HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Feb 07, 2011, 02:58 PM
TheyreComingToTakeMeAway!
derk's Avatar
USA, ID, Coeur D'Alene
Joined Dec 2003
5,406 Posts
Build Log
Micro Glider Build

well, glider season will be starting soon and the slopes will begin ripping so i thought i would start on a micro glider to play with. i have long loved the lines of the european performance flying wings so i am modeling this one after them. i am not sure why more people in the states do not build gliders like these as they seem to perform very well...

anyways, its basic all balsa and ply construction. so far i have a small scale freeflight built and the actual model's wings carved out. carving wings from sheet wood is actually quite easy and quick. i think it only took about 30-45 minutes total to get them to this point.
of coarse having the proper tools REALLY helps this along, the main ones being a planer and sanding block. i start by drawing a line down the wing of the area to be removed and then start planing it away until i just reach the line. for a flying wing like this its a little more complex needing some built in twist and different airfoil at the tips than the root. so because of this, i made the line tapered (wider at the root and narrower at the tip) and when planing, i make the inner 50% have a normal taper to the trailing edge. the outer 50% gets planed until the tip trailing edge is about half the thickness of the original sheet wood. flip it over and carve away until the trailing edge is a uniform thickness.

then you can carve the leading edge, about 30% of total chord works for me, start with a large shallow cut and go deeper and narrower until the front is nice and sweeping. once all that is cut to a general airfoil shape, i start sanding it with 180 grit paper and then again with 320 grit. you could go further and sand with even finer paper but i just use what i have on hand

i am planning on starting the pod later today, but haven't decided on gear arrangement yet.

the span on this one is 24" and has about a 25 degree sweep. chord width along the swept angle is 1.5"

i plan on using al. tubes and steel torque rods for the elevons for a clean setup.
also i have been wondering what to finish the wood with? should i go and do layers of paint and primer, or just clear coat and sharpie coloring?
derk is offline Find More Posts by derk
Reply With Quote
Sign up now
to remove ads between posts
Old Feb 07, 2011, 04:53 PM
Registered User
chispas2's Avatar
Mem Martins, PORTUGAL
Joined Jan 2002
231 Posts
Hi, Derk.

Nice wing. Why not go the paper/tissue covering with dope route? It will get light and very smooth finish.

Have good flights,
Chispas
chispas2 is offline Find More Posts by chispas2
Reply With Quote
Old Feb 07, 2011, 05:14 PM
TheyreComingToTakeMeAway!
derk's Avatar
USA, ID, Coeur D'Alene
Joined Dec 2003
5,406 Posts
Well I figure solid balsa is more slope compatible
The abuse that slope planes need to take is pretty rough even if you try to baby them.
derk is offline Find More Posts by derk
Last edited by derk; Mar 01, 2012 at 02:31 AM.
Reply With Quote
Old Feb 08, 2011, 11:18 PM
TheyreComingToTakeMeAway!
derk's Avatar
USA, ID, Coeur D'Alene
Joined Dec 2003
5,406 Posts
Well, yesterday I had a little oops in judgement. I used a heavy laminate film on the wings I built and am not happy with the outcome
Soooo, I started something different but along similar lines. A more straight wing to get the stiffness I wanted on the other one. This one I also added a hardwood leading edge which will really make it durable. I tried it out as just a plank with a tiny pod and fin but I think it may end up as a standard wing and tail.
Still debating finishing techniques, thinking tissue and wbpu may be what it ends up with.
derk is offline Find More Posts by derk
Reply With Quote
Old Feb 09, 2011, 03:00 AM
Registered User
PeteSchug's Avatar
Elmhurst, NY (Queens in NYC)
Joined Apr 2004
6,973 Posts
Looks good. I'd worry about warping the TE using a water based finish, but I guess you probably have more experience in that area than I do.

