SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Dec 26, 2012, 01:11 AM
less is more
Knoll53's Avatar
United States, CA, Marina
Joined Sep 2006
2,815 Posts
Discussion
Plank DS

The split rudder discussion got me thinking of a heavy little ship that might need some help slowing down for landing. At 232 sq. in. and 5 servos it should be easy enough to make it fast with just a little ballast. Always wanted the pilot above the wing. This ship may be it.

50" wing span

Kent
Knoll53 is offline Find More Posts by Knoll53
RCG Plus Member
Latest blog entry: Air Plank and the Hawk
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 26, 2012, 01:49 AM
I don't like your altitude
Stupot46's Avatar
Joined Sep 2011
3,251 Posts
Nice.That side view reminded me of the Horten with the cockpit in the fin(XIII?)
Looking at the split fin,when I was playing about with the idea,it crossed my mind they could be opened by an internal drive,a rotating T bar at 90* to the hinge line.Torsion spring to close.Looks as though you have the space,though the hinge line may discount the idea.(I'm presuming it isn't a functioning rudder)
Stuart
Stupot46 is offline Find More Posts by Stupot46
Reply With Quote
Old Dec 26, 2012, 09:50 AM
less is more
Knoll53's Avatar
United States, CA, Marina
Joined Sep 2006
2,815 Posts
Right! The cockpit in the fin has been done before and in this case is driven by the needed to have the fin above the AC, to comply with the Killer Plank Airbrake scheme. Maybe more sweep on the hinge is needed.

The T-bar sounds workable and easy. Spring closure of the surfaces would be ease as well. I wonder if the surfaces would vibrate or get sucked open at very high speed? I know that if you have a lot of slop in an aileron, it can vibrate wildly at high speed. Conventional horns on each surface would surely work.

The cockpit makes the fin very thick, which is handy for installation of most any linkage system. Possibly internal horns would work.

Yes it's just a split fin. No rudder needed on this little speed demon. Without a fuse and with very little sweep, it will require loads of lead in the nose, which will make it heavy. Heavy = fast. A ballast compartment between the nose and the cockpit will boost up speeds for when the winds pick up.

Although I've been poking around looking for a dynamic soaring site I haven't managed to get in even one legitimate DS loop yet....so this will be a front-side ship for the big wind days.

Kent
Knoll53 is offline Find More Posts by Knoll53
RCG Plus Member
Latest blog entry: Air Plank and the Hawk
Reply With Quote
Old Dec 26, 2012, 10:46 AM
Just call me crash for short
Quick61's Avatar
United States, OH, The Plains
Joined Jan 2011
1,685 Posts
Quote:
Originally Posted by Knoll53 View Post
>snip<

Although I've been poking around looking for a dynamic soaring site I haven't managed to get in even one legitimate DS loop yet....so this will be a front-side ship for the big wind days.

Kent
Maybe this might help - http://www.tuffplanes.com/Flying/Fly...tle_Ridge.html
Or this - http://www.hobiehawk.com/flsmwind.html

I've read more than one place that these slope / DS guys will drive 4-5 hrs to get to a good site.

Mark
Quick61 is online now Find More Posts by Quick61
Reply With Quote
Old Dec 26, 2012, 12:08 PM
less is more
Knoll53's Avatar
United States, CA, Marina
Joined Sep 2006
2,815 Posts
Yes, some will fly across the globe to fly DS. I understand that it can be quite the addiction. I've dedicated my DS site search to absolutely anywhere within 20 minutes of my home. There actually might be a good site at the local state park if I'm willing to go cross country.....could happen.

Round 2 of fin design.

Kent
Knoll53 is offline Find More Posts by Knoll53
RCG Plus Member
Latest blog entry: Air Plank and the Hawk
Reply With Quote
Old Dec 26, 2012, 02:46 PM
I don't like your altitude
Stupot46's Avatar
Joined Sep 2011
3,251 Posts
Looking good.( please exit through the doors at the rear of the plane)
I like the streamlining.

Could you use a push rod and a scissors type arrangement on the fin.Would that work on an angled hinge ?
Stupot46 is offline Find More Posts by Stupot46
Last edited by Stupot46; Dec 26, 2012 at 02:51 PM. Reason: Addition
Reply With Quote
Old Dec 26, 2012, 04:58 PM
less is more
Knoll53's Avatar
United States, CA, Marina
Joined Sep 2006
2,815 Posts
It might be fun to place a small video camera inside the cockpit just to hear the split rudder noise. Don't know if it would be a roar or a buffeting.

Scissors type?
Conventional horn and pushrod will work fine with the swept hinge line if a ball link is used.

Kent
Knoll53 is offline Find More Posts by Knoll53
RCG Plus Member
Latest blog entry: Air Plank and the Hawk
Reply With Quote
Old Dec 28, 2012, 02:56 PM
less is more
Knoll53's Avatar
United States, CA, Marina
Joined Sep 2006
2,815 Posts
Modified the canopy to a simple bent plate.

