Emboldened by my success in drawing the artwork to etch a set of replacement rods for Canopus I moved quickly on to something a lot more complex; the etched parts to complete the Hudson-Hunslet diesel locomotive.
In retrospect the connecting rods were easy to draw. Not only are they a fairly simple shape, but they are also the same on both sides, so the artwork for the back is the same as for the front. Also all four are obviously the same so you only need to draw one. The parts for the Hudson-Hunslet are a number of magnitudes more complex. Not only are some of the parts quite complex shapes (i.e. not a simple combination of rectangles and circles) but every single part needs different artwork for the front and back of the etch, plus some of the parts fold. The flat parts took a while but by far the most complex was the single piece that wraps right over the loco to provide the body panels at the drivers end.
I took a similar approach to designing this part as I have done metal pieces for previous models. I started by drawing out a part that I thought would work, then printed it out, stuck it to some brass, cut out and folded the part and then checked to see if it would fit. On the third attempt I ended up with this.
Designing this folded part was especially complex, as what I had was measurements for the inside of the part, but it is much easier to draw the part if you know the outside dimensions. It's fair to say that it was very frustrating trying to get this right. It seems to be a good fit, but I'll only know for certain when I try and fit the etched version. The final artwork measures out at 62.56mm by 35.02mm yet contains 15 different parts (some are spares and some are variations) so some of the parts are going to be devilishly small.
There will now be a bit of a pause in posts on this locomotive while I await the etched parts and the next set of prototype 3D printed parts.