When does a loosely copied design become your own????? - Page 3 - RC Groups
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Nov 19, 2010, 11:31 AM
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Evan D's Avatar
Rick, how big is the big one going to be and what will you power her with?
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Nov 19, 2010, 11:57 AM
Scott R/C Time Pilot
orange&white's Avatar
Originally Posted by CashRC
That's what I'm afraid of, I desperately want to start my Playboy, but I have a little Powerhouse on the bench now, and I know me..If I don't finish it, I never will...
But then again..It's MY hobby isnt it..not like it's work, I don't have a set schedule or plan or number of items I MUST finish. That might be my problem..I tend to go about this like I'm at work. I mean I LOVE to build, but I get to a point sometimes where I have a bird partially done, and something else catches my eye, but I stay on the straight and narrow and finish what I've started...what do you guys think?

I still have unfinished models on the bench after 17 years, but they will be done some day

Nov 19, 2010, 03:25 PM
Registered User
The big one will be 9 foot span x 18" chord. The fus skeleton is 80" long.
Power will be provided by Saito FG20 fourstroke gasser (which i have but not run yet).

interesting features include removable u/c, removable aft fus/tail feathers, removable outer wing panels, LE slats and more (all to be covered in the build thread).

This big bird is a much much modded variant of a Red Zephyr - but I'm re-naming her to the 'Mistress Misty' since she is just far too different to the original Herb Greenberg design to be called anything like a Red zephyr. In fact, it would most likely outrage SAM afficianados if i were to claim that this version of mine was just a big Red Zephyr, since practically every proportion, internal and external, has been significantly changed. The way i like to think of it is - the Red Zephyr gave me the inspiration and the desire.

Remember there's no 'plan' for this model other than the experience of my previous two and unique RZ variants so much of her construction and technical solutions are kinda invented as i go........

Therefore look out for the "MISTRESS MISTY" build thread - it'll be fun to be sure.
Nov 28, 2010, 10:59 PM
MAAC 6251
Originally Posted by Rick.
Why do i ask, well, i kinda touched on this a while ago, but lets say you take a well known model design. increase the chord say 10%, then maybe shorten the moment by 20%, and while your at it chop a bit off the nose too. slightly re profile the tail feathers, give it a new airfoil section, leading edge slats,and a 'fatter' look by widening the fus 15%. Use many of your own pet construction features (wing fixing, spar layout, tail structure etc) and finally, for good measure make the whole thing 50% bigger. Now, it still kinda looks LIKE the original design, but everything is modified significantly - so, can you now call it your own design - or at least be justified in giving the changling a new name?????

How do you feel about that? cos thats what i have done to the Red Zephyr design and i don't know whether to feel embarassed with my butchery or smug and pleased that i've produced a new creation.

Question is, is it now MY design, needing a new name? or just a (heavily) modified Red Zephyr??????????? wrestling with my conscience here........

Oh, in case you're wondering whats NOT been touched, well I think the undercarriage is close to original spec - apart from the 50% increase and the windows are unchanged (though most folks do em differently anyhow).
I always look at it this way. The point where I've changed enough of the design that I can no longer blame the original designer if it flies poorly is the same point at which it becomes my design.
Dec 01, 2010, 04:19 PM
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Lol - thanks Rob - i guess your saying when you can't blame the original design, yours ain't the original design.

Well, apart from the fact that i've changed everything, my RZ variant still looks LIKE a Red Zephyr - but this is because the original RZ design has a few very strong signature features that will always remind you of the RZ wherever they crop up. I mean - just look at that dihedraled wing - only a handful of planes have anything resembling that shape (the Lanzo Bomber being one). The only thing i never liked about the original RZ was that oversize bulbous Fin - I'm correcting that on my new build, along with a completly redesigned tailplane.

Looking at the thread above this one, Bill has a lovely old SOY design 66" RZ and looking at that it seems very long and slim compared to my variants plus its nice and floaty, mine are somewhat more robust and rather heavier.
My all red version is 72" and 6 pounds with slats and flaps.
My red and white is 36" and 13 oz with a small electric outrunner
Both fly really well, thankfully.
Dec 01, 2010, 04:56 PM
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owlsabie's Avatar
Hey there Rick - I've never really understood slats. Do they make much difference? I gather they've got something to do with the boundry layer and things?
Dec 01, 2010, 05:25 PM
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Owlsabie - I like to take the simple approach to aerodynamics and think of it like this - when the wing approaches the stall angle of an unslatted wing - the wing with slats has the airflow both funnelled in a little, therefore speeded up, AND physically redirected a little to follow the contour of the wing. The result is the slatted wing will remain unstalled for an extra few degrees of angle of attack, producing useful lift, beyond the point that it would have normally dropped out of the sky. If used only on the outer portion of the span, the slats will prevent the wing tips from stalling untill well after the centre section has stalled and the planes will has started recovering airspeed. No tip stalling is very useful if you like turning tight n'slow near the ground!!!! However, personally, i prefere FULL span slats for maximum slow flight effect. And yes, they are very effective and do not affect flight trim, they do add a bit of drag though - AND depending on the design and slat gap, can make lots of wonderful wooshing and whistling noises during a dive
Dec 01, 2010, 07:16 PM
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Outboard they sure do help in short field landing. I used them on my 7 foot Sal Taibi Power House and wouldn't want to be without 'em.

I recently found a good Red Zephyr 3View and am drawing the plans now. Outboard wing slots will likely be included.
Dec 01, 2010, 08:32 PM
MAAC 6251
I think you have changed the design enough to call it The Rick Zephyr, if you want to.
Dec 02, 2010, 03:07 AM
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owlsabie's Avatar
Thanks Rick! Now I know, and might have to try them on my next plane

Dec 02, 2010, 08:45 AM
MAAC 6251
The slat speeds up the sir flow and helps keep it attached to the surface of the wing when it otherwise would separate and cause a stall. Great also for short take offs. I have seen this Lysander fly several times and it takes off with a very short roll and at a very slow speed.
Slat is the name of the device, slot is just the gab it creates between it and the wing. Many confuse the two.
Dec 02, 2010, 11:41 AM
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Gents, if it helps, think of slats as like those little spoilers that keep the crud off the back window of a station wagon or hatchback. And Rick, if you put slats on your plane, wouldn't it be a Red Lysander?!
Dec 02, 2010, 12:22 PM
Registered User
Slots are the fixed blades on the leading edge of a wing as in the Feisler storch, Slats are the adjustable blades.

Regards Ian.
Dec 02, 2010, 12:59 PM
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I got my idea for wing slots on the Power House from an old Air Trails magazine. It took a little work but was well worth it. If I can find the magazine the article can be scanned & posted if anyone is interested.
Dec 02, 2010, 01:39 PM
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owlsabie's Avatar
Jim - I would be interested.


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