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        Discussion Micro gliders...

#1 Yellow Baron Oct 28, 2010 01:30 PM

Micro gliders...
 
I've been experimenting with gliders under 24" lately, and have had some decent results, but I "over-tested" both of my airframes (Yeah, crashed them both beyond repair). I'm just wondering if anyone else has any input or is actively working on such a project.

Other links that may be of interest:
My Zogling
Indoor towing from Finland
Alien Tech's Blanik kit
Derk's micro slope soarer
Ralph B's Amphitheater Slope Soarer
RetoS.'s 14.8g motor glider with folding motor and pylon
Micro gliders in the HLG style
Derk's micro glider build

#2 Yellow Baron Oct 28, 2010 01:34 PM

Redundant....

#3 PeteSchug Oct 28, 2010 02:51 PM

I'm sure you've seen this, but here is the link anyway.

http://www.rcgroups.com/forums/showthread.php?t=1328733

It's the Finnish guys who do indoor towing of very small and light gliders. Their release is as simple as it gets. There is no release! It's just a piece of rod, CF probably, set 90 to the fuse sideways and they hold a little rudder to keep it on, then turn the other way to release.

Their gliders are very light and run about one meter span. My Vampyr is planned for about half of that. They stick to 1/15th scale, my Vampyr is 1/20th.

I don't even know what the scale of the Zoegling is, but it's really small.

Still haven't glued two sticks together even though I've got a lot of cut parts.

Got to get my Dremel driven bass wood stripper working.

Pete

#4 derk Oct 28, 2010 04:03 PM

here are a few older threads about micro gliders:
http://www.rcgroups.com/forums/showt...t=slope+glider
http://www.rcgroups.com/forums/showt...t=slope+glider

#5 chispas2 Oct 28, 2010 05:59 PM

Hi.

I have build two motorgliders, a Grob/Valencia, at 27,5" and 0.75oz, and a SG-38 with and without motor. The one with motor, at 18" and 0.56oz, and the other at 17" and 0.4oz:
http://c10.quickcachr.fotos.sapo.pt/...411_gstG5.jpeg
http://c9.quickcachr.fotos.sapo.pt/i...609_V7Glz.jpeg
http://c8.quickcachr.fotos.sapo.pt/i...175_G9pNy.jpeg
Videos at http://www.youtube.com/user/PChispas

I prefer to work around 1/24th scale and on the fase of deciding the next one, will be a vintage but maybe go with a profile one first.

Have good flights.
Chispas

#6 Mike Tully Oct 29, 2010 11:05 AM

1 Attachment(s)
I'm working on an Earl Stahl Schweitzer TG-2 using a PZ brick. Intended for scale aerotow with a HZ Champ as tug. The video from the Finnish guys was encouraging.

#7 PeteSchug Oct 29, 2010 11:34 AM

Quote:

Originally Posted by Mike Tully (Post 16414099)
I'm working on an Earl Stahl Schweitzer TG-2 using a PZ brick. Intended for scale aerotow with a HZ Champ as tug. The video from the Finnish guys was encouraging.

I've got those plans on this computer. They are available on this site, along with a lot of really nice Earl Stahl plans:

http://www.theplanpage.com/esp.htm

A while back I was working on a design for a Schweizer 1-26 with wings that unfold a la the Jim Walker Interceptor. I gave up when I decided that the Vapor brick was just a bit too big for the size model that I was working on. The plans were not spectacularly good or I'd post them even though I never built the glider.

I mention the above because I still think the idea is very good even if the Vapor brick would have been a little big and the battery only made matters worse.

I'd post my Vampyr plans but they are basically just three views with nothing much shown in the way of structure. In fact, I built two unsuccessful fuses figuring out how things have to be done. A third is in progress but buried under paperwork and mail relating to my recent retirement, which has turned into a paperwork nightmare. I've also been thinking of enlarging it from 1/20 scale to 1/15 to allow a little more breathing room for the gear.

Pete

#8 Yellow Baron Oct 29, 2010 12:34 PM

Nice gliders everyone!

Pete, do you happen to have plans for the Vampyr or are you just winging it? (pardon the pun)

#9 PeteSchug Oct 29, 2010 01:29 PM

Quote:

Originally Posted by Yellow Baron (Post 16414700)
Nice gliders everyone!

