Nigel R

I use a set of fittings similar to those PDB posted.

My 4 button imaxB6 clone came with an adaptor lead that fits a clip-on glow starter. Maybe you also have one already, still hiding in the box for a charger?

4 cell Eneloopp nimh for all my IC airframes. Quality cells, technically simple answer, right volts for my JR servos, pack weight is not an issue at .40 size glow and upward. I use a simple trickle charger. 2 cell lipo would also work if you are kitting out with new servos that cope with the voltage.

The SF do also have plating issues. Buyer beware, etc. I have several 61 SF bought from second hand sources that had peeled liners. I read that Nickel plating requires a higher degree of both workshop cleanliness and chemical bath purity and OS struggled with that. The other manufacturers were not restricted by tighter environmental laws regarding chrome. Of course OS did also use ringed pistons, I guess that wasn't fashionable, very few second hand engines have ringed setups. I do have a ringed SF, they are out there, and it runs just the same as the ABC one. The heli engines are a reasonable source of ringed piston/liner combos, if needed.

Keep your eyes peeled for a nice 61SF on ebay, would be my suggestion. They are, as you noted, very nice.

Hmm. Sukhoi, whatever flavour, will fly at Reynolds far above what a Wot 4 does, apples and orange etc. One thing Chris Foss was good at was marketing and protecting his IP. Pinch of salt etc. What did this testing consist of? What results are there? What controls were in place to ensure single changes were tested and measured? I remain unconvinced that he simply didn't draw something round a handy curve and claim it was the best thing since sliced bread...

I believe the glider guys are way ahead there Peter, see work by Drela and previously Selig for instance. With a power aircraft we completely swamp any differences in performance with excess power.

I'd love to see Chris Foss' supporting data for this claim...

Faced with the prospect of cutting all those ribs, I returned to the tailplane and instead cut and shaped and tapered the elevator. This was then hinged and bevelled. Whilst I still have some shaping of the fins and rudders to do I think I am almost out of excuses to avoid cutting the wing ribs. As usual for me, the elevator has harder wood at the hinge line and a hard point to take the screw on control horn. The rear of the elevator is simply soft sheet.

You could take the 4-max setup from the Sky 40 and use that, it's a very similar size/weight trainer airframe. https://www.4-max.co.uk/tn-sky40.htm

Can't help but think the right answer is "5 Laser 80 cylinders fitted to the ASP crankcase which might as well be replaced because the valve gear is different which sort of gives you a five cylinder Laser"...? 😈

welcome aboard!

Answering the exam question, no, I don't think most people push themselves outside their comfort zone very often, if at all. I would disagree, with the caveat - simulator hours are definitely worth something - but not as much as the real thing.

Thanks Nick. It's a touch tight, I'm aiming to open up the slot a little, later on. As you can see I'm going to have to be really careful to get the hinges lined up when it comes time to glue them. The cocktail sticks are an aid to keeping things nicely aligned and might do double duty as slight reinforcement to the joint. External fairing - hadn't thought about it yet, but it's a good idea.

I got a few shots of the rudder assembly to better show the thing moving around

K+S do thin wall brass tube in short lengths, if you need to sleeve the wheels. A single torque rod on each wing is my method. As per original Chilli Breeze plan https://outerzone.co.uk/plan_details.asp?ID=13801 Your test stand is too complicated 😄 Mine just have the engine screwed direct to a piece of thick ply!

That could work (and yes, the nacelles will go back to the main spar). That said, I'll also be running some thin glass right out past the nacelles this time - I'm hoping that, coupled with the half ribs, will be enough to toughen up the LE root area

Swap it out for the Irvine 46, quick!

Good point, and easy to check.

Agree, 1/8" or 10g would be plenty. I'd use a wing mounted U/C though - just personal preference.

Enya 50 comes with the caveat that the older silencer may not be as quiet as the others. But, any of your 2 strokes would do the job I think.

Indeed it will be 😄 The wiing section is fully symmetrical though. I've used a NACA four digit. I see that I forgot to mention, I am making the wing fairly thick near the root (17% IIRC) to help with strength and to hide the retracts. This tapers down to 12% at the tip. Another point I did not mention, I have placed several half ribs near the root and around the nacelle. With Double Trouble, I found I naturally wanted to hold the airframe at the root of the wing, and without some reinforcement the 1/16 wing skin is, erm, "delicate", hence adding half ribs for extra support in that exact spot.

With a lot of cutting out by knife, and careful sanding... slow going! Nevertheless, that method is the quickest route I have to getting an accurate set of ribs when the wing is tapered (I don't like the sandwich method). (I haven't yet ventured into printing templates or getting ribs CNC'd or lasered) With a simpler rectangular planform, I'd (a) likely use foamboard these days, and (b) cut a lite ply template and then cut directly around that - which is dead quick and easy with foamboard ribs.

If the engine could use a new ring, its probably worth doing that fix anyway. On the % nitro question, I can only say that I have several OS 4 strokes that run perfectly on 5%.

Boca are US based, be warned. There are plenty of UK suppliers which will work out far cheaper.