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Old Jan 16, 2012, 12:24 AM
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Knoll53's Avatar
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Operable Main Skid

The main skid is all plywood and CF.
It's latch is tied to the spoiler servo.
It's operation will be similar to this.

Kent
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Old Jan 16, 2012, 11:53 AM
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Kent,

that looks already very nice! Just curious, how large is the center section? Is it like 1/3 of the span?

Lothar spoke some days ago of separating the wing directly at the center. In such a way that, it would be easy to use the wing as a pure glider or as a motorized Horten - by inserting a small inlet between the wings. Of course, the bending moment is large, but the shearing force is small. I like your solution too! Do you make the joiners yourself? The landing skid is a nice gimick Are you planning to have also some type of spoiler for landing?

Regards,

Andrés
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Old Jan 16, 2012, 01:02 PM
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Knoll53's Avatar
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Andrés: Thanks. The center section is 1040mm span. It has spoilers and a main skid controlled by one servo. The spoilers have not been modeled yet. See drawing. My guess is that spoilers will cause a definite nose down attitude. If so, I'll mix in some up elevon for hopefully a very draggy plane. I have small landing zones in Big Sur. So when are you and Lothar coming out for some alpine soaring in Big Sur???

I'm not sure exactly what configuration you are suggesting, but alternate center sections could be done. A very small center section could be powered for a more compact plane.

The joiner is built from a plywood box that has a final shape of 3/8" x 1" deep. That plywood box provides form work for 1/4" x 1/4" CF tow spar caps. It has a solid vertical grain balsa shear web. This type of joiner is cheap to laser cut and the CF tow at 50K is still inexpensive. This reduces the number of expensive parts to buy (carbon rods and pipes) to complete the build. I may be able to laser cut 100% of the parts. The main spar caps are CF tow. The LE will be plywood over balsa backing. I've got no sticks of wood in this plane.

In the wing, the joiner sleeves will be plywood boxes inside of the main spar and will be fully wrapped with Kevlar.

Regards,
Kent
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Old Jan 17, 2012, 11:46 PM
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Main Skid Linkage

The spoiler servo also drives the latch for the main skid. The skid has a spring pulling it open, so it may be deployed once per flight.

Kent
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Old Jan 20, 2012, 09:49 PM
TjW
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Quote:
Originally Posted by nmasters View Post
It looked familiar to me. It's a very early Mitchell wing. Designed back in the '40s. You can see it or a later plane built from the same plans at 5:36 in this video. You might also recognize some names. I didn't realize until I saw this that Steven Morris is Australian.
http://www.youtube.com/watch?v=BRnMedC1tXo&lr=1
He could be, but I think they were talking about Steve Moyes, Bill Moyes' son.
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Old Jan 20, 2012, 11:23 PM
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Originally Posted by TjW View Post
He could be, but I think they were talking about Steve Moyes, Bill Moyes' son.
Yeah, now that I've listened to it with all other machines turned off and the volume really high I think I heard "Moyes". I'm nearly deaf in one ear and the very sensitive to background noise and echos. It seemed like a good guess considering that that video was posted on Youtube by Steve Morris

Norm
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Old Jan 23, 2012, 09:51 AM
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Got a little done this weekend. Spoilers and jigging strips.

Kent
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Old Jan 23, 2012, 11:06 AM
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Heidelberg
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Kent,

that looks great! You are using one servo for both spoilers and landing skid? I like direct links, but this solution is of course a lot lighter and cheaper. I have been playing with the idea of using spoilers to create at least a sort of weak ruder. In my current project "Tümmler" (porpoise), I did the spoiler control as shown in the photos. I'm still not done and wating eagerly for the maiden

Regard,

Andrés
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Old Jan 23, 2012, 12:00 PM
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Originally Posted by andrecillo76 View Post
You are using one servo for both spoilers and landing skid? I have been playing with the idea of using spoilers to create at least a sort of weak ruder.
Yes, one big standard servo for all three. I consider spoiler and landing skid as non-essential functions, so I group them. If the spoilers close flush, I'm happy. Adjustments done mechanically at the servo.

Spoilers as rudders! Very tricky. There is not much moment arm on that rudder but it will certainly work. I could retrofit your system later. It would be interesting to see if you could fly it with just those rudders and spoilers. Set the trim for level flight and all other control input from just the spoiler/rudder combination. It's emergency training. I too am interested in your test flying. Do you have a link for this project?

In hang gliding we used to practice some emergency training such as flying without a harness and just stand on the control bar. We'd launch, fly and land this way. The idea being if the hang rope ever broke and you were left hanging from the control bar, you could do a chin up, climb up into the control bar and fly to a safe landing. This was before wide spread acceptance of parachutes.

Kent

Hang Gliding the dunes with no harness! (0 min 24 sec)

for the non-believers
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Old Jan 24, 2012, 09:40 AM
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Wow Kent,

this looks great.