Pete, do you happen to have plans for the Vampyr or are you just winging it? (pardon the pun)

I have scale drawings that I made using three views from Bob Banka. I also have the drawings in Martin Simons' books. There are discrepancies between the Banka drawings and the Simons' ones and neither of them quite matches the photos.

The drawings from Banka show a scalloped trailing edge but Simons and the photos show a straight TE. The fuse tapers from right behind the bulkhead that is the back of the pilot's seat, but both Banka's drawings and Simons' show the taper starting from the TE of the wing.

The wings were made in three parts, and the outer sections are flat with the top of the wing (no dihedral) but taper up from the bottom. I do not plan to do that. The swept outer panels had a sort of wing warping aileron and I am planning to have hinged ailerons. The wings were probably tapered to get the thin section for the flexing ailerons. No thanks, WAY too much work.

I will probably make the tail surfaces out of 1/32nd sheet but in photos you can see that the light passes through the wing, tail and rear parts of the fuse!

That would look really great but not very practical for something this small.

The airfoil I have in mind is flat bottomed, with sliced ribs

Some of my planning is hand drawn on my plans, and not convenient to stick into my scanner, especially since my building space is buried under retirement correspondence.

So that's it for now on the Vampyr plans. Basically I'm working over some inaccurate three views, but with photos that enable me to figure out what's wrong with the drawings and I am also modifying anything that is very difficult to duplicate.

A final thought. The year after the hour and two hour flights they added a bigger rudder. I think that indicates that strong coupled aileron and rudder is probably required. I was thinking of a gyro, but aside from modifying an mSR brick I can't think of a reasonable way to stick a gyro in.

Pete

#10 Alien_Tech Oct 30, 2010 09:57 PM

3 Attachment(s)
I stumbled across this thread last night and nearly fell out of my chair. I knew immediately I had to build one, especially after seeing the indoor video! :D

I browsed the Scale Soaring UK site and found the Blanik L13 3-views. I have always liked this plane since I was a kid, and even so more recently in the wild Red Bull acro video. (Here it is in case you haven't see it
Skydiver moves between gliders in mid-air! Red Bull Akte Blanix 2 (2 min 49 sec)
) Anyway, a few hours this morning and I had it designed in CAD for ParkZone gear. It ended up with 38" span. I cut it out of 3mm Depron to see how everything fit and to check size. I usually don't have a good feeling for how a plane looks on the screen, so it's a bit of a crap shoot until it's cut and I can see it with my own eyes. Well the size and porportions looked ok, so I built it up as a "chuck glider" to check gear fit and C.G. I tossed it in the front yard and the glide is long and flat. The wings have a bit of flex, so I'm either going to add some carbon or a second layer of 3mm Depron and make it a KF style wing. I still need to figure out how to do the linkage for the dihedral tail. I may just leave it, but it would really look good with it!

Once I figure out the wing fix, I'll cut another tonight and hopefully fly it for real tomorrow. I have no idea what it weighs. I hope my Champ or T-28 will pull it!

C-ya

BTW.....I have a Reiher V2 ready to cut too :cool:

#11 Alien_Tech Oct 30, 2010 10:01 PM

1 Attachment(s)
Here is the Reiher V2. I'll need to reinforce the wing on this too before I cut it.

Cheers

#12 3D Devil Oct 31, 2010 04:14 AM

Hello guys,

Glad to see, you have started your glider projects.

Alien-Tech, We didn't test flat airfoil on our gliders. Please, let us know how it works when you have results.
We curved a bit of our airfoil which give also some stiffness for the wings.

Nice work!

BR,
Kimmo

#13 Alien_Tech Oct 31, 2010 04:48 PM

2 Attachment(s)
Kimmo,

I thought about a curved airfoil, bit I wondered if the Re numbers that these fly at it might create more drag than lift? Anyway, I went with a KF type that seems to make it stiff enough.

This what I have so far today, I have go carve pumpkins :D It weighs 31gm. without pushrods, hope it's not too heavy, I don't recall what the others came it at. After a little bit of Sharpie art, it certainly won't win any scale contests, but I think it at least captures the spirit of a Blanik.

Hopefully it will fly tomorrow.

#14 3D Devil Oct 31, 2010 05:27 PM

Nice job!

Good luck for maiden!

BR,
Kimmo

#15 ShawnM4kq Nov 01, 2010 02:21 PM

how'd it go?


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