead]

After gluing the rear framework to the front section the longerons are cut ¾ through at the “break” point and carefully cracked to allow them to be pulled onto the rear formers keeping the sides straight. On many aircraft, the Elf for example, the sides aren’t straight; they are pulled in at the rear and allowed to take up the natural bow imparted be the spring of the wood. I used a variation of the “3 pins method” to ensure a straight fuselage i.e. in this case the front formers had marks drawn on the centre line instead of pins.


The framework is made from 1/8th square spruce; when working with this wood I’ve found that the glue takes a lot longer to set, even cyano takes its time!! So it’s essential to use lots of clamps and leave everything to set completely before removing them.


View attachment 262519


At this stage the rear fuselage is quite flexible, not to say fragile, but with a few more biscuits it’ll firm up.


Barry


Strange they’re called biscuits, in the woodwork industry a biscuit is an elliptical shaped piece of wood that is glued into slots cut in two pieces of wood to strengthen a butt joint, very similar to what we have here but significantly different.


Richard


The colour will be PC10 and “natural” linen.

 

[Guest]

Well Grahame the more I watch this thread the more convinced I am that you are building a real aircraft in miniature. You are following so many techniques used in the real construction you could scale this up and fly it!

Absolutely fascinating to follow and so much appreciation to you for sharing it so closely with us all. You put more time and effort in to the build thread than a lot of us put into making the model!!

I can't wait to see this beauty fly for the first time.

 

[wonwinglo]

Grahame,I was just thinking how similar she looks to the Elf in the view here from the rear ! not generally realised is that the S.E.5A had a great influence on designs even years afterwards,as Richard says it is a replica in miniature,having been involved in building full sized and scale models there is no doubt that models are the most difficult working to the smaller scales we use.

By the way congratulations on your retirement from teaching,you are certainly enjoying it and putting your time to good use.

It is also surprising when you have continuity with a project how well things take shape,how did you find time to do full time work ?!!

 

[Greyhead]

Having added a few more 1/64th ply biscuits the framework was a lot stiffer, however I still wasn’t happy about the strength at the “break” line so I removed the cross braces and epoxied some carbon fibre tows over the joint.


View attachment 262520


Now that’s a lot stronger!


View attachment 262521


This raises the question why didn’t I do this in the first place? I go on at length about the virtues of carbon fibre tows and then I fail to spot this obvious application; must be something to do with age!

 

[wonwinglo]

Lots of extra strength with little weight increase,excellent tip.

 

[Greyhead]

In my opinion it’s never too soon to start on the instrument panel; they’re a mini project in their own right and whilst enjoyable to do it can be a bit frustrating because the model doesn’t seem to “grow” during the time spent on them, so I like to intersperse the work with the main build so keeping the interest going.


Here’s a photo to show what we’re aiming for, it seems a bit daunting but the idea is to concentrate on an instrument at a time.


View attachment 262522


I’ve made a start; that’s the easy bit!


View attachment 262523


This will be the final position.


View attachment 262524


It’s always useful to check that “Pete” will fit!


View attachment 262525

 

[wonwinglo]

Thats some office Grahame,and one that Pete will be quite at home in,for a WW1 panel it is fairly complex and there is a most un-usual feature that I wonder if many have spotted ? the fact that the instrument panel slopes,this is unusual in that most gyro instruments function best in the upright position,but the proof is there as the panel certainly has a slant to it,perhaps this could be something to do with the flying attitude of the aircraft in flight,who knows ?

The panel and cockpit itself is a model in its own rights and just know that you will do full justice to this important feature.

There are some un-usual features there including the advance and retard lever.

Best of luck with the instruments,they should present a real challenge to ingenuity and application.

 

[Greyhead]

Tip of the day

Starting work on the instrument panel, which has several small pieces of ply and balsa, has reminded me to mention a very useful addition to the workshop.

Like everybody, I suspect, I have a draw (in fact 2 draws) full of “useful” sized off cuts but I also have this old ice-cream container into which I put any small off cuts.

Believe me, there will come a time when you need a piece of 1/16th balsa about 1” x 1” and all you’ll have is a 36” x 4” plank that you bought especially to sheet the leading edge, then you’ll wish you’d not put those little pieces in the bin.

 

[Guest]

Yep Grahame,

I will certainly agree with you on that last tip, you never know when those little offcuts will serve a purpose and better to use them rather than waste a whole sheet of new wood. I have a tub full of offcuts too !!!

As for your comments on glueing spruce wood, I have to agree with you there, possibly the longer drying time is due to the wood being more dense (very closed grain) and the glue not soaking into the wood in the same way compared to say balsa or ply due to closed grain....Spruce tends to have a smoother surface compared to the other woods....even when you try to rough it up a bit for a keying surface for the glue.

And as for the Model, Congratulations, she is really coming along nicely now and really starting to take shape....a real pleasure too look at.

Regards......Mark.

 

[wonwinglo]

Saving wood offcuts has been a weakness of mine for years,they do take up a lot of room so what I have found useful is one of those wheelie bins which lives outside,any potentially useful timber whether it is ply,balsa etc goes into the WB,however it is best to set a criteria on what you consider to be a useful size of offcut,otherwise it does tend to build up !

In case anyone is having doubts about how dry the wood keeps,no problems as those swing over lids seal well.

 

[Guest]

in the photo of the instrument panel there is 2 half circular bits cut out of the little storage box thing ( dont know its name)

are you gonna sdo that to the models panel aswell?

 

[Greyhead]

Iain

Yes that’s done now; the photo was taken at an early stage. The “storage box thing” holds a spare magazine for the Lewis gun, there’s another one on the cockpit floor between the pilots legs. Sounds a bit dodgy to me!!

After adding extra balsa to the back of the panel the support bracket has been removed and replaced by 2 made from litho plate.

These things do have a tendency to “develop” as they go along.

Grahame