AT-AT massiv Wellpape

Disclaimer :]
als meine deutsche Gramatik extrem schlecht ist, werde ich versuchen mein Raportchen in Englisch zu verfassen. Ich will keinem, mit alle Fehlern die jeden Deutscher ins Augen stechen werden, weh tun.
Ufff....

Actually the model I built for my son for last X-mass. So the work is done. I just want to share my experiences.

Motivation. 2-3 years ago one afternoon I build from fibreboard for my son an Imperial Star Destroyer (see picture in attachment). Advantage of this construction is that it's tough. After all this time it still exist and it's still playable.
Some time later just through pure luck I found the Rabe's Millennium Falcon. It's just masterpiece. I have no Rabes patience and skills but his work made me to thing about new model.

The aim. Model should be playable again l decided to use fibreboard (Wellpappe). Size should be Lego-compatible but very important the biggest single part shouldn't be larger than ~18x18 cm^2. Why this size? Well, I just grabbed all empty Knoppers boxes from snack-bar in my work very good quality paper, fine corrugated, thickness ~1.4 mm. Another good one were PickUp's (these are a bit smaller).

Tools: Stanley knife (Teppichmesser) tough job tough tools , some set squares (Geodreiecks), compasses (Zirkel), metal rulers (Lineal), pencil, Calculator (Taschenrechner), spatulas (Spatel) and UHU Holzleim

to be continued...

After some considerations the length of bottom of the body was set on ~22 cm (a bit more than previously mentioned 18, so I made it from four layers of Star Wars Lego boxes).

The really first step in my construction were feet. The reason was quite simple from one side I wanted to have some real life part to see the size; from other these were the most AT-AT distinctive small parts, from which it could be immediately found, what model I'm working on. As model was meant to be X-mass surprise I did all planning late in the evening/night and cutting whenever. It worked perfect, but would not work for feet.

I've got from web and books some pseudo Blue Prints. Much later (actually it was too late) I found out that there were huge mistakes on them.
Still these pictures + some pictures of Master Replicas model from rebelscum and
starship modeler + SW DVDs were what I used for planning. Unfortunately the really good pictures appeared on rebelscum when I was close to finish.

Back to feet.
Bellow you can see the base of feet, than partially glued. When top was covered I measured the real height of whole part. Probably the biggest problem when working with fibreboards is imprecisions in height of finished parts. Using some maths on radii of the top and bottom and the height I calculated the circles from which the cones covering feet should be made.

Well, my maths classes were... long time ago, so it took my some time. Maybe it's trivial, but in case it could be helpful the way is bellow:

h - length of cones wall (not quite height of cone), d1 diameter of upper circle, d2 diameter of lower circle


l - perimeter of upper circle 
L - perimeter of lower (larger) circle  


We want to draw two concentric circles as on picture bellow. The shaded strip is surface of the cone.


[1]      l = Pi  d1
[2]      l = B r
[3]      L = Pi d2 
[4]      L = B R          where B is angle beta in radians


from [2] and [4]
[5]      B = l / r
[6]      B = L / R


via comparison of [5] and [6]
[7]      L / R = l / r


from picture
[8]      R = r + h


via substitution in [7] of R from [8], and l and L from [1] and [3] respectively, and cancelling out Pi:
[9]      d2 / (h + r) = d1 / r


[10]     r = (d1 h) / (d1 - d1)


The angle B can be calculated from cross-multiplication (Dreisatz) :


360°      2 Pi R 
B         Pi L  


[11]     B = 180° L / R

In my case the radii were bigger than any of my compasses so I draw them in CorelDraw and printed on 160 g/m^2 paper. The lower part of feet on the 4th picture.

to be continued...

Quote

Originally posted by Christian Lorenz
look here: http://www7a.biglobe.ne.jp/~sf…/Gallery/at-at/at-at.html

Einmal habe ich probiert, ein Papiermodel von X-wing auf Wellepape umzubauen. Das Resultat war sch...lim. Der Kleine hat mit es gern gespielt aber meine Erfahrung war besser selbst zu ueberlaegen.

