More 3D moaning with Wooden Carriages, but it all works out in the end.

DB rails on from a post that was going to be yesterday's which will probably appear out of order in the next day or three, but since I've started on these carriages:

My next frustration with 3d prints is strata. When I dipped back into NZ120 about 15 months ago, I bought a set of 3D printed wooden carriages:

I didn't realise they were this bad until I had primed, painted, dulcoated, and then started washing them with some weathering. They certainly don't look great with a light shining off them that's for sure. Had I noticed this earlier I'd have sanded them down a bit. Which I did with the roofs, as there is a pronounced 'ridge' along the roof centreline and on the rounded ends. Fairly easily dealt with using a long thin fine file for the centre ridge (so as not to knock the roof ventilators which are nicely done, and fine sandpaper for the roof ends to give them a smoother-flowing shape where the curves join.    

These are fairly old prints now I guess, and new ones from higher resolution printers will be smoother... but having said that, I've paid for them, and there is now a much better one available. A bit like every camera and computer I've ever bought I suppose. 

My next grumble is is warping. It seems most 3D printed things that are shaped like a bathtub will warp - wagon sides and locomotives bow out like the below, and often they have a minor 'humpbacked' longitudinal bend. 

While most prints seem to have relatively fine supports inside in an attempt to counter this during printing and curing, they tend to snap and break off due to the warping forces. So why not make them stronger and more numerous? These carriages have this feature already, with some good thick cross pieces under the crown posts that tie the sides together. If there were two more located here (red arrows) the whole side would be nice and straight, and the truss rods wouldn't splay out and then pull apart: 

These structural tie-pieces would be welcome on my ZAs, and even the Wb loco (as the user can remove them many months later when applying a chassis - I note the DM print has these, which is sensible).

And my last frustration with the 3D printed stuff, and then I promise I'll zip-it (other than tomorrow's post), is the sagging of fine detail. This sometimes manifests itself in hanging edges becoming curved or scolloped (compare the scalloped underframe of the car-van in the foreground vs the ruler-straight sides of the car because I have overlaid its bendy bits with styrene, although this pushes them out closer to the red 'wooden' sides than I'd like:

Fine unsupported rodding often sags too, such as on these Shapeways Z tanktainers:

Presumably this is from a lack of supports, or maybe it happens during curing. 

So you have to cut off the offending bits, and then due to the material's brittleness, even more bits snap off. Maybe its time to accept that 3D isn't yet ready for this type of fine detail yet and it could be omitted, with slots or holes left instead so that we can put these details in ourselves using straight plastic or brass rod. 

I used .030x.030 plastic square rod to replace the broken and bent truss rods to match the existing printed rodding, but in hindsight, looking at some prototype pics afterwards,  I should have used much thinner brass rod and done all six carriage sides.

Enough moaning. These carriage bodies look ok from 2-3 feet away. Arguably the finescale MMW ends and bogies make everything else - carriage bodies, couplers, track, buildings, other rolling stock, ballast and scenery, look horribly chunky.

Bogie screws and couplers are yet to be figured out. I added battery boxes to one of the cars and immediately took them off because they looked silly. Now after dredging up some prototype pics, I wasn't actually that far off so will re-add them. I also need to do something about glazing the guards ducket. Or replacing it with the modern pressed steel pattern.

-----The next day:

I pulled out some Microtrains and Peco couplers to fit the cars with, but with the bogies having cross pieces at the ends that I didn't want to fiddle with, couplers would have to stick out a long way to clear these.

So I started playing with the 'sprue' of the MMW parts, cutting an L out of the corner and putting a slot in the end of it. This was three small holes joined up with the help of a knife and some files. 

And this made up a simple hook-and-eye arrangement:

Note also the white .040x040 rod bearers added to the bolsters of the cars to encourage upright running in the above pic. These were added at one end of each carriage.

In testing, the cars negotiate the tight curve behind the roundhouse and the 'S curves' of the pointwork at Studholme whether pushed or pulled. Those are large radius turnouts, so perhaps they would struggle on medium radius crossovers, but I'll leave that for some future experimentation. 

There is also a tiny bit of play in the bogie mounts too which can't hurt. After wondering how I was going to attach the bogies, I ended up using small flat-headed nails that are about an inch long - the points of which have been liberally contact-glued to the underside of the carriage roofs! Seems to work...

The below was a first cut at carriage steps - a plastic one glued to the underframe, and bits of MMW steps attached to the corners of the bogies.

These didn't last long and were replaced with folded up MMW ones attached to the frame, shortened and mounted a fair way outboard to clear the swing of the bogies on curves.

A little weight was added underneath using nails. Keepin' it classy, NZ120. Bogies have been mounted, and steps are in place.

As afterthoughts, I 'painted' a loo in using some white styrene behind the windows, added the centre (ventilator?) (top-middle of that red sides) which might also be loo-related, and steps under the baggage door on the van. I should have done the rain strip on the roof above the baggage doors, but that would have upset the weathering that I'm pretty happy with.

Battery boxes were re-added - these had to be very thin styrene because the truss rods are so far outboard. Painting everything 'weathered black' helps disguise the inaccuracies.

And as a final touch, the circular number and class plates were also carefully painted weathered black. These are quite prominent on most of the pictures I've seen, so I painted little yellow 2s to signify second class. This was done with yellow that had a touch of dark included. Then to further lower the contrast, a blob of Tamiya 'smoke' was placed on top. Another blob may yet be applied...

You can see how far the Microtrains couplers had to stick out on the ends to clear the bogie frames, but my homemade couplers give a really nice 'close coupling' effect between the cars.

I don't know much about carriages, but I assume these are 47-6 ones. Not even sure if they operated on the Coast or on the Waimate Branch, but most importantly, they are red, so will look the part behind a DJ or a tank engine or at the end of a mixed train. When viewed from the rigorously-enforced mandatory minimal viewing distances.