Stage 3 -
Fabricating the
Armature
It goes without saying that for a model of this size an internal armature is absolutely essential, and that armature would need to be strong enough to support the model (particularly that huge saucer) for many years to come, but light enough to allow relatively easy transportation and handling. Further complications arose from the nature of this project – since we were dealing with casts of the original filming model, the aim was to build this replica as if it were a filming model too. That means multiple mount points on the model, and therefore even more structural strength, as the original could be mounted from several points on the saucer…so this one would have the same!
Original 4 footer at Image-G
The original 4 footer's armature. Fabricated in just a couple of days by Christian Colquhoun...!
In total, there would be four different mount points – the main one going into the keel, one at the main shuttle bay on the saucer, one underneath the bridge area on top of the saucer, and one hidden by the captain’s yacht underneath the saucer. This meant the armature had to be extremely strong at the neck to be able to withstand the weight of the secondary hull and nacelles being suspended from the saucer, with more structure than might otherwise have been needed if it were being mounted from the keel position only.
Upper saucer mount point on the original 4 footer, concealed under the removable bridge module - see the dark outline?
Lower saucer mount point on the original 4 footer, concealed under the captain's yacht area
Main shuttle bay mount point on the original 4 footer, concealed under the removable door.
Main mount point on the original 4 footer, at the keel. This cover panel fitted pretty poorly...!
Aluminium satisfies all the criteria, being very strong and very lightweight, and relatively easy to machine, drill, and cut etc. A central core based around a 40mm square mount post was constructed from heavy-duty aluminium billets, which would serve as the foundation for the rest of the armature to be built off. A central lateral plate was cut and profiled from 3mm aluminium plating to match the footprint of the upper secondary hull part, which would run through the horizontal centreline, going all the way back to the nacelle pylon wing and eventually curving upward to support the nacelles. A large section was left open at the front of this plate to allow for the deflector housing, which actually encroaches into the internal space quite significantly. The penetration point for the mount post was placed in the same general position as the original filming model - right behind the ventral phaser strip. This position lines up perfectly with the internal void of the dorsal hull above, enabling the post to pass through the secondary hull and reach all the way to the top of the dorsal, making it extremely strong and stable.
Marking out the billets for "the core"
The footprint of the upper secondary hull, traced out and laid onto 3mm aluminium plating
The assembled core and secondary hull plate, on the post of the first time
Underside of the core, profiled to match the contour of the keel
A good look "down the barrel" showing the core and foundation plate
The core extends into the dorsal void, allowing the post to reach all the way to the top
Side view, with the keel removed. You can see the ghostly shadow of the core inside the dorsal hull void.
To support the weight of the saucer, the core was skinned on either side with 6mm plates, profiled to make as much use of the internal void of the dorsal as possible and built out internally to create as much strength and upper surface area as possible to act as the foundation for the eventual saucer armature structure. A long, 8mm thick plate was used to act as the “spine” of the saucer armature, and perpendicular cross-members were added top and bottom at the port/starboard centreline of the saucer, braced with some machined supports. The upper and lower saucer mount points were built from 12mm thick bars and carefully positioned to be directly below the surfaces of the fibreglass parts using various pieces of structure.
Core structure being built up to create the foundation for the saucer attachment
Saucer foundation...taking up as much space as possible!
Very first "dry-fit" of the major hulls over the embryonic armature. Notice the cut-outs for the upper mount points on the saucer
Saucer "spine" plate, lower lateral spars, and bracing plates, ready for bolting together
Checking positioning of lateral spars
Upper lateral spars now in place
Perimeter panels in place, along with the lower saucer mount bar
Upper saucer mount bar bolted into position
Side view of armature, almost complete
A lot of trial and error went into getting this structure all figured out, as the physical features on the saucer fibreglass parts didn’t line up exactly above/below each other – the bridge wasn’t directly above the captain’s yacht along the Z-axis, they were slightly off-set from each other, so the structures for the mount positions had to be placed accordingly. Large plates were cut and profiled to match the flat area round the lower saucer outer perimeter, and further bracing and reinforcement was added where-ever possible. The saucer armature was designed to remain removable, to aid handling during the next stages of construction of the model.
A look at the neck/saucer connection. The saucer armature was designed to be removable to aid handling during the next stages of the project
Close-up of the upper mount structure
Close-up of the lower saucer mount structure
"Windows" cut into the secondary hull plate to reduce weight and improve interior light distribution
Dry fitting of the main hull casts over the completed armature, mounted from the keel position
Mounted upside down from the main shuttle bay position. The post socket is bolted directly to the saucer spine structure
Another look at the shuttle bay mount point, with the upper saucer cast removed
Mounted to the lower saucer position. The armature is rock solid, and more than capable of holding the model from this mount point. The post and timber base plate didn't like this very much though...!
With the bulk of the armature complete, it was time to start installing the lighting system and moving forward with assembling the fibreglass casts…coming in Part 4!
