Kawasaki Z400 - Kozin

[AlanG]

It has been a while since I posted a build - I have been relaxing with a series of small models, very enjoyable but of no special note.



Having had the disappointment of no new motorcycle from Yamaha this year (discounting the "pop-up cards" which don't really count) I decided it was time to attack the Kawasaki Z400 model from Kozin. This first appeared in October 2009, when he showed a preliminary CG image. Then nothing much happened until March 2010, when he started a new web page for it with a couple of rather more refined CG images. One or two more images appeared in May and June, together with two successive versions of the Pepakura model file. Through July and August we saw the progress of the paper model build to completion, but no updates to the model file.

Since then there has been nothing, and indeed updates to the whole web site have been very few and far between, though in December 2010 and January 2011 he was already showing images of yet another Kawasaki (750-RS).

So, I was starting with a rather unrefined Pepakura model, locked against modification, so the best I could do was produce a PDF file of the unwrapped parts and take stock. The resulting pages consist of a rather unstructured mass of black vector line segments overlaid on a bitmap containing all the colours and textures.



Here every straight line segment is a separate stroke, even the individual dots on the (frequently redundant) dotted lines. The way the parts have been broken up also leaves much to be desired - presumably it has largely been left to Pepakura's default algorithm, which clearly does not know much about "makeability". Even worse is to come:



Any offers as to how to cut and fold that one?

Alan

[Stev0]

Change the textures so that there are no saturated black colors. You can go with a dark grey for all the blacks. This way if you want the fold lines, they will be entirely black.

[AlanG]

Hi Stev0 - thank you for your comment. Changing the texture in Pepakura would indeed have been useful, but unfortunately the PDO file is "secured" against modifications. Pepakura Designer refuses to open it altogether, and selecting "Setting/Texture Setting..." in Reader just comes up with a box saying "Cannot edit texture of this file". I am not really familiar with Pepakura, though, so there could well be something I have missed.

Anyway, I decided to go with a vector editor, but am much too much of a skinflint to afford a recognised commercial product like Illustrator. I had already downloaded the open source Inkscape, though hardly used it, so I decided to give it a go. It was easy to move the texture bitmaps into a separate drawing layer, and then hide them, so that I could see the vectors. Then I could start joining them up into coherent shapes.

Well, it was soon clear that it was actually MUCH easier to draw a new connected path over the top of the original vectors. Inkscape has an effective snapping system whereby new vertices will snap to existing ones, ensuring the accuracy of the tracing. Once the outline is traced, plain-coloured parts can just be filled with that colour. Then tab outlines and fold lines can also be traced. The black splodge from my last post came out like this:



Some textures, like bolt heads and logos, I redrew with vectors. More extensive ones I cleaned up and trimmed from the original texture bitmaps, and applied as pattern fills. Finally I labelled each part using the Pepakura model display to work out what it was. The whole process ended up taking me about a day's work per page, and delivered pages like this:



Better, but clearly some parts would need changes to make them buildable.

More soon,
Alan

[AlanG]

First paper - the coloured bits from the first page.



I rearranged the side cover parts to join up the front into a single flat panel, instead of having a separate bottom triangle. The fuel tank is my second attempt, the first having been a disaster. For this try I separated the sides and the top from each other, constructed the sides and attached them to the underside first. Finally the top went on to link everything together.

It is quite a challenge to work out how to construct some of these bits.

Alan

[AlanG]

A major advance, or at least it feels like it! The major parts of the engine and gearbox needed a good deal of modification to make them buildable, at least for me. This mostly involved separating the complicated pieces into smaller chunks which can be assembled more easily, and then joined together. The Pepakura unfolding algorithm seems to put a premium on keeping each designed part as a single piece of paper, however complex.



The pieces come together to make a simple but plausible-looking engine.



I'm sorry about the poor picture quality - I seem to have been having an off day with my camera.

Alan

[peter taft]

I love this machine, and in your most capable hands, she will look splendid Alan

[Pat_craft]

Nice looking !

[AlanG]

Thank you for your comments, Peter and Pat. This model is certainly not in the same class as the Yamaha VMAX or Loudog's Mille Miglia, but I hope it will come out fairly recognisable.

The next stage is the frame. Again Pepakura attempts to keep far too much linked together as single parts. I rolled each piece of tube separately, then joined them up into the main (fairly flat) components using the Pepakura 3D image as a guide to get the angles roughly right.

The final assembly is always a problem, as the growing frame has almost no strength until the final cross-pieces are in place (and not a huge amount even then). Several of the joints got broken in the process, and had to be reglued.



Fortunately, the engine fitted in without too much agony, though it did need some packing underneath to get it to sit securely on and between the frame lower tubes.



Missing in the original design are the triangular brackets connecting the front of the engine to the front tube. These are quite prominent, so I drew up something plausible using photos of the full-size bike as a guide. They also add some rigidity to the front end of the frame.

Alan

[Zathros]

My brother-in-law had a Kawasaki and Suzuki dealership, which I helped him out at. I also was the Parts Manager at a Yamaha, Suzuki dealership. We would assemble the bike in the Spring as they arrived, and all through the Summer season.

Having built many of these bikes out of the crate, and having worked on many of these bikes, I wish to say, your build of this model is excellent. I didn't know these models had this much potential. I applaud you workmanship. And the picture you apologized about, wow, I'd like to see you on a good day. Great job!

[AlanG]

Zathros, you must know a great deal more about motorbikes than I do. I have never been interested in riding them, even all those years ago when I was a young man. I have just found that the models are oddly satisfying to construct. These models by Kozin are not the most complex - I suppose roughly comparable with the simpler Yamaha ones - but present a significant challenge because of their rather "unpolished" nature and lack of any assembly instructions. I surmise that Kozin himself must be a very accomplished modeller, as he seems to sail through the difficulties I am having.

Construction continues at the rear end.



The chain and sprockets were rather crudely drawn - very polygonal and with rather approximate texturing - so I added a new module to my model-customising program for drawing generic cycle chains. It probably doesn't make much difference, as the chain is pretty small anyway, but at least *I* know that the link shape and sprocket teeth are correct.



The back end is coming together:



Alan