Twin Astir Retractable gear door mechanism pictures

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Anyone out there got any pictures, diagrams or a good description of the linkage that closes and opens the gear doors and its attachment points on the doors and main wheel strut? The doors on the one in my club were broken long ago (we are on a fairly rough grass field) and never refitted. I'm now trying to figure out how replacement units would would attach and be connected.

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Here (http://www.fsv2000.at/newssystem/frameNews.php?id=1509) are some pictures of the parts with some details visible:

http://www.fsv2000.at/newssystem/imagesNews/2011_09/images/TwinFW_7.jpg
http://www.fsv2000.at/newssystem/imagesNews/2011_09/images/TwinFW_3.jpg

If I remember correctly (my club used to own one, and the gear doors needed regular repairs), the right gear door (the small one) is kept closed by a spring and simply pushed open when the asymmetric gear system swings to the right to put the gear down.

The left gear door (the large one) is actuated by a long (more or less 5-6 inches) push-rod bolted to a metal tongue welded on the rear side of the steel tube rectangular structure that surrounds the wheel.

Be aware that there are at least two variants of the retracting system...

[GM]

On Saturday, September 20, 2014 11:41:57 AM UTC-4, wrote:
> Here (http://www.fsv2000.at/newssystem/frameNews.php?id=1509) are some pictures of the parts with some details visible:
>
>
>
> http://www.fsv2000.at/newssystem/imagesNews/2011_09/images/TwinFW_7.jpg
>
> http://www.fsv2000.at/newssystem/imagesNews/2011_09/images/TwinFW_3.jpg
>
>
>
> If I remember correctly (my club used to own one, and the gear doors needed regular repairs), the right gear door (the small one) is kept closed by a spring and simply pushed open when the asymmetric gear system swings to the right to put the gear down.
>
>
>
> The left gear door (the large one) is actuated by a long (more or less 5-6 inches) push-rod bolted to a metal tongue welded on the rear side of the steel tube rectangular structure that surrounds the wheel.
>
>
>
> Be aware that there are at least two variants of the retracting system...

Steph is correct. There is one version using mostly Aluminum parts, which some regard as a weak point. There is also an approved modification which opens the gear-doors and keeps them up high thus reducing the risk of breaking them in tall grass.

Uli
GM

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Thanks! That pretty much answers my question. Ours is the earlier cast aluminium main gear version. Upon inspection I noticed that the spots where the gear door links attach in the pictures has no attachment points and the area has been filed and dressed smooth. Obviously at some point they were broken and someone decided to just clean the gear leg up and leave the doors off instead of doing a full repair.

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On Friday, September 19, 2014 1:01:05 AM UTC-4, wrote:
> Anyone out there got any pictures, diagrams or a good description of the linkage that closes and opens the gear doors and its attachment points on the doors and main wheel strut? The doors on the one in my club were broken long ago (we are on a fairly rough grass field) and never refitted. I'm now trying to figure out how replacement units would would attach and be connected.

>LTB Lindner in Germany has the legal rights to Grob sailplanes including spare parts and parts manufacture. I checked on the Twin gear doors last year because one our ours (we have 3) has the early 2 piece larger gear door, and we want to replace it with the newer single panel door. The quote from Lindner was 350 Euros for a replacement gear door kit to do both doors.
Lindner has the spare parts and/or the ability to manufacture new ones if they are needed. http://www.ltb-lindner.com/g-103-ad-sb.html <

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The thing I found to be really interesting on the Grob part of the Lindner site was the service letter SL-12 from 2013 concerning the installation of control surface seals. Just bought some stuff from Streifeneder so I could install seals on our Grobs in the manner specified.