Balls of Cement - URC Sputnik Wagon

 DB says:

I received a care package from 3 Foot 6 models yesterday. 

There are some impressive items within it, and I'm pleased to say that the quality is superb. Lewis mentioned a few months back that he has changed up his processes and the results really show here. No strata! Flat surfaces! Straight edges! No sags! Even the resin seems slightly less brittle and a little more forgiving, unless you drop something onto concrete from a height that is...

But more on that in a moment.

Its been a while since I have 'made something' with wheels, so why not let 3'-6 do most of the work and I'll finish things off. 

A prototype that I've always wanted is a cement wagon or two. There were two main bogie tank styles - these spherical Sputnik URCs, and the UBCs that came with either spherical or flat sided tanks with more conical tops. These are appropriate from the late steam era through until the mid 1990s. 

Here is a URC laid up at Taita in the early 90s.

The 3-6 one, which I believe was designed up by Simon Lister, is a Sputnik type. So that's what I'm making, and handily I have the picture above. There are a few wagons preserved too:  https://www.nzrsr.co.nz - search for URC in class. One has a picture showing the piping on the other side. There is also one UBC of the other shape preserved. David Mac's rolling stock register is a great resource for remembering what older wagons looked like without having to go and see them.

The 3D print quality here is great. Despite these being spherical surfaces, there is no strata at all on this print, the tubs are smooth and completely free of facets, the flat surface of the wagon top is completely perfect. There is not even any warp in the sides or the truss rods, or in the width of the trusses. The only slight blemish is in one of the corners, but its so minor I'm not going to touch it. There is a slight ring around each of the four cement balls (in the top half). I'm not sure if this is intentional from the design or a slight printing defect but I gave them a quick ineffective rub with some fine sandpaper that must have last been used on something yellow.

The four lids were glued on top, as these are printed as separate parts. I needed to open up the holes for these slightly in two of the balls. 

Then I did my usual removal of coupling pockets and shortening the bogie mounting points so the wagon will sit lower.

About this stage I managed to drop the whole thing onto the concrete floor. I can never manage to hit the little carpet mat under me and am finding such fumbles are one of many perils of getting older. 

The terminus of the dropping motion all but snapped the frame in half and removed two of the balls. Bugger. Some glue had it back together in short order. I put some steel wire (my point rodding) under the wagon floor to keep things together and flat.

I then had the clever idea of enlarging the two central holes in the bottom to fit some chunky short steel screws into. This would add some much needed weight to the wagon. I very slowly and carefully drilled these out to the required size, being careful not to damage the truss rod cross braces. This took a while at very slow RPMs. After all that care, I realised I'd need to remove the cross pieces anyway to fit the screw heads. D'oh.

The cross pieces were replaced with some thin styrene strip. The above pic shows the underframe with its removals, additions and repairs.

Then the action moved topside. After a 'first coat' of painting, I added the two platforms between the sets of tanks out of some scribed wood that was lying on my desk, and some ladders which are Marks Model Works CB ladders, some of the most useful things you can buy. I've can used these on many models. If they were a little longer and I was a little smarter, I might have tried shaping them better and making the nice hoopy bits on the top. I could have used some brass wire here. Maybe I will. Nah, that's never going to happen. 

But some .020 Evergreen styrene rod made some pipes on the deck, and along the side that doesn't have the ladders. 

And then it was time for paint and weathering. The base wagon is flat black, and the tops Tamiya Royal Light Grey. Weathering was a little brown wash on the truss rods, and on the top some pale grey Vallejo Game Wash and white Jacquard Pinata Alcohol Ink wash, running from the top down, and concentrating on the top half of the spheres. A little rust was dabbed on in places too. I may go back with the white ink at some stage, but then again its a subtle effect and I will use these on trains at their 'early to mid-life'  - either 1960s steam or behind 1980s DJs. So before they got really scungy.

