Tuesday 25 January 2011

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Fig 1. Vostok1 plans
 In order to build an historically accurate model researching every detail is important and much harder than I'd anticipated. I've found hundreds of images claiming to be Vostok1, yet no two are alike! None of the images or plans show every view of the capsule. The best (and what seem to be most reliable) plans I've sourced for shapes and very basic dimensions are show in fig1 so I am having to draw and scale my own plans with dimensions of each component (and 3D CAD models) in order to visualise and build from.
The project is a puzzle and not dissimilar to a restoration project. The Vostok restoration raises unusual issues due to the Designs original secrecy, a great deal of speculation over 50 years and for it's unrecognisable condition on returning to earth meaning a lack of concrete image documentation.
 
Figure 2. Vostok Computer generated model
  Fig 2 (left) Is my second Rhino sketch model with scaled dimensions to work from. I collaborated and scaled 3 photographs and the plans in fig 1 to use as bitmaps to generate the model. I can use this to begin the making.

Fig 3 (below) is Chemi-wood (kindly donated to The Arts University at Bournemouth by Force India Formula1 model shop) which I have turned on a lathe with digital reader for precision (working from dimensions taken from CAD model.) I built a Mandrel from aluminium to give a 50mm clearance between the chuck jaws and the chemi-wood.
 

Fig 3. Vostok lower cones
                                                                                 
Fig 4. Feld-Grau Cellulose paint

Fig 4 (above left) is a tin of cellulose paint bought to spray the green/grey colour apparent on the capsule.There is much speculation and debate on the actual Vostok colour but after research I discovered what I believe to be the correct colour. The colour is FeldGrau which is likely to have been used on the upper cone of Vostok1

Fig 5. Acrylic Hemisphere Vacuum form samples

 I sourced acrylic hemispheres for the Vostok sphere. The closest I could buy was 4mm in diameter too small so I vacuum formed them with 1mm styrene twice to bring them up to size. To create the hatch (2main hatches) detail on the hemispheres I Vac formed again  and cut two circles from this styrene form in the correct position (mapped out first on a transparent form) for 2 hatches to stand a little proud of the main sphere. For the 'false' hatch I cut away 1 circle from the main sphere and replaced it with a smaller one to create a subtle gutter.
Fig 6. Jig for pillar-drill holes every 12.41° 
The fixings around each hatch appear to be welded divots as opposed to bolts. I mapped them out in Rhino and built a jig to use on the pillar drill to ensure even drill holes at every 12.41 degrees. With the discs being hollow domes they
wouldn't drill easily so I filled the inside with car body filler before drilling for rigidity.








Fig 7. Master for Vacuum forming mould

Fig 8. Car body filler test cast
Fig 8. (left) After Vacuum forming the master I made a quick tester using car body filler. I tested one aluminium finish method with a metal cote paint (high metal content paint). Which proved pretty effective. I will also test with aluminium powder cast into resin. As you can see at the top of this hatch, the Vacuum former melted the styrene. I will re-make the hatch using the jig and make a silicone mould.







Fig 9. Plaster Mould with base and styrene master
 Fig 9 (left) Plaster cavity moulds to pour silicone mould from master. MDF box built to ensure hemispheres are level. Plaster jacket to maintain the shape of silicone mould.


Fig 10. Cavity moulds filled with silicone


Fig 11. Resin Cast from Silicone Mould
 Fig 11 (left) shows my first attempt at a fiberglass cast of each hemisphere using the Silicone mould. The metallic finish was gained by using 1:1 ratio resin and aluminium powder (with extra powder dusted into the mould). Where the dusted powder was not saturated well enough in the resin the cast is easily chipped around the hatches. Another attempt is catalysing at present, this time with less powder dusted in the mould and a 1:2 ratio of resin to powder. Although I am actually pretty keen on the 'rustic' finish, it seems more genuine and less 'like a model'.


Fig 12. Vostok computer generated model (radiator panels)

Fig 12 (above) is my Third Rhino render of the Vostok with radiator panels (on the underside. I built a second 1mm thick cone over the lower cone and dived it into 32 individual panels (each 4 make up one section) Once I'd drawn the detail and worked out the angles of the concertina, I then unrolled the developable surface of each panel to flatten for use as vectors to be laser cut. No etching facilities but intend to use 1mm acrylic and use high metal content paint to finish. Failing this I'll laser cut thin aluminium mounted on card/acrylic. The panels do not need a high gloss finish so the Metal cote paint should work fine. 


Fig 13. Final Hemisphere casts and main capsule body (background)


Fig 13. (above) is the final sphere cast hemispheres. I'm pleased with the finish and durability. The casts are 3 parts aluminium powder to 1 part resin painted in coats into the silicone mould. The image in the background is the acrylic spheres sprayed with the Feldgrau paint and pegged into the upper cylinder of the Capsule.
 
Fig 14. Vostok lower cone with radiator panels



Fig 15. Vostok with bands




Fig 16. Radiator panel etch drawings


Fig 18. Capsule with porthole
Fig 17. Milled Aluminium banding             
                                                   Fig 19. Banding     
                                                                       
Fig 14. (left) shows the lower cone with radiator panels. I drew the panels in Rhino working from bitmap photographs. I lasercut the 32 individual panels from 1mm acrylic. Once i'd worked out the correct position of one set of 4 panels I plastic welded them in place and cast the underside in plaster to use as a jig for the remaining 7 sets of 4. I sprayed the panels silver and just need to attach them to the lower cone. (sprayed silver with a little matting agent). I'm not keen on the finish and intend to draw up some new vectors to have them etched in Stainless steel...Fund dependant!

Fig 15. (left) shows the Vostok sphere cut and positioned on the upper cone. I've cut aluminium strips for the bands cradling the sphere. For the little bands cradling the gas bottles i have pressed steel wire and used a 0.6mm drillbit for the holes on each band. Jewellery wire is glued in place between the two drill holes. Some Respraying needs to be done on the upper cylinders to get the correct colours. I also intend to take a silicone mould of the lower cone enabling me to create the same aluminium powder finish as the sphere. Although once the radiator panels are attached, not much of this cone will be visable but I think this will make a big difference in quality.

Fig 16. (left) are drawings for Etching the Radiator panels. I think having them in steel will give a much cleaner finish and add authenticity. Money was a problem so I researched into etching myself....very keen on this idea, however, don't really have enough time on this project so i'll send them off to PPD Ltd for professional etching. Payment for work I did at uni has fortunately covered the costs. I doubt the etchings will return in time for the project deadline, but I intend to keep working on the model post deadline anyway.



Fig 17 (left ) shows an example of several aluminium bands that will be fixed around the Capsule. No image I have found of the Vostok shows this drill hole detail from every view so I had to use laws of perspective to make an educated guess at how many holes surrounded the diameter. I used a mill to drill 6 x 0.5mm holes every1.52 mm (then 4.65mm space between each set of 6) across the top of a squared piece of aluminium- I cut the strip afterwards



Figs 18 and 19 show the capsule with porthole detail. I used hand drills to drill into the resin casts...very carefully as unsuitable shape and position for clamp or jig.I plugged the holes with lathe turned aluminium tubes leaving a fine lip around the top for tidiness. The tubes need to be backed with some clear acrylic to represent the windows of the portholes. I worked out the positioning of the portholes and extra detail using Rhino, 15 drawings laid out on the floor, calipers, compass, string and patience!
 Tomorrows action plan is; AM make silicone mould of lower cone.(cast early thurs) PM lathe remaining aluminium pieces, Respray the mid cones, back the port holes, assemble and begin working on wires and boxes on the lower middle cylinder.