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View Poll Results: Please help name this glider
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Old Jan 12, 2012, 03:50 PM
Making wood fly since 2007
Windependence's Avatar
USA, MN, Rochester
Joined Mar 2008
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Quote:
Originally Posted by Ray Hayes View Post
How about I send you my 54" free Flight Playboy, it has been fully framed for at least 15-20 years, been dragging it around between two states and three homes.

Let me know ....

Just kidding again ...

Ray
Sky Bench ... Woodys Forever
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Actually Ray the Playboy is on my list. I have plans for the 80 inch version. I also have the plan for the Cleveland Condor. In my not always humble opinion, all of those FF designs of the 30's and 40's are gliders. They were the original ALES planes. 30 second motor run, roughly, and the last one down wins. I also have the plans for the 1948 Petrola Cobra, Kiel Kraft Falcon and some more FF designs. So am I missing something, as I have been looking for older sailplane designs there seems to be a gap during the 50's and 60's. Not too many sailplane designs from that time period. The 70's saw a resurgence of sailplane designs it seems.

Wayne

PS. The playboy is the plane that got me interested in the older "vintage" designs in the first place. If you ever change your mind feel free to send it my direction. I would give it a good home.
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Old Jan 12, 2012, 04:37 PM
Egads! It's a GIRL!
Lil Stinkpot's Avatar
United States, CA, San Jose
Joined Jul 2011
3,285 Posts
It does, doesn't it! A Playboy has been on the list ever since DORY saw one, and really liked it. It's an RC version, and has been AWOL for three weeks after they lost it after a two mile chase. It was thermaling away!
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Old Jan 12, 2012, 05:08 PM
registered weapon
IHAVAWDY's Avatar
United States, MT
Joined Mar 2008
3,218 Posts
If your building classic gull wings, the Slingsby Petrel 13 is my favorite. Beautiful sailplane....Gotta build me one of those.
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Old Jan 12, 2012, 05:16 PM
Making wood fly since 2007
Windependence's Avatar
USA, MN, Rochester
Joined Mar 2008
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Quote:
Originally Posted by IHAVAWDY View Post
If your building classic gull wings, the Slingsby Petrel 13 is my favorite. Beautiful sailplane....Gotta build me one of those.
Yep I've seen the Petrel and it is a gorgeous sailplane, my only issue is that that one does not scale down very well due to those pointy wing tips. 3 meters is about as big as I will ever build and unfortunately many of those great scale gulls don't scale down that well. I can get away with the Moswey because the wings are less tapered. I've seen video of the Petrel in flight and it is a joy to see in the air.

Wayne
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Old Jan 12, 2012, 06:12 PM
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Don Stackhouse's Avatar
United States, OH, Bradford
Joined Jun 2005
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If you have access to some really good low Re airfoil technology, it is possible to get around the pointy tips problem. Our Roadkill Series DC-3 is much smaller than 3 meters, has very pointy tips, and has absolutely impeccable stall behavior. A healthy dose of washout can help, but having a nice variation of airfoil shapes from root to tip is the main part of the solution. BTW, be careful about making the tips thicker than the root, fat airfoils and low Reynolds numbers are a bad combination.
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Old Jan 12, 2012, 06:57 PM
Making wood fly since 2007
Windependence's Avatar
USA, MN, Rochester
Joined Mar 2008
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Hi Don,

I am a lot of things but an aeronautical engineer I am not. Calculating Re's across a wing and optimizing airfoils for different wing sections are tasks best left to smarter people than me. I still have a slot open for the DJ Aerotech skunkworks 3 meter project that goes with that V tail you showed us almost 2 years ago now. Also, how is the 2 meter Chrysalis aileron wing project coming?

Wayne
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Old Jan 12, 2012, 07:11 PM
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United States, OH, Bradford
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My recent nomadic lifestyle has been bad for both of those projects, although I have made some progress. At the moment I'm completely moved out of Saginaw and back in Ohio, but around the end of the month I will be finding and moving to a new place north of Detroit. If anyone knows any clubs or flying fields around there, I'd like to hear about them.

As far as calculating Re's, it's not that hard. Assuming sea level ISA std. day air (which will be close enough for most of us, most of the time, although I did work with a guy once who wanted to build and fly one of our Roadkill Series models in La Paz, Bolivia, at about 12K MSL), the formula is:

Re = 778 * speed in MPH * chord in inches.

Typical HLG's and slower park flyers might typically have Re's around 60K - 100K, larger sailplanes might have root Re's up around 250K or so, higher speed slope soarers and F3B models might see much larger numbers. A typical full-scale sailplane might see numbers from 500K to 1.5 million, a full-scale Cessna might operate around a few million.

