Monday, 27 January 2014

Computer Modelling: Sketchup and Pepakura (2)

I've now finished constructing the simple basic model that I cooked up in Sketchup and Pepakura and actually it did not give me as much trouble as I thought it would. For the most part I stuck to the patterns provided and had little trouble getting them to fit. I think this may have been helped by the fact that I chose to work with fairly thin plastic sheet, which tends to negate the 'corner' problem that you can have with this kind of project; namely, how do you attach the pieces of plastic to each other? Do you do a simple butt joint (as in woodwork), or attempt something akin to a mitre joint i.e., trying to join the two pieces edge on with no overlap. It may seem a small matter, but it can make a world of difference if you get it wrong, especially with thicker plastic sheet and you could suddenly find large unsightly gaps, or ill-fitting pieces no matter how accurate your cutting.
With thinner plastic this problem becomes a minor matter, but you gain extra problems, namely a lack of strength and rigidity in your model. As indicated in my previous post, though, balsa wood can be used to brace the piece. Another problem is glue, go easy with it on thinner sheet as too much glue simply melts or distorts the plastic. It happened a couple of times on this piece, though it is not very apparent in the pictures, but I have since filled a couple of gaps and hollows with Plasto which I can easily sand back.

Friday, 24 January 2014

Computer Modelling: Sketchup and Pepakura

It's a brave new world and though in my model-making I'm dealing with solid physical objects, I'm increasingly aware that there are many sites and a great deal of software available on the web that can help me in my hobby. This ranges from the numerous online forums where you can get glimpses of other people's skills (and let's face it, hate them with a passion for getting everything so damned perfect with their creations!), sites that provide you with a range of materials, printables and instructions as well as a much wider choice of models and assorted stuff than was available in pre-internet times. No wonder so many high street model shops seem to be closing down.

Modelling in Google Sketchup.
There are also many computer modelling programmes that can be utilised by the model maker and, joy of joys, most of them are free. For instance, take Google Sketchup , a simple-to-use freeware modelling package which can be used to make 3d models of whatever you like. But, I hear you cry, they are but 3d models, pookas, phantoms, glyphs, electronic caprices without form or substance and that is indeed true unless you then upload your model into a wonderful little programme called Pepakura Designer This programme (also free unless you want to build your own models in it, which requires payment) was created with the growing papercraft modelling fraternity in mind and it allows you to literally 'unfold' 3d models into a recognisable paper plan, a bit like the dress-making patterns my mother used to use. These can be printed onto paper or card and then cut out for use. I have tried to make card models, but I find the material too flimsy. However, there is nothing stopping you from cutting out the individual pieces and using them to make plastic models.

I like science fiction and by extension enjoy creating the odd sci-fi model. I find, though that simple science fiction figures often lack a suitably sci-fi looking environment. With Sketchup models, Pepakura patterns and a little patience, though, small bits of sci-fi kit can be created from plastic card, other strip plastics and balsa wood. The model in the picture above was a simple design I came up with that would  look fine in any number of science fiction scenes, so I transferred it into Pepakura as seen below. In Pepakura, though each model comes in at a default size, the scale of the pattern can be altered to make it smaller or larger, though to do the latter you sometimes have to print it onto several sheets of paper, which would then entail an even lengthier process of cutting, fitting and taping the pieces together before getting started. I simply organised my small model to print out on a single sheet of A4 and that seems fine.

Making a pattern in Pepakura.

Before getting stuck in, stop and think about some of the choices Pepakura makes, though, as it can make things more difficult, such as with the front curve of the model seen here, which it thinks would be best created with numerous strips, whereas a single bent piece would work much better. Otherwise, though, crack on. The patterns can be cut out using a sharp knife or scissors, sprayed or smeared with glue (I use either Pritt or occasionally Photomount), stuck to the plastic sheet; the patterns can be peeled off later.  When dry enough I cut the pieces out and then begin to assemble them. Care needs to be taken at this stage to make sure the pieces match and that there are no major gaps or overlaps as these will only have to be sorted out later. Glue lugs in place to secure the pieces of plastic together, but never ignore that time-honoured modeller's resource, balsa wood, which can be used as shown here to add rigidity to what would otherwise be a rather flimsy plastic box. Balsa on balsa would need a good PVA (white glue), but balsa onto plastic needs something more resilient; I use a cheap soft plastic glue that I bought from Wilkinson's.


So far so good, the model is slowly changing from a 3D fantasy into something more tangible. The only word of caution is to be patient, building from scratch does take longer than from kit, let the glue dry thoroughly before moving on to the next stage.