ASK13 1/3 Scale**

[patte de loup]

Herewith some pics of the ASK 13 which is located in Strasbourg ( East of France )
BTW , Thanks Cliff for your support
Pat'

[patte de loup]

And the 2 last
Pat'

[Peter Balcombe]

Many thanks for the pictures Pat.
They will be a great help in the cockpit area detailing.
Peter

[Peter Balcombe]

This build is based on a full size which has both nose wheel and tail wheel, so having built the forward fuselage using the required parts for the nose wheel option, it is time to turn my attention to modifying the rear end to take a tailwheel.

During my research for this (with many thanks to GeeWee & Lez Saker) I have discovered that the bottom of the finpost on the full size doesn’t taper as much as on the plan, where Jilles has simplified matters a little to provide a 12mm wide solid skid built into the rear keel - tapering the bottom of the finpost to suit.
However, if you wish to modify for a sprung skid or tailwheel, then the following might be of interest.

The base of the finpost on the full size is more like 85mm, so just under 29mm @ 1/3 scale.
The full size tubular framework at the keel is a single tube moving towards the rear from the mainwheel area until below the forward part of the fin, where it then splits into 2 tubes, each going back to opposite sides of the finpost base.
On gliders fitted with sprung skids, the skid is then attached to the bottom of the fuselage framework.
On gliders fitted with a wheel, the 2 tubes are replaced by a “tuning fork” type arrangement, with the tailwheel axle attached to the bottom of the “prongs” of the fork.
One image below shows a glider on tow, with the lower rear fabric “bulge” around the wheel aperture. Another shows the exposed tubular framework on a damaged glider - showing the “tuning fork” framework around the wheel.

I’ve currently cut out the rearmost keel section on my build & added a couple of “cheeks” to the bottom section of the finpost to reduce the taper to give 30mm width at the base. The intention is to insert a replacement ply keel assembly whose shape simulates the “tuning fork arrangement” onto which the wheel axle can be attached.

[Peter Balcombe]

A new lower rear fuselage section has been fitted which transititions from the 4mm ply keel member to the widened (30mm) finpost base as shown below - trying to emulate the ‘tuning fork’ like shape of the framework on the full size a/c.
This plate is made from 3 layers of 1/8” ply & the centre of the wheel aperture is braced back to the upper fuselage longeron using 1/8” ply. The aperture is sized fora 70x23mm wheel which is virtually spot on 1/3 scale for the full size 210x65mm.
The edges of the plate have been faced with balsa & profiled to give a better gluing area for the skin panel to be fixed once the wheel fit has been checked & the axle plates fitted.

The wheel will be mounted on brass 2 axle plates yet to be made, slightly recessed & bonded to the sides of the ply plate, so that the plate replicates the full size external appearance as much as possible.
The wheel attachment appears to be a large bolt on the full size - at least from the pic below, although I’m sure there will be a locking device.

This lower section of the fuselage is fabric covered on the a/c in the picture, but I will probably skin the model with 0.4mm ply rather than 0.6mm to deal with the complex curvature at the forward end whilst still giving a smooth surface.

[Peter Balcombe]

Thanks to input from GeeWee & Lez Saker at the Mendip Giding club, I’ve managed to find the attached info about the rear skid installation.
The skid is a simple length of approx. 20mm steel angle/sq. tube, bolted via flexible mount to the lower fuselage at the front & via a rubber shock mount, bolted to the lower fuselage at the back. A replaceable wear shoe is welded to the rear end. The rear shock out may be about 50mm wide & 100mm or so diameter (but see pics below).
The overall skid assembly is often covered in (to keep out field muck) using a vinyl type material, maybe secured to the skid by bindings through small holes in the skid.

The photos below show a couple views of a skid & rubber mount when removed from the a/c, plus a sketch showing some dimensions of the full size arrangements: wheel version at top & skid version beneath.
Note that sizes on the sketch are a 1:1 scale.

I hope this is useful to anyone looking to make either revision to the standard plan design.
Peter

[Jilles]

well this is one option, probably a local retrofit/invention like front and tail wheels
The original skids on the K4 up to K13 Schleicher models were a spoon type structure from spring steel, bolted straight to the fuse, the spoon under the rudder no rubber in sight

[Jilles]

hard to find pictures of skids on the internet but attached should give some idea what I meant in previous post

[Cliff Evans]

3d print of tailskid rubber. Printed using ninjaflex which is a flexable rubber type filament. You can print so that it is really squishy or make it as hard as neccesary to emulate the real thing. Thus has been printed so that it emulates the real thing.

[catwok]

Nice bit of detailing Cliff... Are they available to buy and do you make them in all sizes?