Just putting the Storch in the right bit of the site..  Quick reminder - Storch required to tow up Olympic event gliders for commemorative events in 2012..   1/4 scale gives a span of 3.56m, 2.475m length.  AUW under 20kg target, and sufficient power to pull up at least 1/3 scale woodies.  Bigger won't fit in my car, 1/4 is a challenge for transport and storage.  The tail feathers will have to be made removable for this reason.

Two plans currently under consideration, von Kriz and Ed Newman. 
First uses foam board, PCV tube and 5mm spars! and a 50cc motor on the plan.  But it's 15kg..   
Second is more scale, steel tubing centre section in the fuselage, and the original used a Laser 320, and reported as underpowered, and weighs 23kg.  Significant issues with keeping the tail weight down to avoid nose ballast.

The Kriz plan clearly needs some mods to cope with the stresses of tug work, so out with 25mm PVC and in with 35mm carbon tube in the wings...  Swap foamboard for ply or balsa... 

The Newman plan whilst better scale detail is certain to be over 20kg, and is also not the cheapest solution.  I would have to buy lazer parts from the USA as he won't release CAD data to Belair.

For power to be ample I am thinking DA85. (8.5 hp)   I suspect the Storch will have drag by the bucket load, and need the power to fly fast enough for a safe tow.  But, and it's a significant concern to me, the engine will not fit in a 1/4 scale cowl.  About 25mm would stick out of the bottom, and the exhaust is going to use much of the front fuselage.   The DA50 (5 hp) is almost small enough to hide in the cowl fully.  For the later a slightly oversize cowl would hide it.

Thanks to everybody who has already commented on the other thread http://scalesoaring.co.uk/yabb/yabb2/YaBB.pl?num=1249634665/43#43 or the LMA forum on this.  Any advice and comments will be very welcome.    Eventualy hope this becomes a build thread!

Graham

more

and more
old and new ones

to transport the wings....and never put the box in the grass were ants are 

Noël - many thanks for the pictures.  They are very interesting.  I will be at Middle Wallop on Saturday morning only.   I would appreciate the chance to copy the CD onto my laptop if that is possible on Saturday.  Was this one 1/4 scale too?

Does it fly with enough authority to be a tug?  I really hope to have the legendary Storch low speed ability but also fly fast enough to keep gliders away from the stall on tow.  The choice of engine size is of great interest.

Graham

Hi John and Graham,
This was the one. I will bring the CD and hoop to get there before 10 am.
Noël

Thanks to Noël as well.

Now armed with all this information I am running out of excuses to make progress. 

Graham