CNR 3640 in RMC

RS18-Potrait

I’ve written a feature for Railroad Model Craftsman magazine about my model of CNR RS-18 3640 (shown above). This is an Overland brass import from many years ago, which I tuned so it would run better. I then made some basic cosmetic changes and added DCC, sound (with two speakers) and lights. I then painted the model – including creating my own masks for colour separation.

You can read about the model in the October, 2019 issue of RMC. Click on the cover to visit the RMC website:

RMC Oct 2019 cover

CNR D-1: Bring out the big guns

CNR D-1 and the air eraser
(Progress on the shells: Knocking down the ridges on one of the trailers)

As mentioned yesterday, I’ve decided to make some progress on the long-stalled CNR D-1 project.

CNR D1 - Grit blasting at Ryan's

A big stumbling block was how to deal with the ridges that are a characteristic of 3D Printed items. Such items are built up in layers and there’s often a ridge where the layers are bonded together. This stratification was very much an issue on the 3D Printed shell for D-1 and its two trailers.

Sanding and surface primer is the usual approach to addressing this problem, but there’s a lot of shell to cover here, and the sheer magnitude of the project made it easy for me to say, “Hmm… I wonder what’s on TV?” I needed a better answer. And that answer came in the form of a big red box fitted with cocktail-length rubber gloves…

Ryan and the air eraser
Ryan sets me up for a day of grit blasting

I visited my friend Ryan Mendell yesterday for an afternoon of hobby fun. (Stephen Gardiner, who designed the D-1, joined us too.) Ryan has been building patterns for resin casting and recently started his own hobby business, National Scale Car. He makes many of his masters using 3D Printing and was looking for a better way to deal with the ridges – and found the answer in the form of a grit blaster. I was curious about how effective it was, so I arranged a visit.

I worked on the three bodies for a couple of hours and I’m really happy with the results. The grit blaster (also known as an air eraser or media blaster) did a terrific job – especially in areas where it would be difficult to sand by hand, such as the recessed doors. In fact, I realized that if I focussed on those difficult areas, I could do the large flat sections of the shells with sanding sticks – or, even better, Ryan’s Tight Spot Sanders.

Ryan has a Paasche Air Eraser and a Blast Cabinet by Central Pneumatic (obtained from Harbor Freight). For the D1, I was shooting 220 aluminum oxide at 80 psi.

The before and after photos below show a definite improvement in the curved nose of the power unit:

CNR D-1 Texture - Before

CNR D-1 Texture After

The translucent nature of the 3D Print medium used makes it difficult to see the improvement, but running a thumbnail over the surface tells me the ridges are much less pronounced. I will finish sanding this shell using my Tight Spot Sanders then give it another application of Surface Primer and see how it looks. I expect this will be a “repeat as necessary until satisfied” operation, but I now have a strategy for tackling the project, which is the important thing.

Would I add a grit blaster to my workshop? Well, I do like tools, so the answer is “probably”. I don’t have the space right now – there are other things in the shop that must find their way to the curb – but I do have a suitable air compressor to power a blaster, and I’ve already thought of where I would hang the booth once I clear space for it. I would want to do something about muffling the noise of the air compressor, but a sound-insulated cabinet could take care of that.

Meantime, I envision another trip or two to Ryan’s before this project is finished. Thanks for the help, Ryan – the next beer is on me!

A drive train for D-1

CNR D-1 Drive Train

I’ve decided to tackle a few projects that have been stalled, to see if I can make some progress on them. The CNR D-1 passenger train set is an example – I last posted about this almost three years ago, and it’s been collecting dust since then. There are some issues to resolve, and other projects called…

Yesterday, I decided to solve one of those issues: The drive train. I was most of the way there: The motor and power truck – both donated from an S Helper Service SW1 – were installed. But I needed a drive shaft to connect them. I dug through my stash of Northwest Short Line driveline components and found a mostly suitable shaft, plus universal couplings.

I say “mostly suitable” because I had no drive shaft material that would fit the universal coupling at the gear tower end of the drive. Everything was too small.

Fortunately, I have a lathe and making a bushing is an ideal project for it. I had some brass tube that fits the universal coupling, so all I had to do was bore it to accept the drive shaft. I chucked the tube into the lathe and got to work…

Boring the bushing:
Boring the bushing.