By ´the way, I've made an easy design for the manatee. My Idea was to make two wings and to connect them in the center. between both wings is a "center-ribb", which includes hthe hook for the catapult and something like a "stern-skid", to make landings better. The forward connection will be made from birch plywood. In the connection box is the room for a 3s 3000mAh lipo. This battery is to be used in the sailing version as receiver battery and also good for the motorized version. I think I will fix the speed-controller in one wing and the receiver in the other one. One electric connector on the upper side of the wing will be integrated for the motor cables.

The aft connector of the wings is 8 mm CFK

I used this very easy system at my Tabu and on my minus, german prduced flying wings with winglets.

See attached file.

I think, Andrés will load the CAD-Datas up un the platform tonight.

Regards

Lothar
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Old Jan 24, 2012, 10:26 AM
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Nice Lothar. The Tabu looks like a one piece wing. That's my favorite. That plane would be fun on the slopes. Looks like I have been missing a lot by not following the German Nurflügel forums. I need to fix that.

I look forward to seeing your design for the Manatee, but from your past work and your description, I think that I understand what you are doing already. Sounds like you are using one long aft joiner that extends all the way out to the main spar. This equals maybe 1/3rd of the total span. No curved spar on this one. How am I doing so far?

It is a versatile system that allows you to easily swap out different "cabins" for power, slope or scale. The cabins are only big enough to house the various components which leaves the outer wing panels quite large. It sounds like you are placing some components IN the massive wings. Why not. There is no need for a pod to house the components with a 4"+ thick wing.

I know that your rear skid is the ideal location for the main skid. As you first touch down on a smooth surface, that skid stabilizes the final landing until you stop. I too will have 2 aft skids on either side, but my main skid is in front and will be the first to touch ground. Landings will be a "dance", I know, as the front skid touches ground because that end point of the skid is in front of the CG, but I do so for protection of the glider. My flying sites are primitive and I want to keep the wing off of the ground at all costs. Maybe I should wax and polish my skid to make it more slippery. If I had your manicured landing zones, as I've seen in your videos, I'd design the main skid differently.

Feel free to post your work here. I'm sure the guys viewing this thread would love to see your work too.

Kent
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Old Jan 24, 2012, 10:41 AM
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Heidelberg
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Quote:
Originally Posted by Lothar
I think, Andrés will load the CAD-Datas up un the platform tonight.
Yes Sir, I will I just got home from work and dinner is almost ready.


Quote:
Originally Posted by Kent
Spoilers as rudders! Very tricky.
I think for the Manatee they might be too central. The spolers are located far more outside in the Tümmler. The low directional stability of Hortens helps in the sense that a small yaw torque could be enough to yaw the wing. Maybe they manage to mimick a rudder, but their main purpose is to "spoil" The Tümmler does not need a ruder. Anyway, it might be interesting to understand the differential action of the spoilers. I do not have a link for the project at the moment; it is more or less an underground thing I've been working on. Actually those photos are the first ones I publish. Maybe some day I'll start here a thread...

Regards,

Andrés
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Old Jan 24, 2012, 11:09 AM
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Language Translation... always interesting

Andrés: I had to laugh when I first read the name of your project the "Tümmler" (porpoise). I get it, of course, you have a biological oceanic theme with your project names. Manatee and porpoise. But "Tümmler" as read in English rhymes with "Tumbler", which is a topic that I have personal experience with.

Back in the 1970's I worked for a Swiss engineering firm VSL. They made steel cable systems, including ski lifts and gondolas. At one point they had a new high wire gondola product that was intended to give "fun" rides to the public. So they named it "Fun-I-Rail", which sounds like "Funeral" here in the States. It took some doing, but we finally convinces them to re-think the project name.

I hope you find this amusing.

Kent
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Old Jan 24, 2012, 11:16 AM
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Germany
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Well Kent,

for me it looks a bit like You try to make a prototype plane for Your Horten Xc. My Idea is to restart my flying wing builts with something very easy. I want to have this plane as my "allround toy". I think it's small enaugh to have it always in my car as I had my Tabu and the Minus for years.

For the Tabu and the Minus have a look at smg-gerten.de. I think Walter Gerten produces very good planes from Obeche and Styropor. The Minus is rocket at the slope.

Great to make complete different planes with one design

Regards

Lothar
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Old Jan 24, 2012, 11:34 AM
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Lothar: I am hoping to thermal fly my Alpine Sled (Manatee). For me, it's massive outline in the sky will be welcomed because I cannot see the little wings when they get sucked up into cloud base. It is more of a comment about my eye sight rather than the altitude.

The Tabu is a nice ship. Maybe the perfect flying wing. The highly tapered wing that terminates at a modest winglet just looks right. Looks like I've got another wing to add to my "to build" list. The Tabu at 3m would be fun for me.

Thanks,
Kent
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