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Old May 26, 2012, 09:10 AM
RFJ
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(BTW Ray, memory going there - the Scamp was 5x not 3x!)
Your not wrong George. Isn't getting old a wonderful thing Perfect memories of happenings fifty years ago but can't remember things from a couple of months back.

Dereck. For what it's worth I consider undercamber the work of the devil (oh dear... not a wise thing to say on a vintage forum) so I know what I would do with the section if I was building a JJ60. Like you I have never yet built a model to someone else's design where I haven't changed something. Usually quite a few somethings.

Ray
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Old May 26, 2012, 09:53 AM
I like real wooden aeroplanes!
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Your not wrong George. Isn't getting old a wonderful thing Perfect memories of happenings fifty years ago but can't remember things from a couple of months back.

Dereck. For what it's worth I consider undercamber the work of the devil (oh dear... not a wise thing to say on a vintage forum) so I know what I would do with the section if I was building a JJ60. Like you I have never yet built a model to someone else's design where I haven't changed something. Usually quite a few somethings.

Ray
Yes, I used to have a memory, now I have a forgetory! About undercamber. Funnily enough Ray I might well have agreed with you but I have changed my mind slightly of late. Why? Well, the two models I have built in the last year with the original undercambered sections, the KK Bantam and the Frog Witch II, are two of the nicest flying models I have ever owned. They are very good at normal flying speed, don't seem to have any penetration worries but where they really shine is in having truly delightful handling at ludicrously slow flying speeds. Whilst agreeing that this happy state of affairs may be due to lots of other factors, I am content that the wing sections are certainly playing their part.

So I would have to disagree with you here, IMO, Dereck, keep the wing section, it is part of the character of the J60.
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Old May 26, 2012, 10:21 AM
RFJ
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I remember years ago reading in Aeromodeller a very learned article complete with all the usual graphs, formulas and hieroglyphics which proved conclusively that flat bottom sections were superior in every way to undercambered ones.

Several months later an equally learned article appeared which proved, equally conclusively, the exact opposite.

"Chacun a son gout" as we say in Norn Iron.

Ray
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Old May 26, 2012, 11:22 AM
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George, Do you get the impression that Ray was taught French by Tommy Makem?
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Old May 26, 2012, 11:32 AM
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:

Tommy tried his best but it's just that on my keyboard I don't have any of those squiggly things and pointy bits for under and over the letters.

Ray
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Old May 26, 2012, 04:33 PM
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Apologies Ray, you're right of course.
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Old May 26, 2012, 08:00 PM
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Hi Dereck, I have a Majestic Major with the standard Junior 60 undercambered wing and it flies every bit as well as everyone says they do.
I'm not sure how much of that is due to undercamber and how much is just low wing loading, but slow speed handling is amazing.
Does the slowest "only just over the top" loops I have seen.
The only thing I would do if I were to build another (and I am thinking of a bigger one) is to change the wing-tail decalage.
My MM flies around at low throttle with about 3/8" of down elevator and high throttle requires 3/4".
I already have about 3 degrees downthrust and could not easily get more, so I mixed down elevator with throttle. This works fine, but does ballon a bit if I throttle down too quickly.
I would probably drop the wing incidence a bit.

Somethung I did consider for the Britkit was an almost double size Junior 60, as I blew up the MM plans another 25% a few years ago. I have a Saito 170 triple which would be ideal and would spend most of it's time about 1/4 throttle which is where it sounds best.
Laid the plans out again last night on the table tennis table (yes it is about that size) - it's still very tempting...
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Old May 27, 2012, 12:33 AM
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Interesting stuff on the undercambered section biz indeed. That and the wing-tail decalage, I've seen plenty about to suggest that they work better on FF models, which fly in steady states, turning at a constant trimmed-in rate and at two power settings of on or off.

Yes, this idyllic state may be preceded by an exciting spell involving such as trimming flights and various degrees of repair up to making a second straighter version

Whereas RC flight involves someone of possibly dubious skill constantly interfering with direction and speed...

Thus am more likely to stick with the wing section for nostalgia reasons, but do wonder about the high decalage. Shuffling the Fuselage top longeron wing seat area is not thar much really.

My lightest wing loading RC model was a twice full size rubber model. I did something fairly unprintable to the prototype's wing section to deal with mine's ability to vary speed some. Not only did it creep around the sky on very low power, but had no bad pitch tendencies with power changes.

There's good reason I seldom do other folks' designs...

D
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Old May 30, 2012, 12:21 AM
I like real wooden aeroplanes!
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Progress Report

End of the first month of the eight month build off and news is that today (May 30th) kkphantom is planning to test fly his Gipsy this evening and has already selected another subject, the delightful Veron Tipsy Nipper.

