About this Blog

This is about the combination of two interests, Radio Control vehicles and Science Fiction models. Its also about vehicle design. The models have to satisfy two main precepts.

1. The vehicles have to work, ie be driveable, but not nescessarily win any races or rock crawling competitions.

2. The main thing is that they have to look cool.

Monday, 13 August 2018

Moebius-1 part 1

I have started a new project, a spaceship model and one I have been thinking about off and on over the last 3 years or so.
I came across a concept sketch of a background spaceship called Flat Top from the original late seventies Battlestar Galactica series on the website galactica.tv a site that has a lot of interesting info on the original series. The sketch may be by Joe Johnston, it certainly looks a lot like his style, but is not signed so it's attribution is not certain. Here's the sketch below followed by the Flat Top model made for the show;

and for comparison here is Moebius's original ship;

The Flat Top in Battlestar Galactica is a particularly rough and ready model perfectly suitable for use as a background ship in the so called Rag Tag Fleet. It does not faithfully copy the two seater bubble  Moebius design but ups the scale somewhat making it a much larger ship.
As is my custom, I am not making a Flat Top replica but am freely interpreting the concept sketch in my own way. I rather liked the Moebius two seater configuration and the clear bubble cockpit so one of the first questions as to the feasibility of the project was to locate a suitable clear plastic sphere or more usefully a pair of half spheres. A couple of years ago I did eventually find some cheap domes on ebay in the form of dummy CCTV cameras at about 100mm in diameter. Scaling up the drawing I reasoned that the length of the craft was roughly 10 times the diameter of the sphere so a 100mm sphere would equate to a metre long ship. The scale works out to be 1/24 as I think I can comfortably fit two 1/24 scale driver figures into the 100mm bubble.

More recently I started on a rough 2D cad drawing tracing over the artwork scaled up to size in the free 2D CAD program DraftSight.

In both Moebius's ship and the BG Flat Top there is a single central support column that ties the flat upper part of the ship to the lower crew hull. This is one of the areas in which my interpretation of the concept sketch differs significantly in that I propose that there are two angled columns either side of the central spine that sits under the flat top section. In my view the concept drawing suggests that the column is in front of the large ribbed form and not in line with it. The other significant difference is in the shape of the flat top section. Again Mobius's original design shows a simple rectangle and the BG version follows suit. I am going for what I can only describe as a coffin shaped outline. 

One of the first tasks was to make a supporting armature that rigidly held the major sections together and provide mounting points and electrical power connectors. This I made using aluminium rectangular and channel section, 3mm aluminium sheet and 3/8" steel water pipe fittings. I did make an error in the angled cuts on the rectangular section. The angle struts are are several degrees too steep fore and aft but I should be able to correct this with the cladding.
As a TIG welder capable of welding aluminium is way beyond my means I used aluminium brazing rod. It goes under a few different names such As Durafix or HTS-2000 and only needs a propane torch to melt. Unlike a silver soldering process, the rods do not work with capillary action, the melted material will just bond with the surface and bridge across the joins much like welding, so to get a really strong bond, where possible, I will tin both surfaces first before placing them together and reheating them until the material on the joints melts and fuses together. This means you have to be able to precisely locate the two parts together where they need to join so they cant move whilst heating and joining. I drilled a small hole in the plate and the strut and bolted them together whilst reheating the joints. Once remelted I had to tap the parts until the melted brazing rod flattened and joined together. The solidified material on the pre-timnned surfaces takes up some thickness which the bolts are tightened against. Once it melts again the bolts will become loose so it is a tricky operation to get right. You have to scratch the rod on the surface to get the material to bond properly as this process removes the aluminium oxide on the surface of the parts which floats to the surface, increasing the bond strength. You can also use a piece of stainless steel wire to scratch the surface during the melting process. In fact you have to thoroughly clean the mating parts with a stainless steel brush before you start or the stuff will not stick. Any contamination from ordinary steel and the bond wont work at all.

The flat top surface is made from 6mm foamed PVC sheet with a stiffening spine of 12mmm aluminium C channel and a reinforcing bridge of 10mm solid grey PVC. Provision has been made for mounting on the top surface as well as the under hull section along with 12volt DC power connections. A second layer of 3mm foamed PVC sheet will be added to the underside so that the 3mm aluminium flat plate will become flush.

The main spine forms and under surface detailing will incorporate a number of charity shop toy parts I have on hand and some I have recently acquired. As an example here are a couple of recent charity shop acquisitions;

The large clear plastic part of the babys' toy on the left is being used along with a similar clear dome part to the one on the right. I don't know what this clear plastic is but it has a slightly rubbery feel to the surface, deforms without cracking and sticks with the normal solvents that cement acrylic, ABS and High Impact Styrene. It can also be sanded and painted just like the previously mentioned plastics.
Below is some preliminary laying out of the charity shop main central spine parts. From the rear the order of parts is as follows; half an acrylic wine glass, the clear dome from a baby toy followed by the baby toy part shown above, then dummy CCTV camera bases joined end for end and cut down, the inside of a plastic double walled drinking cup, two wheels halves from a WallE truck toy and then half of a strange Toy Story electronic TV game.

I was contemplating a few notions for the engines when I pulled out some bits left over form the first toybash truck project that used a couple of cheap rubbish truck toys. These are two front cabs with the roof, grills and bumpers removed and turned to face upwards.

Here's a picture of the original toy for reference.

 I installed two 12volt led light strips per engine which then get a screen of old fluorescent light diffuser in front and styrene strips glued over all the gaps  from the inside.

I also installed a switch on the top surface so I can turn the engine light off separately from the rest of the lighting. The baby toy shapes were made removable for access using a magnetic cupboard catch at the front. The magnet part was stuck into the clear shell using a lump of epoxy putty placing it into position until the quick hardening putty set. The rear has a convenient lip which fits snugly under the half acrylic wine glass at the back.

I have been playing around with the arrangement of the other large detail pieces to go on the underside of the flat top. These comprise parts left over from the bruder bulldozer and a transformers toy SCVNGR. There is also wheely bin from the rubbish truck plus the two green roofs from the cabs. Except for the central spine parts these are not yet glued into position.

The two orange ribbed tanks are the handles from the controller of a cheap motorised crane toy.

On the sides at the rear are a molding from an old washing machine with a section of disposable razor handle and a part from the WallE truck toy. The brown shapes in front of the green engines are also from the WallE truck toy.

It all looks pretty chaotic at the moment but once that grey primer goes on, somewhat down the track at the moment, it will all get a little more cohesive.

More soon...

1 comment:

  1. Thanks again for posting. The ship looks great so far.

    I've stalled out making a few of my own ships so I appreciate the detail you put into your posts. They inspire me to keep going and eventually get one finished.