Pete
PeteSchug is offline Find More Posts by PeteSchug
RCG Plus Member
Latest blog entry: Some Books About Flying
Reply With Quote
Old Feb 09, 2011, 03:27 AM
Registered User
AleG's Avatar
Bangkok
Joined Oct 2007
1,587 Posts
Japanese tissue and dope work great for covering balsa wings. I've done many Free Flight hand launch gliders that way and you can get a super smooth and relatively tough skin. Also if it's well doped it will protect the wing from warping from changes in humidity (up to a certain degree at least).
AleG is offline Find More Posts by AleG
Reply With Quote
Old Feb 09, 2011, 08:08 AM
0.9g retracts
Yellow Baron's Avatar
3" from insanity, 2' from the computer ,Richford, Tioga county, Southern Tier, New York, U.S., North American Continent, Northern hemisphere, Earth, The Sol System, Milkyway Galaxy, The Universe, The Current Dimension, Your Selected Realm of Reality.
Joined Dec 2006
1,945 Posts
Really cool glider Derk, make sure you post a finished product in the Micro Glider thread!
Yellow Baron is offline Find More Posts by Yellow Baron
Reply With Quote
Old Feb 09, 2011, 08:19 AM
Airplane Killer
SumthinsFishy's Avatar
Orange County, CA
Joined Oct 2009
1,703 Posts
Quote:
Originally Posted by Yellow Baron View Post
Really cool glider Derk, make sure you post a finished product in the Micro Glider thread!
Micro Glider thread???
Dave
SumthinsFishy is offline Find More Posts by SumthinsFishy
Reply With Quote
Old Feb 09, 2011, 08:22 AM
0.9g retracts
Yellow Baron's Avatar
3" from insanity, 2' from the computer ,Richford, Tioga county, Southern Tier, New York, U.S., North American Continent, Northern hemisphere, Earth, The Sol System, Milkyway Galaxy, The Universe, The Current Dimension, Your Selected Realm of Reality.
Joined Dec 2006
1,945 Posts
Right here: http://www.rcgroups.com/forums/showthread.php?t=1329802
Yellow Baron is offline Find More Posts by Yellow Baron
Reply With Quote
Old Feb 09, 2011, 06:11 PM
TheyreComingToTakeMeAway!
derk's Avatar
USA, ID, Coeur D'Alene
Joined Dec 2003
5,406 Posts
chasing a perfect flight

well, i took out the little V wing to the park ad really ringed it out.
i managed to get it flying nearly perfect to what i would want a larger one to fly. with just the right mix of wing twist, reflex and camber, i could throw it as hard as i can, it would climb at a straight 15-20 degrees and then transition to a slow glide.

heres how its all working:
wing twist; on most flying wings there is a certain amount of wing twist frm root to tip that gives it the right amount of stability a tail would normally provide. for mine i removed nearly all twist but maybe 1-2 degrees, instead i added a tiny bit of reflex but only at the very outer part.

camber; this is something thats not as common to flying wings as not all can HAVE it. for my wing it has camber ONLY ahead of the CG so it will not cause any dive tendency.

heres how these 2 things interact, the low wing twist means at high speed the plane doesnt want to pitch up. at the same time, the high speed causes the air to detach from the cambered section also not causing the nose to pitch up. when the plane bleeds off enough speed, the camber starts lifting slowing the plane and settling into a low speed glide. this is all due to a change in the center of pressure from high speed to low.

its my belief that this would make for an EXCELLENT catapult or bungee launch glider.

has anyone else played with a setup like this?
derk is offline Find More Posts by derk
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Steelhead FRY Micro SAL glider build eerrp Hand Launch 39 Feb 03, 2006 06:22 PM
Micro glider build-off!! 2 day!! watersharer Scratchbuilt Indoor and Micro Models 31 Apr 03, 2005 09:56 PM
Want to build micro ep glider growermn Scratchbuilt Indoor and Micro Models 3 Oct 21, 2004 09:04 AM