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    Wing Spar - design / bonding pultrusions

    I have a quick question: is the attached basically the best / most foolproof way of doing things? Red - Pultruded carbon strip spar cap already bonded. Green - PVC Foam Black - continuous wrap of carbon overlapping for an inch or so in the middle of the shear web. And also -bonding pultruded...
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    QC Question...

    Opinions wanted please! Does this repair look resin starved or fine?
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    Refinishing gliders

    Mine's getting a bit close to that time I think (LS6A 15m). I could have a crack at doing the leading edges and the tailplane myself to add a few more years onto it but then I could just get the whole thing done properly... Anyone had this done recently & got ballpark figures for cost / a...
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    Holiday reading ideas?

    I'm being made to go on holiday! Anyone care to recommend any great books to read? The wife thinks 'manuals' and 'textbooks' are not appropriate for holiday and, to be honest, she's probably right.
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    Matty's Marvelous Modular Monstrosity

    I've not thought of a name for this thing yet so it's either MMMM or Iteration 9. I'm starting a sort of build log here because I've actually started building the thing and the bit I built first has just passed its first test so Iive run out of excuses for asking dumb questions and not showing...
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    SSDR 60% Hurricane

    I think this was mentioned in the Hurricane Mk 103 thread but I found a presentation he put together on how he did it which is quite impressive. https://www.aerosociety.com/media/10193/martyn-ing.pdf
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    What did you screw up on your Airplane project today?

    As I was making about the 10th potentially expensive, slow motion screw up on this project I thought "what we need is an 'inspirational' thread that shows that everyone does it...". Here's a picture of the foam cutter starting at the bottom so the cut above is displaced rendering the whole...
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    Have I got my spar bending / shear diagrams right?

    HIYA. I think I've got a handle on how the bending / shear loads work out in a two piece wing with sailplane style pinned overlapping spars. But there's a good chance I'm wrong so if I am could someone let me know and try and point me in the right direction please! Structure overview...
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    How much to overlap individual plies in a layup

    I think I'm having a brain fart and definitely used to not even think about this. How much do you overlap two pieces of fabric in a hand layup? if you can't make a skin from one piece of fabric the whole length. An inch? Two? And does it make a difference if it's woven or bi-ax (with bi-ax the...
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    Rate my Flaps...

    I've read a bit on slotted flap design here, and gone through Theory of Wing Sections and the rule such as it is seems to be to make it look about right. What do yo reckon? Looks ok? I've gone for just over .01c gap on a 25% flap chord. Airfoil is Wortmann FX 79 K 144/17. Regarding actuating...
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    CNC Foam cutter

    I just made one - turns out it's really easy and pretty cheap! Who'd have known? Basically you just follow the instructions the RC guys have worked out (link below) then make it a bit bigger. All in about £250 and with some mods it'll turn into a light duty milling machine - should be good for...
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    The state of the Art?

    Seeing as we have this shiny new forum to fill with rabid fan boy rantings I thought it might be an idea to start with some links to successful electric homebuilt airplanes. The more detail on motor/ESC/batteries the better! I'll start with Dale Kremer whose E-Lazair project in a lot of ways...
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    Carbon Spar cap pultrusion sizing

    I've got a question for you knowledgeable types: I've sized my spars and found a supplier of top quality carbon pultrusions [ https://www.dpp-pultrusion.com/ ]… The question is do I want to have a very small number of large strips, or a larger number of small strips? If I go 16mmx2mm I need...
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    Tail structure sizing

    I've chosen my layout, my airfoils, my tail volume and my flight envelope & done some basic stability calcs and it all checks out... So now I can start analysing structures in some more detail! For a conservative first pass on the horizontal tail structure can I just run a Schrenk analysis on...
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    My Project: Electric single seat Microlight

    Probably about time I put some details of this up and ask for feedback! The idea is for an all composite, very efficient single seater (looks a lot like a low aspect ratio glider & will use a whole load of glider techniques). Basic spec: 250 km range 80 Knot Cruise 35 Knot Stall speed (SSDR*...
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    Wing Locating Pins & Main Pins & Spar caps.

    I've got a question for you people! I'm planning on having removable wings and joining them in a glider style - Bending loads carried by spars that overlap inside the fuselage with two big pins going into bushings to join them together then lift loads transferring into the fuselage via four...
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    Infused / Wet lay / Bagged wing skin

    I've been enjoying this 'Wet Hardshell' thread and it got me thinking... Infusing a sandwich panel in one hit comes out really heavy because the foam takes up loads of resin so could you infuse the outer skin, wait till it gels, unbag, add foam and a pre-wetted inner skin with peel ply /...
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    Personal Parachute vs whole aircraft ballistic parachute

    Given I'm designing from the ground up I can go either way. But which way? And why? Oh yeah: Single seat!
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    Wing Mould Test

    I'm putting together a test mould to see if I can infuse the whole D-box and upper skin in one shot. Lower rear skin including contour for the flap to be made separately and bonded into place once all the internals are in. Spar to be slightly ahead of max thickness so glue can be applied and...
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    70kg / 154lb deregulated category - what can you build?

    Apparently here in the UK we finally have truly deregulated flying but it's a lot stricter than Part 103 over there in the States. What - if anything - can you do with 70kg? Sub 70Kg Microlights. Strictly speaking these aircraft are termed Self-Propelled Hang Gliders (SPHG)! In April 2017 the...