Graham Davies 3

FB3, foamboard is the stuff often use to back photographs for displays. It's light foam laminated with paper on each side. Depron is lighter, but this stuff is quite stiff. It's also ready to be painted, or drawn on! I may do a blog. I'm learning as I go and I'm sure others have already trod this path. My thoughts are; let's not moan about that lack of wood, but try something new. What have I got to lose? So far, about £8! Rich, Yes, sign me up. Are don't see any significant risk here. After all, my 1/4 scale saturn 5 rocket made from lark's spit and rizla papers and powered by carefully collected cattle fart was highly successful. Our only amateur Moo (n) shot... Graham

It's been quiet on this lately. Once this came to light, I started thinking. And then I got unnecessarily excited! So, rather than worry about what I can't do, I have been looking at what I CAN do. So I bought a pack of A3 foam board sheets and I have started playing... Hopefully, this is going to end up looking a bit like Peter Miller's Rans Chaos, but at 33" span. I'm not too worried about looks, but have borrowed the approximate layout. I have a power train waiting for a model and some 500mAh 3S lipos. It will hopefully give me a 'throw about' model that will be nailed on for next year's spot crashing, sorry landing competition; Fly to height, cut the motor and aim for the flag! So far, I have really enjoyed this process. Learning what can be done and overcoming problems is what makes building fun. And the airframe will cost less than a tenner! Wings and rear section of the fus underway in the pics. Graham

The wing and fin shape looks like one of Keith Humber's designs to me. If it is, it will fly really well...

"You looked younger in the photos" Oh, wrong forum...

Posted by extra slim on 15/10/2020 11:41:58: when chatting engines with club members here in the north.. my favourite phrase is "wouldnt pull the skin off a rice pudding".. any others you guys hear? "Have you thought about on board glow". Usually uttered following sudden reduction in airborne noise...

Love a bit of Engine-chat... I was an active buyer of engines when ASP/ SC were in their infancy. I had great experiences with OS with my 40FP and an old 15Max being superb, reliable motors. As stated before, an Enya SS40 was and still is a gem; powerful, easy to use and reliable. Once SC/ ASP came about, I had a few of these. A very good SC46 that was fine until I stuffed it into some tarmac! I also had an ASP 32 that was rubbish. It never really ran well, and when it did, it had no real power. However, I have an ASP61 from this era that was and is a great engine. Reliable and very powerful. However, for me at the time, Irvines ruled the roost. I favoured small models and had a selection of 20s and 25s; both ringed and ABC. All handled well, were powerful and reliable. Again, I still have most of these. A mention for a little PAW80 I bought partially seized from a local shop for a tenner. I learned to fly with this great little engine in a modified veron cardinal. Great engine until the spray bar vibrated in half mid flight... Graham

I've paid good money to have my Lumbago played havoc with...

Thanks Cliff. Ordered a mount. I have a new biplane with a nice big cockpit. Perfect for the job! Graham

Great video Cliff. Apologies, I am sure you have answered this elsewhere. Can you share details of the camera and mount please? Graham

OK Trevor, that makes sense. Mine does indeed need a bit of handling to rig, but is quick and doesn't need small screws. It goes like this: Fit the top wing by fitting the upper deck section. Secured from inside the lower wing opening with 2 wing bolts push the interplant struts into the slots in the upper wing connect the aileron servo leads, and fix the lower wing with 2 wing bolts. Before they are fully tight, insert the interplant struts into the slots in the lower wing Connect the aileron joiners. Martin, I don't have too many before it all got covered up! You are correct, it fits to the front former with 2 dowels, and bolts from the inside of the wing cavity. Reason for this is to hide the wing bolts and avoid complication of reaching them through sheeted, curved deck. The deck part is a 1/8" ply former up front to provide a solid base for the dowels, with lightply base and lengthways strengtheners. The rearward former is also lightply. I lined the N-Struts against the strengtheners and marked the position and then made a hole in the base to engage the ends of the 'N's. I then clamped and glued them to the lengthways strengtheners and the base holes before adding a strip of 3/16" to the base between the outsides of the 'N's and the edge of the base. This gives extra strength to the Cabanes, and gives me something to secure the end of the sheeting to. I added a former in the middle to support the sheeting, and that was about it. To fit to the wing, the cabanes fit into slots between lightply ribs. I set these during the wing build by using a piece of scarab cabane wood (with the 1/32" ply doublers added for spacing) covered in cling film as a spacer. as a result the fit is a close interference fit, which makes rigging easy. Rigging was dead easy; I clamped the deck to the bench and slotted the wing in. I made some spacers to fit under the wing, and put pins in the centre of the leading and trailing edges. I simply tapped the wing until it was level, and then measured from the leading and trailing edge pins to the bench until I had the required 0degree incidence. Double checked all this, and then again with my engineer's level, and let it all set! These pictures may help. Graham

Morning Trevor, It will work, but does it give you anything? I think you'll still have many of the headaches of a wire cabane structure and all the associated challenges of getting it accurately lined up. I went with a permanently attached top wing, upper deck so I could glue the two together and get it lined up without needing to rely on my dubious bending/ soldering skills! How are you thinking of making and attaching the cabanes? Graham

Good post Ron. I think there is a lot of 'superiority' associated with arguments against foam. I love building, and don't have the facilities to cut foam, so generally build my wings, but I would have NO HESITATION using foam wings, decks or anything else. My Warbirds Replicas Tempest has both foam wings and decks, weighs very little, is straight and true and flies brilliantly. So what's not to like? The inbuilt shock absorbing properties have also meant my undercarriage blocks are still solid after some 'enthusiastic' landings. I shall use whatever is most appropriate to the model and situation at the time! Graham

Dirk, that is quite breathtaking. Fantastic. I'd love to see the ejector seat in action!

Thank you Nigel, that's kind of you to say so. I am preparing a project for a 36" lightweight DR-1. It was thinking about this that led to the cabane idea. I'm going to do similar with the DR-1 but the middle and top wing will be permanently joined. It hopefully will be a lightweight for calm evenings. If it works, I'll share, otherwise I'll keep quiet! Graham

Trevor, I left the bulkhead where it was on the original IC design as it was in a good position to use for the forward dowels. I then used Richard Wills' idea for the motor mount, which is to make a combined battery box/motor mount which fits through a square hole in F1 and F2. This can then be slid back and forth to get a good spinner gap. I made this in 2 pieces so I could mount the battery underneath, and had the option to bring it forward under the motor to help balance. The battery hatch is then underneath, hinged and retained with magnets. I'm happy to turn her over as it means the prop can never accidentally spin up due to the presence of the ground! Graham

Thank you Brian. Note to self: lining up the checks on the ailerons once you have shrunk the wing is, er, challenging... Here's some pictures from various stages of build showing the rough idea of the removable section. If you need anything specific, let me know and I'll take some more. Graham

Hi James, I'm a firm believer in aliphatic resin for balsa and ply. Spread it on, push together and clamp, and wipe off the excess. Super strong and minimal excess weight. It's also not brittle like epoxy can be. If you can, clamp. It reduces the air gap and gives very strong joints. Graham