As far as stall characteristics, a good strategy is to have the airfoil's high point at the tip a little further forward than at the root, but not too much further. A linear variation from root to tip will usually do OK, although it is possible to get fancier than that. The Chrysalis wing has three different baseline airfoils along the span, with non-linear blending between, and corrections applied to each rib to compensate for covering sag.
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Old Jan 12, 2012, 07:22 PM
ahh crap! crunch..
atmosteve's Avatar
Australia, QLD, Fraser Island
Joined Nov 2007
3,870 Posts
You just have to take one look at that Petrel, apply the good old TLAR priniciples to it in a 2 second abstract mental calculation, and you just know it would be a proper b!tch of a thing to fly if true to scale, or perhaps even if not.
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Old Jan 12, 2012, 07:28 PM
ein flugel schplinterizer
seanpcola's Avatar
USA, FL, Pensacola
Joined Sep 2004
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I'd hate to try to narrow down to one vintage build. I do know I fell in love with the Goldberg Valkyrie that I got to see in person (and happen to have a short kit for ).

That Cobra featured a few pages back haunts me too.
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Old Jan 12, 2012, 07:29 PM
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United States, OH, Bradford
Joined Jun 2005
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Steve, I'd say that the potential for that is certainly there, but if the model designer does even a little of their homework, it could be a pussycat. The Petrel might actually be a good application for a Horten-style bell shaped lift distribution ("BSLD"), which would eliminate adverse yaw, reduce the bending moments on the spar (and therefore the structural weight), and make it essentially immune to tip stall. For more on the BSLD, check out:

www.nurflugel.com.

If you're a real "glutton for mathematical punishment", try the "technical papers" section.

Bill and Bunny Kuhlman have also addressed the BSLD in their "On the Wing" column in RCSD.
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Old Jan 12, 2012, 08:47 PM
Making wood fly since 2007
Windependence's Avatar
USA, MN, Rochester
Joined Mar 2008
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Quote:
Originally Posted by seanpcola View Post
I'd hate to try to narrow down to one vintage build.
Sean, I completely agree. There are so many fantastic old timer designs I don't know that anyone could ever limit themselves to just one. If you have not seen it already, go search for the Valkarie build by FrannieB over in the vintage and old timer thread. It is a work of art.

Wayne
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Old Jan 13, 2012, 01:13 AM
Torn 'twixt buildin' and flyin
TheNightowl's Avatar
United States, TX, Austin
Joined Oct 2007
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Quote:
Originally Posted by seanpcola View Post
I'd hate to try to narrow down to one vintage build.
Can't do it. Especially since I have, for most of my flying life, actually BEEN a freeflighter!

Nightowl
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Old Jan 13, 2012, 05:35 AM
ein flugel schplinterizer
seanpcola's Avatar
USA, FL, Pensacola
Joined Sep 2004
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Yeah, I followed Frannie's Valkyrie build. Roy Walton (God rest his soul ) was about to start on one when his health started to decline quickly. I've got that kit.
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Old Jan 13, 2012, 07:49 AM
Registered User
United States, IN, Fort Wayne
Joined Apr 2003
1,571 Posts
Anyone seen an Imperial RC 100 flying lately ?

This is one is on my vintage kit bucket list, I have the kit, someday.

Ray
Sky Bench ... Woodys Forever
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Old Jan 13, 2012, 10:54 AM
AMA 5285 LSF 8104
Aquila Guy's Avatar
United States, OR, Hood River
Joined Aug 2008
340 Posts
Quote:
Originally Posted by Windependence View Post
Ok, so let's talk about our woodies , alright let me rephrase that. Let's talk about classic wood sailplanes. I think it can safely be said that I am addicted to building and flying sailplanes. My list of "future" builds is so long that I will be dead and buried before I ever get to all the planes on that list. To make things even more problematic I am really taking a liking to older designs from the vintage era of modeling. I understand that the older gliders and FF planes cannot "perform" as well as the new composite planes, but what they lack in performance the more than make up for in style.

My quandary is what planes to build, yes plural, planes. I know I won't ever get to build most of the 300+ plans I currently have on my computer hard drive but I am going to make the best effort I can. I am currently building the 3 meter Raven, a 1986 design gull wing glider. I have a couple of little projects lined up after that but my question is this.

If you were asked which glider or old timer plane was a must have plane, which would it be? Now to be clear here I am asking this in the woodie thread so molded planes need not apply. I have seen some beautiful old timer gliders that I almost feel compelled to build just due to their looks alone. One of those is the Fillon's Champion, a design from 1945. Another is the Moswey III, a scale gull wing design from the 1940's. So tell me what you think of when people mention classic wood gliders.

Wayne
I still have my Aquila I built in 1979, love it! I have NIB an Aquila Grande and Soarcraft Magnum 12. I think the Mirage would be another good addition, possibly the Astro Jeff.

Having just looked at a full size Moswey III, that would be a sweet model. I also worked one day on the only surviving Orlik, which is on my build list. I am also fond of the Petrel and Fafnir. Vintage gliders from this side of the pond, I would love to build either of Hawley Bowlus's designs: the Paperwing Albatross (the rotating tip ailerons would be a %#$%&), and the Baby Albatross.

As many have said on this forum: so many sailplanes, so little time....

Scott
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