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Old Oct 15, 2012, 07:07 AM
So I'M meant to be in control?
Colonel Blink's Avatar
Ilkley, West Yorkshire, UK
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Originally Posted by mixer421 View Post
Thanks to all for the encouragement and I will surely take advantage of the offers of help and advice. I have built many models over the last 60 odd years but of late have been tempted along the path of the, probably unmentionable on here, electric foam devices. Rather busy with household projects devised by Mrs Mixer at the moment but a bit of balsa bashing will be an exciting Winter project. One of my favourite Keil Kraft models was the Dolphin glider, perhaps an electric version (Pylon mounted?) could be quite an unusual challenge!
Mike - just in case you haven't seen, here's a .pdf of the Dolphin plan:
http://www.rcgroups.com/forums/showp...ostcount=4712;
though it is on Outerzone too. When I looked to make a pylon for the Middle Phase (which I still must get around to one day!), research seemed to imply that the thrustline should go through the approximate centre of the tailplane. Given how much higher than the t/p the wing seat is on the Dolphin, that'll make for significant upthrust!!

It's a pity that 'Da Management' has you busy with houshold duties, as the Dolphin would qualify for this year's Britkit Build Off which ends on the 31st Dec; Jan 1st heralds the start of the 2013 Brit Plan Build Off (ie Vintage models built from plans published in British magazines up to the end of 1969). Having said that, if you want to build the Dolphin, you do it - I for one would be an early subscriber to the build thread!!!
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Old Oct 15, 2012, 07:37 AM
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Originally Posted by Colonel Blink View Post
Jan 1st heralds the start of the 2013 Brit Plan Build Off (ie Vintage models built from plans published in British magazines up to the end of 1969).
Is that cut-off date confirmed?
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Old Oct 15, 2012, 07:45 AM
So I'M meant to be in control?
Colonel Blink's Avatar
Ilkley, West Yorkshire, UK
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Probably not. But it'll be sometime around then! So I won't be able to build my 1978 Jack Headley Piper Cub....
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Old Oct 15, 2012, 07:58 AM
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Originally Posted by Colonel Blink View Post
Probably not. But it'll be sometime around then! So I won't be able to build my 1978 Jack Headley Piper Cub....
Nor I my 1973 STOL
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Old Oct 15, 2012, 08:40 AM
I like real wooden aeroplanes!
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South-west France
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Sounds like just a bit more down and side thrust will get it just right Colonel.

Re cut-off date for the proposed Britplan build off. No way do I want to be a dictator here, it is just that when I floated the idea there seemed to be an equal number of responses wanting an earlier date and a later date! So, what I propose to do, nearer the time, is canvass views on what the date should be and then post a poll listing all the suggested dates and we will do the democratic thing and go with the majority vote. I know that it will be sad if someone's favourite falls outside the date, some of mine probably will, but it is the only fair way I can think of to do it - unless someone can suggest a better way??

Re the KK Dolphin. Another design by the immortal Albert E Hatfull. In the original size, with a pylon mounted motor, it would be "challanging" I think. May I suggest a look at the KK Orion rubber model, maybe scaled up to "Ajax" size, which offers a lot of the same charms and probably an easier conversion with more chance of success?
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Old Oct 15, 2012, 10:07 AM
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> to the end of 1969

Surely the accepted cutoff date for Vintage is 1950?

I once built an 'Orion' in its 'proper' form and it was not what one would term a good flying machine and was subsequently scrapped rather than have more time wasted upon it.
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Old Oct 15, 2012, 10:15 AM
Since 1952
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Canada, AB, Edmonton
Joined Oct 2004
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Quote:
...full throttle makes it pitch up to an unsustainable climb angle
Have you tried mixing in down elevator with throttle?

Some will say that's "cheating" and I suppose it is in a way, but I've found it to be a great help on every one of my old timer type models. You can of course manually feed in down elevator (as you've probably been doing) but we might as well take advantage of available technology.

Very easy to do, and well worth trying once you've completed all your other adjustments.
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Old Oct 15, 2012, 12:09 PM
I like real wooden aeroplanes!
Sundancer's Avatar
South-west France
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Originally Posted by Applehoney View Post
> to the end of 1969

Surely the accepted cutoff date for Vintage is 1950?

I once built an 'Orion' in its 'proper' form and it was not what one would term a good flying machine and was subsequently scrapped rather than waste more time upon it.
Yes indeed Jim, it is 1950; however, what I tried to do with the Frog and Britkit build offs was to encourage people to build models they either had fond memories of or models they had always fancied as youngsters but never built, often due to reasons of cost. Since the end of the fifties is now 52 years ago, obviously a lot of peoples modelling memories were going to date from that period, not necessarily from the forties or earlier, and as there were a heck of a lot of kits first produced in the fifties (for example the Frog Senior series and the Mercury Starflites), the 1950 cut-off date would have been somewhat restrictive. Same logic applies to plans, very many of the classics - Tomboy, Paageboy, Madcap and many more date from the fifties, my preferred date would be the end of 1959 or 1960. However, to the generation somewhat younger, there were a lot of classics also published in the sixties, so I wouldn't be opposed to it being 1969. So I'm quite happy to go with what the majority want - just as long as there are lots of nice models built and people enjoy themselves.