Triviale Bsp: bei Papiermodel hat mat zwei Konturen von Motoren ein fuer vorn und ein fuer hinten, dazu ein Stuck Papier den man sollte entsparechend um die beide umrollen. Leider so was wurde keine 20 min in Haenden von 8 Jahrigen Burschen leben. Macht man das Gleiche in Wellpape, muss man die beide Profile deutlich kleiner machen und bis zu Helfte des Teil mit Streifen verkleben, dann drinenn ausfuellen und dann obere Teil bedecken. Als Alternative gleiche verfahren wie bei Fuessen, aber das wurde ich nur and die Stellen machen wo keine wird das Model halten versuchen. Sonst die ausere Schalle schnell zerquetscht wird. Geht man dann zu duennen Teilen da habe ich alles aus mehrfach verklebten Schichten gemacht. Es ist gut dann unterschidliche dicke Kartonen haben.

Wie gesagt das Model soll als Spielzeug dienen.

Calf
Below picture of parts needed for the calves. As the quality of picture was far from good, I've retraced some lines on the picture.
Each of calves was built out of 7 layers (see the schema in the bottom of picture). The next picture shows ready part (just without upper cover that had to be glued with half-circular joints of the feet).

Thigh
Thighs were made of 5 layers. These are cut fitting to layers in calves. The schematic picture explains how the movement in knee should be restricted i.e. the leg can be straight or slightly bent in one direction (the top upper and bottom layers are not shown in the schematic).

The left picture shows the calf with Achilles' heel (I mean the round parts ) and the upper part of the foot. The right one shows the calf mounted with the thigh. As a knee-joint I used two bolts from broken hard-drive (one from inside and one from outside). The arrow points a small bolt that later is used as restriction of movement in the hip.

Legs with all small parts and after painting with airbrush.

The bottom of the main-body was made from 4 layers (rotation of fibreboard ~45° for each next layer to make it more stable).
First I built the meddle cage, than added trapezoid walls for front part. After leaning of these trapezoids to sensible angle I measured directly on model dimension of the roof. Btw, walls and roof were 2-layerd, but on the not-closed end the inside layer was a bit shorter (to make fitting and gluing of final wall easier and a bit more precise).

In the roof of main cage I glued on each side two small magnets from broke HDs (2nd picture). As seen on 3rd picture the covers closing the "boarding hatch" have ferromagnetic screws that hold to these magnets. The floor and the roof are cut on one side. To open hatch, you need to press on this side and than the opposite side is easily accessible. I hope I don't need to explain aim of Lego plate in the floor of boarding hatch

The triangles fitting slits between middle and outer cages were also dimensioned directly on the model.

If anybody would like to use this technique I made some principle error. I should start from trapezoid roof of outer cages not their walls. The way, that I choose, led to nearly parallel edges (on pictures of AT-AT one can see that each edge should build an angle of ~10° with axis of roof).

On the first picture (copied from rebelscum) one can see how it's done in plastic (I thing that the picture shows Master Replicas model). Now the next picture shows my imitation of coupling and one nearly finished drive motor and one in parts.

As on the first picture you can see, the hips are quite thin. In original they were movable on both axis - this to motor and this to leg. As such during making step AT-AT was parallel to ground.

I couldn't afford to make such thin parts in paper and still hope to have them playable. I also resigned from axis on the motor.

Last picture shows my scheme. As usually multilayered implementation (this time quite thick ~1 cm). The upper triangle was added to glue whole assembly parallel to body.

Short update body with drive motors. I've forgot to add it earlier. The metal parts comes from broken computer HDs I know it's not paper. I did it just to have a good explanation of the question: what can one do with old hard-drive. Build an AT-AT !

First I made the internal framework of head and the side picture (mirrored). There should be place for some pilot inside and the top of head should be removable. The red line on the 2nd picture shows where I cut both parts apart.

The lower parts of sideboards were glued on the frame and the upper sideboards were mounted on the frame with Scotch-tape (actually Tesa-tape). Then I took measurements of all 5 strips that should build the roof of the head, and subsequently glued all parts together (sorry last picture is not sharp but I have no better one).

Head: before cutting out sideboards I copied them on Xerox and used these copies as patterns for 3D-finish of head.

The head was connected to body with Phi=37 mm tube (using 2 short chopsticks on each side).
Afterwards I painted the head in the same grey colour as legs.

Then... details, details, details...

I was looking on the pictures I collected earlier and I was trying to add all small parts on the body. As first 4 large shields on the front and back part of main body, then three panels pointing in the direction of head, then all 3 roofs and finally some attempt to make back side.

Finished.

As you see on last picture this particular AT-AT was sized by Luke Skywalker