The wagon was shod with some Kato Japanese 'Taki' tank wagon bogies that were reviewed here a decade or more ago. I used these rather the usual than MicroTrains ones because I will be running this among four-wheeled wagons which have Rapido couplers, as do these bogies. These also have a longer wheelbase and slightly larger wheels than the MT ones.

Sometimes the manufacturers, Kato especially, make spare parts available when they rerun certain models, but usually in limited numbers. I put these bogies on my Hobbysearch Japan wish list quite a while ago, and also some bogies that might suit a 30 foot guards van. When they all briefly showed up as orderable recently, I snagged a few sets and they arrived a couple of days ago. As this is typed, I'm not sure how much they cost.

The final touch, done after these pictures were taken, was to spray a little Dullcote on. The mysterious 'rings' on the top quarter of the tanks show up a bit in the photos, but aren't that noticeable when you're staring at the wagon going by. The Dullcote may help too. The bendiness in the second to last pic is due to the phone wide angle/close up, not any printing problems! 

Other than waiting for things to set this was a pretty quick project, taking about two hours up until the weathering.  

The most tricky job with all these resin bogie wagon prints is getting the bogie mounting points to take screws. I'm not sure what the perfect answer is here as different bogie manufacturers require different sized screws or mounting techniques. Every screw I've tried on a 3D print has trouble biting into the tough resin, even if you enlarge the hole very generously. And sometimes the mounting piece will crack or break off while you are doing this, or you end up damaging your nicely detailed wagon. 

What worked with this URC, on the third attempt at enlarging the holes, was discovering that I own a small 'tap' which scours out a thread inside a drilled hole nicely. Its not quite the same thread pitch/type/size as the small bag of metal bogie holding screws that I've used forever (seriously, they need a straight screwdriver bit if anyone can remember those). But the tap will gently and efficiently remove enough material that the screws seem to find a home reasonably well. I must find a handle for it rather than using pliers. Perhaps it would fit into the handheld pin vice thing I use for small drills. So if you have this issue too, you might consider going to one of the local engineering firms with one of your screws and get the right sized tap. They aren't terribly expensive and will last a lifetime of making 3D bogie wagons up.

Its a cute wagon. Something quite different in a train that's for sure. Highly recommended.

The southern branch of MD will be away over the hills for the next week doing research in the field.  

¡Hola! The 3-Foot 6 DM Class - 1

DB puedo hablar un poco de español:

Despite having one of these prints on my bench for some months now, it seems I'm going to struggle to get it into service before the real thing. 

Initial thoughts on the print: 

It looks waaaay overscale when placed next to my model DXCs - too tall and too long. It seems it's not, the real thing being a lot bigger than we are used to! 

Great detail - the difficult cabs and front end are well represented, even the front handrails are there. The roof details are pretty good too, although some are quite subtle and may vanish under a coat of paint. 

Further investigation:

After the real DMs arrived here and were seen in the flesh, it appeared like they would be a very challenging prototype to model. The sides are very detailed, and the prominent black rubber joins between the door panels will be really hard to paint and imagine applying the decals around these. 

There are also differences between the shell and prototype in the side door panels, especially those close to the cab, and on one side of the loco (the 'upside down' side in the image below) which has the square dynamic brake inlets. Not that many people would notice any of this. 

So I decided straight away that my sides would be photo overlays printed onto glossy paper, a la Ken Devlin Specials.  I spent about three hours one night building up the sides from photographs. This required perspective correction, scaling, colour matching, and - for the other 2.9 hours - removing the complex side handrails from the photos.

If anyone wants this full size (about 4000x4000 pixels) you can email me at the LinesiderNZ email. Maybe Lewis might host it on his website as this will get compressed. 