I just think the KK Orion has a slightly off-beat appeal about it. I'm quite prepared to believe that it might not be a great performer in it's original form - but then, how many 20 inch beginners rubber models are? - but I'm also prepared to bet it could be an excellent flier either original size or scaled up with an electric motor, either F/F or R/C
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Old Oct 15, 2012, 12:51 PM
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Good thinking, George. I was in at the start of the Vintage movement in Blighty, when South Bristol, Croydon and the Northern Area were about the only ones then concerned with the new class and common rules were agreed - so I still think '1950' ... but there are likely far more people now whose memories and interests don't go back, or far into, that pre-51 period.

The corresponding USA Oldtimer - 1942 cutoff - was been since followed by Nostalgia classes ... 1943-1956 to take care of the same situation.

For a good 20" model the Veron 'Goblin' excells - great little performer which looks like a period Wakefield when up above.
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Old Oct 15, 2012, 01:52 PM
So I'M meant to be in control?
Colonel Blink's Avatar
Ilkley, West Yorkshire, UK
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And that's it in a nutshell - I would have been much less likely to have got involved if it had been fanfared with a pre 1950 cutoff date.

Having said that, the Ajax is a 1939 (original) design and the Gypsy is 1949....!
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Old Oct 17, 2012, 05:29 AM
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United Kingdom, England, Kent
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Thanks for all the advice and comments.
I'm still undecided and though there are several designs - I really like the 'Competitor' - I'm still very tempted to try the Dolphin, mainly, I suspect, for nostalgic reasons - it was the first model I built unaided by Dad. I know it's risky but I'm accustomed to watching weeks of work crash, it's all part of the fun!
I've made some provisional mods to the plan. I,ve changed the angle of the front bulkhead to get a better thrust line through the estimated centre of mass / drag. The rudder / elevator wasn't easy but the picture shows a possible solution.
I don't want to hijack the Colonel's thread and will start my own build log but thought I'd get the comments from the experts first.
Mike.
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Old Oct 17, 2012, 07:13 AM
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I see no reason for this not to work ok. The unusual fuselage shape can muddy the picture a bit
but it's the wing/tailplane relationship that really matters. Perhaps reduce wing incidence a bit to
help control ballooning under power. But with radio you always have control anyway. Following advice I received from George I reckon your elevator and rudder areas could be reduced somewhat. If you have dual rates you've the best of both worlds. Give it a try. Even if crashes in flames (which it won't) it's not so much to lose!
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Old Oct 17, 2012, 09:54 AM
I like real wooden aeroplanes!
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South-west France
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Yes, go for it Mike! My main reservation was with using a power pod, with a nose mounted motor it should be OK, providing you can keep it light enough. Maybe the rudder you have drawn in is a bit on the - er - generous side and I would think one half of the elevator would be plenty. I think I would also like to make the wing mount a better fit to the wing section, I must say this is an area - strapping undercambered wings onto flat mounts - where Albert seemed to be a bit cavalier, see HarryD's build log for the Dandy and mine for the Bantam (built for the 2011 main build off).

So....is it going to be a Britkit Build Off entry - still 2.1/2 months to go so plenty of time!? If so let me know and I will post a link to your build log here http://www.rcgroups.com/forums/showthread.php?t=1644819
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Old Oct 17, 2012, 01:42 PM
Agricultural flyer
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United Kingdom, England, Kent
Joined Aug 2007
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Having read a bit more of the Colonels blog, I'm a little more confident also helped by the comments from Sundancer and Bob. Reducing the rudder area will make the elevator a bit easier and I certainly hadn't thought about the half width solution. There's still a lot more to work out and I'm sure that reading more build logs will help tremendously.
I'll hold off my Britkit entry until I'm a little further on with the planning. and I am a slow builder!
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Old Oct 17, 2012, 04:58 PM
So I'M meant to be in control?
Colonel Blink's Avatar
Ilkley, West Yorkshire, UK
Joined Nov 2008
3,551 Posts
Quote:
Originally Posted by mixer421 View Post
I'll hold off my Britkit entry until I'm a little further on with the planning. and I am a slow builder!
Mike: If it turns out that you'll miss the cutoff date for the Britkit build off, don't let that stop you from making the DolphinE. I have always been convinced that you need a 'buzz' to build a model and it seems that's what you get from the Dolphin. I for one will follow with interest!!
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