Test-fitting the drive shaft:
Test fitting the shaft

Parting the bushing:
Parting the bushing

I cut a length of 2.0mm drive shaft, added the bushing and universal coupling at the gear tower end, added a universal ball at the motor end, and assembled the drive. Everything press-fits nicely – I experienced no slipping. (If I do in the future, I will add some Lock-Tite.)

The assembled drive

I tested the drive with a 9v battery, running it in both directions while wiggling the truck about and turning it to its extremes, and all runs smoothly and quietly. I was worried about the extreme angle of the drive shaft – but that turned out to be a non-issue. Progress has indeed been achieved!

The next step is tackling the texture of the 3D Printed body shells. I’m visiting a friend later today – we believe we have a solution for this. Stay tuned…

CNR D1 Texture (Before)

CNR 3737 :: Snow melter fittings

CNR 3737 - Prototype Photo

I’ve been thinking about the snow melter equipment on my CNR 2-8-2 project ever since I installed the big wrapped pipe for it last week. I know that this pipe supplied steam to equipment that melted the snow and ice out of switches in yards. But beyond that, the photo of 3737 that inspired this build (shown above) doesn’t really make the fittings clear to me.

So, I did some research with the aid of Canadian National Steam! – the the excellent series of books by Donald R. McQueen, published a few years ago. In one of these, I found a photo of CNR 2-10-2 4033 with a much clearer photo of the snow melting equipment – a portion of which is shown here:

CNR 4033 snow melter detail

I’ve highlighted three important points with white arrows. First, there’s are two shut off valves on this pipe – one near each end of the pipe. Second, the front end of the pipe appears to be fitted with the same sort of steam line connection that’s used on passenger cars for steam heating.

With this information, I look another look at my subject photo and things became more clear:

CNR 3737 snow melter (detail)

First, now that I know what to look for, it’s easy to spot the wheel on the shut off valve just ahead of the steam dome. And while I cannot see the second shut off valve, at the front end of the pipe, I will assume it’s there and model one accordingly. Perhaps it’s hiding behind the handrail in this photo.

Finally, while I had spotted the steam line connection back at the start of the project, I didn’t know if there was anything more to the system at this end of the pipe: now, I know that this is all I have to model.

Precision Scale offers valves in a number of pipe diameters, including ones cored for these wrapped pipes. So I’ll be placing an order for those soon. And BTS makes the passenger car steam line connectors, which will work fine for this application. I’m already building the shopping lists…

CNR 3737 :: ash pans and doors

Yesterday’s work session with my friend Andy Malette focused on the firebox of my CNR 2-8-2 project – specifically, the ash pans.

CNR 3737 ash pans and doors

The stock model has a pair of cast brass plates that run across the bottom of the firebox. These are screwed to the body of the model from underneath, as they must be removed in order for the motor slide into the firebox area. The plates project beyond the edge of the firebox but needed to be bulked up to better represent the bottom of the prototype. So I soldered some bar stock in place along the top of each plate, while they were still attached to the model – being careful to not solder them to the firebox wall. I then unscrewed the plate and shaped the bar on a bench grinder – working a little bit at a time and cooling the brass in a pot of water so that the solder would not melt and the parts separate.

Andy had prepared for the session by cutting some square tubing to create the frames for the four ash pan doors – two per side. I filed these to better fit against the curve of the base plates, soldered them in place, then returned to the grinder to finish them. A light touch was required, with regular checking to make sure I was grinding them so that their outside edge would be vertical when installed on the model. I finished these with a file.

Finally, when I was satisfied with the door frames, I made the doors themselves. These are simply pieces of styrene sheet cut to fit between the sides of the door frames, left long and soldered in place, then trimmed level with the top of the ash pan.

With these built, I test-fit the new ash pans in place. I had to gently bend some piping out of the way to get them to fit, but otherwise it went fine.

The last step was to add two blow-downs to the firebox, on the engineer’s side. These are spare castings from Andy’s CNR K3 Pacific project from a few years ago. I cut off a large discharge pipe on each. Then I drilled holes in the firebox side, soldered the castings in place, and added smaller discharge pipes that line up with the bottom of the ash pans. There’s a large hole from a removed casting that I’ll need to fill – the easiest way will be to simply solder a brass NBW casting or a piece of brass plate over it and be done with it.