I took the file down to the print shop, printing it on the same paper The Linesider uses. The first page looked too magenta, so a little green was added, and by the third copy it looked about right. Even if you take the same file to three proper commercial printers, you will likely get three subtly different hues depending on what paper, ink and model of printer is being used, and the temperature, humidity and even whether the printer is warmed up or not will affect tones, which are basically dependant on how the different colours of ink (cyan, magenta, yellow and black, or sometimes red, green, blue) are absorbed into, and layer up on, the paper. The things I've learned over the past few years.

With this done and laid over the top, it made obvious a few shell issues which will likely be corrected in a future iteration of the 3D model. Primarily that the radiator section (roof fans and 'union jack' sides) is a bit close to the cab at that end. This also pulls the adjoining chunky roof section over the engine/SCR unit  (with its four 'feet') a bit further off-centre. 

On the side sills, the circular lifting lug holes are also slightly misplaced. This is what made me initially wonder whether the shell was overscale, because the bogie centre spacing was one of the few prototype measurements I had when the shell arrived. I'm not sure I will remember to move them...

The panel-side details aren't going to be a problem, as I'm going to be using my paper overlays anyway, but I will need to move the roof fans to sit over my union jacks, and this will require moving the engine room roof as well. I'm also tempted to make the roof a/c units more prominent, which will make them easier to paint.

Into Surgery:

The first thing I decided to tackle was to slightly alter the cab roof top corners. These are angled (as modelled on the shell) at the 'back' corners to give plenty of door height access into the cab, but at the front, the real thing transitions to a more rounded shape. A little filing sorted this.

When viewed from above, the front face of the cab should also curve a little more at the corners, rather than having a bevelled join. I had a little crack at this, but not in the top-right corners (when viewed from the front) where there are a nice handrails printed. 

The 'cowcatchers' were also subtly modified at the bottom. There's not much to fault though, as the very complex cabs have been modelled well.

After the pic above was taken, I also opened out the bottom of the coupler pocket to take MicroTrains couplers - another message to designers - every 3D printed coupler box I've ever seen has needed to be enlarged.

The roof fans and engine lid were moved about 5mm towards the middle (I was also able to move my sides slightly the other way to meet them!).

So in summary, you could well say none of this surgery really made that much difference. 

And below, with filler added, ready for painting. 

First few coats badly sprayed:

LC wrap up

 DB finishes up:

A bit of paint, weathering, coal and decalling has this batch of LCs (10 of Lewis H's latest model and two of the older prints) added to the coal train. My homemade black-on-white laser printed 'Lyttelton coal traffic' decals somtimes exhibit a little cracking at the edges if they are cut out with a less-sharp knife, and then some white shows through, so most of that was touched up with some flat black paint.

One of the neat features of the latest iteration of the 3-Foot-6 LC is that, because it is downscaled from an Sn3.5 model, it has a lot of really nice fine detail in the doors, end handgrabs, and a footstep at one end. Picking the last two items out in white really makes the wagons look nicely detailed. I need to add a few handbrake levers at some stage. Something that might be a good thing to etch.  

Recent efforts with the Trackgang whitemetal kits and 3-Foot-6 3D-printed ones have eradicated my early 1990s bog-cast resin ones from service, leaving me with a pretty good looking decent-length classic 1980s Midland Line coal train. When you add locos, guards van and the little protective XP or KP in front of it, it is about 2.1m long, or as long as the Studholme loops will take. 

The train looks pretty good. Hardly finescale, but its uber-Bondscale quality. 

I'll probably add another 5-10 of Lewis' next version, as I'd like to have the option of having an even longer train, plus having a few extras to drop into normal goods trains. And it sounds like a few LAs might be on the cards too. 

In summary, with no naked-eye visible strata, these latest LCs take the 'Nicest 3D Print That I Have' title away from the ZAs, and with the addition of new floor mounting points and some interior door lines, they will be just perfect. As Lewis says "the beauty of this tech is we can constantly and fairly easily iterate our designs to improve them"

And all credit to him for not only making these models available to the NZ120 community (filling the void left by the demise of Shapeways) but continuing to improve them; and to the earlier pioneers of 3D printing whose designwork have enabled this. And in the days before 3D, lets not forget Russell Jones' Trackgang (and Pat Eade's earlier Trackside) - all of this had made NZ120 a more viable scale. Three cheers for the suppliers!