Looks like this one will come in at 22oz => 13 oz/s.f. wing loading
with ballast it's 24 oz./s.f. (71 gm/dm)
Should move out nicely...even with the big thick (15%) fin/pod.

Haven't decided if I need the lower fuse/skid area at all. I certainly would like to get rid of the drag. Landing on a solid sheeted foam wing will be no problem. Only thought being that the flaps may need some protection during a crow landing. Maybe a little sub-fin would do.

Kent
Knoll53 is offline Find More Posts by Knoll53
RCG Plus Member
Latest blog entry: Air Plank and the Hawk
Reply With Quote
Old Dec 30, 2012, 10:35 AM
less is more
Knoll53's Avatar
United States, CA, Marina
Joined Sep 2006
2,815 Posts
Especially for a little wing like this, a quick, simple and inexpensive building method is part of the attraction. Sig Rhino Hide looks like it might fill the bill for a wing covering and structure. It is a wood product and when bonded to the foam with PU glue, it creates a stressed skin panel that is stiff and strong. From a structural point of view, the Rhino Hide might be the perfect companion to the foam. Would this wing be ready for a 200 mph DS loop? Probably not, but any frontside flying should be good.

This mock up had the skins vacuum bagged on to the foam with PU glue, then a balsa LE added with PU glue.

Kent
Knoll53 is offline Find More Posts by Knoll53
RCG Plus Member
Last edited by Knoll53; Dec 30, 2012 at 10:41 AM.
Reply With Quote
Old Dec 30, 2012, 11:50 AM
I don't like your altitude
Stupot46's Avatar
Joined Sep 2011
3,251 Posts
That's interesting.Hope it works out ok for you.What's the weight like compared to 1/64 ply?
It says not to use water based glue,I presume it will swell.I wonder if it will 'mould' with ammonia.
Stuart
Stupot46 is offline Find More Posts by Stupot46
Reply With Quote
Old Dec 30, 2012, 01:19 PM
less is more
Knoll53's Avatar
United States, CA, Marina
Joined Sep 2006
2,815 Posts
Don't know about the weight. Could be slightly heavier than plywood. Because it is a pressed wood product, it MAY be form-able to even compound curves with enough ammonia. I have no need to bend it beyond a simple curve.....which is easy with the vacuum bag.

Kent
Knoll53 is offline Find More Posts by Knoll53
RCG Plus Member
Latest blog entry: Air Plank and the Hawk
Reply With Quote
Old Dec 30, 2012, 03:53 PM
less is more
Knoll53's Avatar
United States, CA, Marina
Joined Sep 2006
2,815 Posts
This is a Sketch Up animation

Plank DS Landing (0 min 0 sec)
Knoll53 is offline Find More Posts by Knoll53
RCG Plus Member
Latest blog entry: Air Plank and the Hawk
Reply With Quote
Old Dec 31, 2012, 03:13 AM
I don't like your altitude
Stupot46's Avatar
Joined Sep 2011
3,251 Posts
Neat.
Stupot46 is offline Find More Posts by Stupot46
Reply With Quote
Old Jan 04, 2013, 11:24 AM
Registered User
RyanNX211's Avatar
Upper Arlington, Ohio
Joined Dec 2007
1,441 Posts
why such a long aerial ?
RyanNX211 is online now Find More Posts by RyanNX211
Reply With Quote
Old Jan 04, 2013, 01:09 PM
Registered User
Joined Mar 2008
627 Posts
Quote:
Originally Posted by Knoll53 View Post
Especially for a little wing like this, a quick, simple and inexpensive building method is part of the attraction. Sig Rhino Hide looks like it might fill the bill for a wing covering and structure. It is a wood product and when bonded to the foam with PU glue, it creates a stressed skin panel that is stiff and strong. From a structural point of view, the Rhino Hide might be the perfect companion to the foam. Would this wing be ready for a 200 mph DS loop? Probably not, but any frontside flying should be good.

This mock up had the skins vacuum bagged on to the foam with PU glue, then a balsa LE added with PU glue.

Kent
How thick is the "Rhino Hide?"

Also, does it seem like wood veneer?
Cap_n_Dave is offline Find More Posts by Cap_n_Dave
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question Foil for 60" DS plank wooden wonder taurineman Dynamic Soaring 14 Oct 18, 2012 04:06 AM
Cool The Splinter DS - Brit Assult on the Plank DS Record Geo420 Dynamic Soaring 104 Nov 20, 2009 02:37 AM
Design ideas for an EPP Slope and DS Plank ifrichard Slope 7 Oct 27, 2003 08:46 AM
Help choosing Airfoil for 60" DS Plank occy Dynamic Soaring 5 Oct 20, 2003 02:02 AM