There’s lots more to do, of course. But I have a busy couple of weeks ahead of me so we may not get back to the project until next month. Meantime, I’m putting together a list of details that I need to buy to continue this build.

CNR 3737 :: The big pipe, and other progress

CNR 3737 - Prototype Photo

I had some time today, so I put the phone on mute, turned off the computer, and spent the day in my basement workshop. The result is, I made a lot of progress on my CNR 2-8-2 project.

The first order of business was piping…

The big insulated (wrapped) pipe across the top of the locomotive in the prototype photo is the primary reason I picked CNR 3737 to model. This unusual feature was to deliver steam to an appliance at the front of the locomotive that was used to melt snow and ice out of yard switches in the winter. The melters themselves are not visible in the prototype photo – presumably, they were removed in the summer, and this picture was shot in August. But the steam delivery pipe is very obvious.

Months ago, my friend Andy Malette provided me with a length of wrapped pipe from his stash. I straightened it and re-bent it with pliers to approximate the path of the prototype pipe:

CNR 3737 - Snow Melter pipe

I drilled a hole in the steam dome to accept the end of the pipe, then realized that if I soldered it in place, I would never be able to remove the smokebox front. Given that there are lights to install and maintain, this seemed like a bad idea. So, I made sure the pipe was long enough to fit firmly in the steam dome hole, then soldered the pipe to the smokebox front. It now comes off with that front piece, all as a unit. As I add additional details, I will see if this will continue to work. If not, I’ll have to come up with something else.

Now, I have to do more research on the snow melters themselves. Time to go through my CNR steam books, looking at photos…

CNR 3737 - condenser pipes

While piping, I also installed the condenser coil under the running board. This runs from the air pump, behind the feed water heater pump, to the small tank under the running board. It then runs from that tank to the larger tank that’s between the front ladders, on the pilot deck. I bent up the pipe using some 0.032″ wire and mounted it to photo-etched brackets supplied by Andy – although a simple L-shaped piece of brass bar would serve if the brackets were not available.

As a bonus, the pipe to the large air tank is soldered to the short running board next to the smokebox, which helps strengthen this. It has frequently come unsoldered as I work on the locomotive – but it’s not moving now. (I’ll have to come up with a similar pipe to support the running board on the other side.)

Further back, I realized I could add the cover to the steam turret housing, just ahead of the cab. I cut some thin brass sheet to size, rolled one end around a piece of brass rod, and installed it:

CNR 3737 boxtop

Finally, I tackled a fiddly project: the seven triangles that support the cab roof smoke deflector. I cut triangles oversize, tinned them, and soldered them in place. I then ground the backs of them down to size.

CNR 3737 - 7 triangles

This was a messy process, but it worked – although even now I see triangles that need some adjustment. That’s easy enough to do with metal.

While this represents a lot of progress, the biggest step forward is something that can’t be seen in the photos: Namely, that I did this work on my own, without Andy’s guidance. The point of this project, for me, has been to learn how to do this work – and I realize I’m starting to gain the confidence to forge ahead on my own. That’s very good news, because it means I’m internalizing the skill set. I’m certainly no master – and there will be many more sessions with Andy, including one scheduled for tomorrow afternoon – but it feels great that the work is paying off…

Maybe we’ll even get our CNR S-3-a Mikados finished this year? Tonight, it feels like anything’s possible!

CNR 3737 :: details, details

I visited my friend Andy Malette yesterday, for another work session on our CNR 2-8-2 project. This time, we tackled a couple of details.

Up front, I added the CNR’s triangular number board to the smokebox front. This really completes the face of any CNR steam locomotive. I do like the appearance of CNR engines – very stylish, yet purposeful:

CNR 3737 - front number board

At the back, we realized we had not yet installed the smoke lifter on the cab roof. This seemed like a good time to add that part. We cut a piece out of thin brass, curled it in our fingers, then soldered it in place. It was easier than I expected:

CNR 3737 - cab smoke lifter

I like to think of it as the rear lip spoiler – keeping the rear of the locomotive planted on the track at speeds above 50 mph…

The smoke lifter needs seven small triangles added behind it as braces. I’ll tackle that next.