RFJ's Veron Phoenix is progressing rapidly and RAF_BOB is well into his electrified KK Senator. My own scaled up KK Sportster has a near completed airframe, but I am a bit distracted at present by my knee problems, seeing the specialist in Limoges later today and expecting him to recommend a knee replacement which will clobber the flying for the summer but looking on the bright side might mean more time at the building board!

Come on the rest of you guys - could do with seeing some more build logs started - and....Dereck, have you made your mind up about the 4/5th Junior 60 yet?
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Old May 30, 2012, 01:43 AM
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George, Sorry about your knee problem, but here's a comment that may make you smile, and that I've been hesitating to post for several weeks, but it's true...
As you know, I still try to fly all disciplines: smallish FF, occasional CL and easy radio assist... When you started your Witch, in the Frog BO, I thought "Yippee, George is building a (real) rubber model"... Then a couple of weeks ago, when Raf_Bob started his Senator, it never occurred to me for one moment that it might not be rubber powered FF! I'm starting to think that I'm too pure and naive for all this...
Brian
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Old May 30, 2012, 05:18 AM
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George; My neighbour has just had a knee replacement, I couldn't believe it, a week later he is walking out to the letterbox with hardly a limp, If you need a replacement hope yours goes this well. I am enjoying watching all the "brit" models being built, started my model building on kits like this, brings back lots of memories.

Colin.
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Old May 30, 2012, 05:57 AM
I like real wooden aeroplanes!
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Well, I'll accept the naive bit Brian, but pure...!!!???

The fact of the matter is that, with the wonderful inexpensive micro outrunner motors now available, and small, light lipos, many rubber models make great electric R/C conversions, either in their original size like the Witch or as scale-ups like my Tom Tit and Mamba. These models look great in the air, and the Witch (whose structure, apart from the necessary control surfaces and motor mount mods, is exactly "as per") can be made to fly just like the rubber powered original, but for longer and without the subsequent cross-country running and tree-climbing! The longer nose of the average rubber job is almost a guarantee against the tail heavy problems which are common when electrifying vintage power models due to the equivalent power electric motors being much lighter than the IC lumps they replace and lack of space in the short noses to get the battery far enough forward to offset this.

Just to make you tear your hair out even more, if I can ever find the time I would love to produce an electric R/C version of either Copland's GB3 or Stoffel's Aristocrat, or maybe the same designer's '49 Flight Cup winner. I just love the looks of these classic models, but if I built a rubber powered F/F version, I would rarely if ever get the chance to fly it, certainly not to anywhere near it's full potential.
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Old May 30, 2012, 06:01 AM
I like real wooden aeroplanes!
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Originally Posted by ColinNZ View Post
George; My neighbour has just had a knee replacement, I couldn't believe it, a week later he is walking out to the letterbox with hardly a limp, If you need a replacement hope yours goes this well. I am enjoying watching all the "brit" models being built, started my model building on kits like this, brings back lots of memories.

Colin.
Thanks for the encouraging words Colin. No-one wants to volunteer for surgery, but at present the knee is having just too negative effect on my quality of life (and my flying!) so something has to be done. Glad you are enjoying the build off, I hope there might be quite a few more people join in over the next few months.
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Old May 30, 2012, 06:07 AM
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when Raf_Bob started his Senator, it never occurred to me for one moment that it might not be rubber powered FF! I'm starting to think that I'm too pure and naive for all this...
Brian
Brian, I would love to fly free flight, especially rubber, but two problems present themselves 1) Where? I don't have access to a suitable area unless I travel many miles. 2) I'm too old and decrepit!! There's no way I could chase after them. I get breathless walking downhill never mind up (this is not a joke) and as for running......... So electrocuting such models brings the within my reach (just). A Senator with a silly little prop buzzing around a ridiculous speeds does spoil the feel somewhat but it's that or nothing. Or just stick with slope soaring which is what I've done for many years. It's great to go back to building a small lightweight model but I 've forgotten how to build light! I need to stock up on some decent balsa since I'm building the Senator from stuff I have on hand and which was never bought for such a use. I'll see how it turns out and proceed from there.
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Old May 30, 2012, 07:22 AM
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George, if you manage to find a GB3 plan, please let me know!!!
For Bob and George, I understand your points of view. I have room to fly FF (just), about 20 km away, and the whole thing is eased by the fact that I only fly on nice days (i.e. no long walks and my FF and radio assist models can be really light). If I want to fly and there's more than a very light breeze, then it's CL
If I can become a competent enough RC pilot, then I shall be able to fly Tomboy type models only a couple of hundred metres from the house but, at the moment, I'm limited to J60, MM or Simplex, etc.
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