SE5a CONSTRUCTION BEGINNING TO . . .

[wonwinglo]

Now that is impressive Grahame,even if you had cut them out individually they would never be as clean cut and accurate as you have proved here.

[Greyhead]

Although it was a relatively easy job to make the 64 identical wing ribs, being an SE5a it’s not as simple as that! In fact every rib needs to be altered; the mass-produced ribs were a conglomerate of all the rib profiles.


The 20 “aileron” ribs are cut vertically just behind the rear spar hole, these are the only ones that need the rear support tab, which is removed from the remaining 44 ribs; the riblets also have their support tab removed.





With hindsight it would have been easier to make separate templates for the riblets in the first place as I’ve made them now to remove the tabs; it was easier than altering all 72 individually.

[Greyhead]

One thing I do like about building wings is that you get a lot of model for your effort. A couple of hours after starting and you could convince yourself that the wing is almost finished!





The carbon fibre tubes used for the spars and the leading edge add great strength to the structure, even at this stage of construction.

[Greyhead]

Wing tips are very vulnerable to “hanger rash” but this method makes them really “ding” proof and is also reasonably light.


The core is 1/16th balsa, cut undersize by the appropriate amount, and then layers of 1/64th ply are glued to the edge; to match the carbon fibre leading edge I’ve used 5 layers of 5mm strips.





Using just 3 layers of 1/64th ply is sufficient to make a really tough wing tip.

[Guest]

thats alot of ribs

seems to be coming along good though

[Greyhead]

The flying wire attachments are fixed to the spars by epoxy and binding with button thread; I didn’t want to compromise the spars by drilling holes at these high stress points. For some unknown reason the inner and outer brackets are of completely different designs.


The inner is bent from thin brass sheet.





The outer is from 0.5 mm steel.





Next to the bracket is the fixing for the inter plane strut and once again it’s a closed loop adaptor! They will enable some fine adjustments to the lengths of the struts and also allow a degree of “span-wise” movement between the top and bottom wing halves, which I think is advisable as they will be permanently joined by the struts, it should help when sliding the wings / fixing rods into position on the centre section.


One wing finished, now I’ve got to repeat the exercise another 3 times!





To alleviate the boredom I’ll do a bit more detailing to the fuselage in between!

[Guest]

Hi Grahame. Great job! And thanks for sharing your work with us. How are you hinging the ailerons? I used carbon fiber tubes for my spars, but switched to balsa at the ailerons. I couldn't figure a way to hinge with the carbon fiber.

Steve

[Greyhead]

Steve


The aileron hinges will be the same as I’ve used for the rudder and elevators, both of which use carbon fibre tubes.


The hinges consist of a brass yoke with a brass tube soldered to it and a piano wire hinge pin.





The yoke goes over the carbon fibre tube and has a retaining pin fitted through the 2 holes to prevent the hinge being pulled out, the piano wire hinge pin has a brass keeper soldered behind the control surface leading edge for the same reason.


Grahame

[Guest]

Grahame, Thanks for the info. It's always amazing to see how many ways there are to skin a cat.

Steve

[Greyhead]

I have recently received some research material from a fellow SE5a modeller and it has raised a query about the dihedral angle. To save me writing it again, here is a copy of an email I sent:

I've now read the articles you sent me and there is lots of very useful information in them; thanks again.

One thing that is a bit of a cause for concern is the dihedral angle. I'd read several references on the Internet to the angle being 5º and sometimes being reduced by 1º or 2º in the field; I had assumed this was correct because it was confirmed from different sources.

In one of the articles you sent me it says the dihedral angle is 3º 20’; this is very precise if it’s a “guesstimation” so I assume that this is the true angle obtained from factory drawings. Some modifications to my model would appear to be in order; luckily it’s not too late, the wing rods haven't yet been permanently fixed.

To make matters worse I've repeated the 5º angle in my posts in your thread, as well as my own, so that would appear to anyone searching the Internet to be extra corroboration from myself. I'll have to edit the posts to include this “new” information.

Just goes to show that you shouldn't believe all you read on the Internet!

[Guest]

Hi Grahame. I agree with your statement. Don't believe the 3deg article either unless it can be backed up from other sources. I have six different sets of three and five views. They all show 5 deg dihedral. Also I have it in writing in two publications ( WWI Areo and Squadron/Signal). Different field mods were made to just about everything on this plane, but unless you know that the plane you're modeling had a different dihedral, I'd stick with the factory 5 deg

Steve

[Greyhead]

I did a temporary rig of the top wings using both 5º and about 3.3º and to be perfectly honest I really couldn’t tell the difference when looking at the model as a whole so I’ve decided to stick with the 5º that I originally built in to the mounting blocks; anything for an easy life!

Out of interest Steve do your drawings have the 5º angle written on or have you measured it with a protractor?

[Guest]

Hello Grahame,

that was quite a job to read all the post since my last visit to scale models. But once again I was highly impressed. The photographs in addition to your comments show that it's always worthy to think (and make) over every single detail till you're satisfied with the result. Great job.

Greets from Germany,

Dirk.

[Guest]

Hi Grahame. WWI Areo Publishers lists 5 deg dihedral in the specs. The drawings I have are scanned into a CAD program on my PC. I draw a line from tip to tip and then along eachleading edge. The program gives the angle anywhere from 4.8 to 5.1 for the six front views that I've checked.

Steve

[Guest]

Hi Grahame

Ive just come across this thread whilst looking for info prior to building a DB sport and scale kit at 1/3 scale.

All I can say is you have really inspired me AND given me all the scale info I need.

Keep it going!!!