ok, so I have questions, not trying to nit pick nor will it stop a purchase either, but
1. Is the crackle pattern exactly accurate or did you modify it slightly? I though I read that it was slightly changed earlier in the thread, but wanted to make sure.
2. Since the slider channel is shorter does that mean it is a little shorter than the real one when fully extended?
Hi, yes we had to change it slightly. Basically we took about 20 pictures of the real prop as square on to the camera as possible and each one rotated by one 20th so as to cover the whole body. Then I put the images into photoshop and corrected them slightly for perspective and stitched them together to make a flat image of the crackle glaze pattern. Then I imported this into Illustrator and drew round every crackle. Not just with one line though, because the cracks are all different widths, so I traced round each crackle "island". We had always decided to make a slightly idealised version of the real prop without the screws that hold the main body to the top collar and the tail piece, as we didn't need them and also in the prop they are painted, which we assumed was to try and hide them, so we felt that it would be ok to leave them out. This meant that I had to make up some crackles to go over where the screw heads are in the real prop. They are quite big screws for the size of the prop (about 3 or 4 mm across). So in those areas the crackle glaze is made up.
Then we had a metal block made with the crackle artwork etched into it to make sure that the pattern didn't look stupid, took a paint coat ok and also to work out the correct depth of etching. (note: etching into a mould is a different process and makes the crackles look different to the way that real paint cracks that appear during the paint process, in that the side walls of the crackle lines have to be sloping in a vee shape rather than straight sided, which means that for a given width of crackle line, there will be less grey infill than on the painted version, making each line look smaller in the moulded version for the same width.)
I then rubbed white emulsion paint into the cracks to see how well they performed in terms of look and paint retention. Earlier on in this thread you can see images of that test block (post 240, page 10) and how it was used by AngelusLupus and AnubisGuard to make a 3D rendering of how the main body might look with the proposed crackle pattern on it.
As a result of this work and the metal sample, I decided that in a few areas the crackle effect needed simplifying and so reduced the number of crackle islands in some areas and along the edges to make the crackle pattern a bit more distinct as I felt that in places it was so small that we were at risk of losing the pattern in a mush of tiny grey lines.
So that's the long crackle answer. In short, overall fairly accurate, simplified in some places and invented in two main places where there were screw heads in the original.
As far as the extension goes, I'm not sure, but I think that the extended sonic is about the same extended length of the original... sorry, shocking that I don't know this exactly. The slider and the extended length are more a factor of the electronics that we had to squeeze into the product, but we aimed to be as close as possible to the full extended length of the original, given that we wanted to be exactly the same as the original when retracted.
Hope this helps.