Are we there yet? Taking Stock of 3d Printing with some LCs

DB completes the 3D printing review with what was to be the opener in the post...

I've had quite a few purchases from the Lewis Holden Printing Factory on my workbench for a while. Some for well over than a year now. So lets look at a few frustrations from 3D printing (this has since been started in previous posts on passenger cars). 

Some of these models are LC tops. These are the same as ones I've bought and posted about previously, but putting them up against the latest additions to the four-wheeled coal train, the Trackgang whitemetal LCs (the brown completed one below) shows a contrast when it comes to the details like the placement and 'finery' of the ribs and internal tie-down 'bumps', and also the overall straightness and squareness that 3D Printing was supposed to help us with, although I suppose in this case, bent bodies were pretty realistic for coal route LCs!

But also note the chunkiness of the ribs and wall thickness of this particular design (and my earlier KS wagons).

My Z scale exploits have made me pay more attention to wagons 'riding high', and in recent projects you may have noticed me sanding down bogie mounting points and inserting the Peco chassis 'up into the body' for the recent batches of LCs. To my eye, this presents a far more accurate portrayal of the LC than when the top is sitting way up high on top of the chassis.

Modelling that lower look with these printed models (or making any alterations at all) is more of a pain than with scratchbuilt stuff, because the resin is so tough and brittle, so to 'raise the floor' you really have to get in there with a dremel, which is challenging to get into tight corners, and messy.

To make a proper low-rider, I need to remove the above areas painted black with a Sharpie pen, to let me insert the chassis. 

In fact even without my low-rider desire, I'd still need to either thin the Peco's plastic chassis or remove a smaller amount of resin print because those walls are so thick the Peco won't fit between them as intended anyway.

And ideally, for looks, you want to thin the inner side walls a little when viewed from the top. Further surgery had to be performed on the Pecos (see in the pic below) to make up for not being able to get a dremel deep into the corners of the underside....

The end result is nice:

In the pic below, compare the low slung LC (light brown one at right) with the sit-on-top Euro-look LC (darker model at left) in the below pic:

But getting to this point is too much work for a 3D print. I could have scratchbuilt this from styrene in half the time I spent dremelling. Why not just modify the design to save everyone the hassle? 

And that is exactly what Lewis has done with his latest creation, after some back and forth with Dandruff HQ.

This is his build in the pic above, looking pretty sweet. This is a great example of "if you're going to go to the effort of designing it, why not make it as good as you can?"

So, a number were acquired, but they have been sitting on my bench for a while as they required some pondering time. The outsides look superb:

That's some mighty tasty and fine detail. Note the handgrab and footstep on the end (the little knobs on top are from supports used in the 3d printing and curing process and are easily removed with a file.

The floor is supplied as a separate piece:

The challenge is fitting it... The tops have a little protrusion that is probably supposed to locate the floor, but mine were only on three of the inner sides. It was a very tight and tricky fit for the floor. Plus they are inclined to be a little warpy by their flat nature, so after many attempts I decided there was no way I was going to get flat or consistently located floors without assistance. 

After fiddling with various sizes of plasticard rod, I reckon 0.060 inches-worth of Evergreen styrene is the right depth of stopper to have the floor sit at the height I want.  So strips of .040x.060 were cut and levelled with the bottom of the side walls thus:

I quickly found it easiest to do it the way pictured below, holding the wagon down and simultaneously pressing the strip against a knife blade (or a ruler or something) held in the other hand for a few seconds while the superglue took:

Then it was time to create some NZ120 marching powder by thinning one side and one end of the floor:

So the floor drops in nicely against the stoppers. If it warps up in the middle that's no drama, because the chassis will be secured at the corners anyway:

From here it was paint time: various shades of reddy brown on top:

And some drybrushed brown on the bottoms as the wagon assembly plant rolled into action:

Ta-da:

About 15 years ago, I had three holy grails for NZ120. 

