DB says: So this lasering business isn't all beer and skittles.
The early-prototype ZG CAD from Marks Model Works is designed to be cut in 1mm (.040 inch) styrene. This is thick stuff and it doesn't laser easily, requiring a fair few bleams of power. I got mine back with one and a half attempts on the one plastic sheet... neither perfect with lots of scorching and melted sections and some parts printed over the top of other ones.I thought the whole thing was unusable due to the overlay, the general meltyness of some of the thin sections, kerfs and ridges on each side of the cuts. Yet for some reason I was compelled to poke out some of the parts yesterday for a look and ended up making up the whole model in a couple of hours.
Rating: Very, very impressive and well thought out. But not a walk in the park. Well, not the way I went about it...
I found it hard going at first, but fairly quickly was able to figure out that this has been designed as a very precise piece. Thus if I filed down the ridges left from the laser cutting and I scrawked out the slots with a modeling knife, it all went together very easily. As I said, its very, very well thought out, with internal bracing and ends built up in multiple layers as you can see from the pic above.
I've made a couple of suggestions to Mark re the underframe, bogie and coupler mountings, and these may make it to any future editions.
On top of the general messyness of the lasering work, the laser guys had also forgotten to do the 'partial cut' raster layer, and this has the fold lines for the doors. Bummer, as the doors are quite important on ZG models. I used bits of the supplied stuff and some plasticard strips to build the doors up and think they turned out ok, albeit not as straight and flat as they would have had I used the parts as included...
The ZG and little brother ZH are challenging prototypes. The doors are large fibreglass items, so in an attempt to get that look, I skrawked, puttied, sanded and then airbrushed on some white paint. This is the first time I'd airbrushed anything in NZ120 and struggled to find any white paint in my stash that wasn't effectively 'clear with a tint of white'. Old pals Mr and Mrs Humbrol came to the rescue with Gloss 22 White - finally, a white paint that has some coverabililty mixed into it. That skinny wee centre bulkhead between the doors is a pain to paint green, but the ends and bottom door roller channel weren't too bad. I used some Testors in a Brunswicky-Green shade and my old fave Acrylic Gull Gray on the roof beam.
Because of the amount of plastic that goes into the model, the thing is actually weighted quite well for NZ120. I added a couple of shotgun pellets between the main beams for a little additional weight just in case. Bogies are MT (they could be anything as they are almost completely hidden) and I whipped up some decals following the recipe supplied in a great Oct 99 Model Railway Journal article (incl NZ120 plans!). Although I'm guessing Tranz Rail, or whoever they were then, put a bit more slope on the 'R' than the standard Garamond Italic provides.
There is a nice side-on colour pic on page 61 of the March 98 Railfan. ZGs suit most layouts from 1993 onwards although I've never seen one on the West Coast - but that doesn't mean they haven't been there - maybe one of or more well informed readers can answer that one. They seem to use plenty of ZHs on the coast (the smaller ones built on ZA underframes and with blue ends rather than these which were built on UKs and have green ends).
OK, so my rendering of the MMW ZG isn't perfectly straight in some places (although to be fair I hadn't noticed until I saw these cruel close-up pictures on my laptop), but its not completely awful either.