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Pirschjaeger
01-14-2007, 01:13 AM
Hi TT,

if I remember correctly, you are an a/c mechanic.

I can't seem to find any info on the leading slats of the 109. I'm curious as to how they worked mechanically. Were they held with "springloaded" pistons and depressed by air resistence?<div class="ev_tpc_signature">

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Hanglands
01-14-2007, 05:21 AM
Hi,

OK Im not TT, but I found this in Crecys Pilot Notes for the Bf 109:

"Slots

The slots occupy 46.2% of the span and extend well inboard of the ailerons. The slat is articulated to two transmission rods which run straight out of the wing and are luinked together by a robust system of rigid rods and bell-crank levers. The slots open and close very freely and when closed fit very well between the wing and the slat. <span class="ev_code_YELLOW">There is no damping device in the mechanism.</span>"

Thats all it says. I dont know if we're to take that 'damping mechanism' to mean a springloaded set up as you describe.

Would be interested to know too....<div class="ev_tpc_signature">

http://i105.photobucket.com/albums/m203/ChickenHawk_2006/logoHH.jpg (http://www.geocities.com/hanglands/)

slipBall
01-14-2007, 05:26 AM
While you are waiting for TT....you can read some info here
http://www.virtualpilots.fi/feature/articles/109myths/<div class="ev_tpc_signature">

http://i51.photobucket.com/albums/f394/SlipBall/orders.jpg

Tully__
01-14-2007, 05:41 AM
Originally posted by Pirschjaeger:
Hi TT,

if I remember correctly, you are an a/c mechanic.

I can't seem to find any info on the leading slats of the 109. I'm curious as to how they worked mechanically. Were they held with "springloaded" pistons and depressed by air resistence?
Yes. As Angle of Attack increases the high pressure area on the front of the wing moves down and below the leading edge. As the pressure on the upper leading edge drops, the slats pop out.

The post that refers to a lack of damping means that they don't ease out. As the pressure moves below the pressure required to keep the slats in, they pop fully out in one go.

In a turn, the location an intensity of the leading edge pressure area differs from one wing to the other. This means that the slats will pop out one side before the other in a turn which will surprise a pilot not experienced on the type but not experienced pilots.<div class="ev_tpc_signature">

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Taylortony
01-14-2007, 11:08 AM
Yes, BTW Im an Engineer actually http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Ok they are as said above totally automatic and they come out with the drop in air pressure literally sucking them out.......

And speaking from experience they are as said noisy from in the aircraft, they bang out and in, indeed when you are on the edge of them operating one way or another they can be seen to be literally "floating" with a sort of juddering sensation as they decide what they are going to do.............. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif
Now you may ask........
Hmmm how has he got first hand experience of these?, well the PZL Koliber which is a Polish built Robin has the exact same system fitted on their wings and it is in use today....

Was glad to see it go, It had all sorts of brake problems I struggled with to fix after the pilot doing a practice force landing managed to tear the port leg off and drag its sorry *** off the side of the runway on a wing.
I will give it one thing, it was strong, because even though the lower part of the leg was torn clear, the spars were fine and some juditious whacks with a big hammer so was the wing tip and ailerons...

The brake problem was after bleeding it. it had air in the system 2 or 3 days later and no brakes, must of bled it about 40 times ( No Kidding) and at that point I pulled the NEW factory brake unit off, immersed it in brake fluid and was amazed to see the metal was actually gassing with being in contact with the fluid..... go figure, a new new caliper assy cured it http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

http://www.pprune.org/forums/archive/index.php/t-82065.html

http://www.aviline.com/rallye/slats1.jpg

Pirschjaeger
01-14-2007, 12:10 PM
Hey thanks all http://forums.ubi.com/images/smilies/25.gif

TT, as I was reading the last post from the thread you linked it finally hit me as to how they worked if not spring loaded. I kinda overlooked the fact that the top of the slat extends further back than the lower part. The explanation in that thread reminded me of what the most important part of the design was. http://forums.ubi.com/images/smilies/35.gif

I'm sure they would have been dampened. If not, the least little bit of crud on the sliding ram would have meant frequent jamming.

For stability I would imagine the cylinders would have extended almost half a meter into the wing. Sure would like to see some drawings if you have any.

Thanks again TT. http://forums.ubi.com/images/smilies/25.gif<div class="ev_tpc_signature">

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Vike
01-14-2007, 06:06 PM
Originally posted by Pirschjaeger:
Hi TT,

if I remember correctly, you are an a/c mechanic.

I can't seem to find any info on the leading slats of the 109. I'm curious as to how they worked mechanically. Were they held with "springloaded" pistons and depressed by air resistence?

All the truth is here mate!

>> 109Lair/Slats << (http://109lair.hobbyvista.com/techref/systems/control/slats/slats.htm)

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Pirschjaeger
01-15-2007, 12:04 AM
Thanks Vike,

that one covers everything. I was especially surprised at the mechanics but they are more logical in design than what I had imagined. I was curious about the weight of the mechanism and the insurance both mounted areas would extend evenly.

The reason I was so curious about this is that for years I've been dreaming of building a large scale(2-3m wingspan) 109 for many years.

My goals are to figure out the best and cheapest possible construction, lightest materials, and keep it very accurate in detail, including working slats.

Living in China means the availability of materials, such as balsa wood, is not very good. Very few Chinese have hobbies. I don't speak the language either, making it even more difficult to find stuff. So I'm forced to come up with new and unorthodox ideas.

Recently I'm interested in using paper. Sounds crazy but with a little patience, the right folds, and a good lightweight glue, paper can become a relatively strong frame while remaining very light. A mostly paper frame covered with thin balsa sheets could make the model strong enough.

If I were building a WW1 plane it would be much easier, but not as challenging. http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif<div class="ev_tpc_signature">

http://i11.photobucket.com/albums/a198/FritzFranzen/Sig11.jpg

Valhalla Kittens (http://www.dennyweb.com/viking_kittens.htm)

"I furiously yelled an ancient Anglo-Saxon single syllable word referring to the act procreation about a dozen times." Blakduk as he was looking for Ctrl + E in his Ford Falcon XT