1. A module standard.
2. A realistic one-piece modern freight bogie.
3. And a relatively cheap LC and KP top that you could just pop onto a Peco - meaning anyone could churn out trains quickly without needing any special tools or skills.   

It looks we are getting very close to being 2/3rds of the way there.

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.

Mark's Model Works (MMW) bogies and railings for carriages

DB bought a set of 3D printed wooden carriages when he dipped back into NZ120 about 15 months ago: 

This was to be a post on 3D printing, but I've decided to break that into three parts, so more on the carriages soon, but this post is about some roundy feet for them.

Options include nice plastic bogies with superchunky wheels from some olde-timey carriages (Ibertren?) as seen under that 30-foot van; or Kadee passenger car bogies (a little small, but these 1017s don't look terrible after the removal of some superfluous brake and stabilisation detail; plus they have a bonus coupler. 1014s might be better but I've never seen any in the wild); or these scary-looking Mark's Model Works etched bogies. Eek.

I've seen a completed MMW set before and they look lovely, but there's no way I could ever make those up with my fuzzy eyes, wobbly hands and 1940s-era welding axe and matching skills. 

But why not give them a crack... so I studied the instructions with an intensity and frequency that no male has ever employed studying instructions before.

To my surprise, they came together fairly quickly. After about one and a half hours I had the six made up, including bearings, wheels and soldering. About twenty minutes of that was spent cutting the ends off some petrified clothes pegs (as recommended in the instructions) to make clamps that are perfect for holding things together while you apply the solder that locks everything together. The hardest part is arguably the first step, crimping the leaf springs.

The eagle-eyed may note that there are three subtly different models of bogie here (different numbers of leaf springs among other details. 

I bought some Dundas DP09 brass top hat bearings from Trackgang a while back and they coincidentally fitted the MMW bogies perfectly, indeed being recommended in the instructions.  

The wheels are some pricey Bachmann/Farish BR coach bogies from Ironhorse, purchased randomly a few months ago, and their axle length happens to fit perfectly too. They are a nice broad diameter, but are discs, not spoked, if that matters.  And oddly they come in a pack of ten. Just the perfect amount for... two and a half carriages. Shrugs shoulders. The sixth bogie was filled with two Peco plastic wheels, which are a tad short in axle length, but with the frame bent inwards a smidge, they roll ok.

In summary: as long as you follow the well-illustrated instructions, the bogies are not hard to fold up and solder. They are etched in phosphor bronze, which is nice and stiff and springy, but is a forgiving material if you do start folding something the wrong way, as it doesn't fatigue as fast as brass. As also noted in the instructions, I needed to separately put a splash of solder in to affix about half the bearings in place. This requires slightly more finesse than I possess, but my efforts didn't hinder their operation or looks. Even my neanderthalesque soldering skills had the main soldering job (one line across the top of each bogie side) come out quite neat.

Speaking of looks, the bogies really look stunning. With this success, I must have a crack at those MMW brass IA wagons that I've had stashed away for a dozen years. 

Keeping the story on MMW, the carriages were topped off with his etched end railings which are insanely pretty:

These are just gorgeous. I use a Sharpie black marker to tediously colour them in before cutting and folding. This gives a much 'finer' effect than painting them with goop after they have been installed (as if you could get a paintbrush in there to do the inside faces anyway). I decided to not add the steps, as they didn't quite fit the stepwells. I may put them on later. I also inadvertently omitted the curved handrails on the red carriage ends. It seems that one (obviously, in hindsight!) should do this before glueing the end cages in place that prevent future access... 

More on the carriage build in the next one.....