CNR 3737 :: that’s MUCH better…

Last week, I wrote about a wonky headlight on my CNR 2-8-2.

This week, I stole a bit of time from other commitments to hit the workbench. I unsoldered the assembly, repositioned it, and secured it back in place. I even managed to add the mount for the number plate, complete with grab iron. The face of CNR 3737 now looks like this:

CNR 3737 - Headlight fixed

I’m back on track. And it occurs to me that I will have to ask Andy Malette about number plates for our project.

CNR 3737 :: That’s just SO wrong…

Yesterday being Friday, it was time for another work session on the CNR 2-8-2 project with Andy Malette. Andy had prepared a bunch of parts for me to install on the smokebox front, and he warned it would be a challenging day. Boy, was he right.

Mounting a pair of class lamps was straightforward enough – the stock model featured class lamps in the same position as the CNR lamps, so it was a simple process to enlarge the holes to accept the castings, line them up, and solder them in place. I also rebuilt the hinges, which had lost some of their material while turning off the dogs during our previous work session.

The headlight was another story – and all I can say is, it’s a good thing brass is so forgiving because I’ll be removing it all and trying again. Do not judge me for this picture, which I’m sharing to remind myself that this isn’t an easy thing I’m attempting, and there will be set-backs:

The Headlight: SO wrong
That headlight is just SO wrong…

The headlight is a complex assembly. There’s the headlight itself, plus the platform upon which it sits. There’s an angled brace between the bottom of the platform and the face of the smokebox. And there’s a vertical plate (not shown) at the end of the platform, to which the number board is attached. This vertical piece also has a grab iron.

At one point, I had most of these pieces in place – just the grab iron to adjust. And that’s when the smokebox face popped out of the vise and hit the floor. Back to square one, with some swearing and scrounging for parts under the workbench. The second attempt ended miserably, too. And the third attempt – almost four hours into the session – ended up wonky despite my best efforts. I’m going to have to pull the #&$%#& thing off the smokebox face, clean up everything, and try again. But not today.

I’ll get it, eventually – and the sense of accomplishment will be even greater for all the effort that went into it. Then I’ll tackle the number boards…

CNR 3737 :: Smokebox front

On Friday, Andy Malette hosted me for another work session on the CNR 2-8-2 project – and we tackled a major modification: the smokebox front.

New smokebox front

Our donor engines are USRA-designed light Mikados from Overland Models, which feature a smokebox front held in place with 20 dogs. Depending on the class of locomotive (and possibly the builder) Canadian National Railway steam engines featured either 10 or 12 dogs on the smokebox front.

We tend to notice these things, so it was obvious that the old dogs would have to come off and be replaced with new ones in the proper pattern. In this case, I would need 12 dogs – which means I couldn’t even cheat and simply grind away every other dog on the USRA smokebox front.

The Overland Models smokebox front is removable, but the dogs are cast as part of the face. So the easiest way to remove them was to turn them off on a lathe. I worked with very light passes, checking my progress frequently until I was happy with the results. After using the cutter, I finished up with progressively finer grits of sanding paper until all evidence of the dogs had disappeared. (This process also removed a portion of the hinges, but they will be relatively easy to replace with brass strip.)

Once the old dogs were gone, it was time to install new ones. Andy has some dogs cast by another friend of ours, but I would have to drill the smokebox face to accept them, then solder them in place. We moved the smokebox front from the lathe to the mill and added a 12-position indexer to evenly space the holes:

Index and centre drill

I started with a centre drill, then carefully drilled for the dogs, adding cutting oil for each hole. The last thing I wanted was a broken drill – Andy said he’s ruined a couple of smokebox fronts that way – and I’m pleased to report I drilled 12 perfect holes with no incidents.

Andy then locked the smokebox front in the vise and demonstrated how to solder these tiny dogs into place. He did the first one – I did the next 11. A minimal amount of flux, heating near – but not on – the dog, and a light touch with a thin length of solder on the side away from the heat was the key: Done right, the solder would melt onto the face of the smokebox than draw itself under the dog.

Here’s a composite photo showing the smokebox front, before and after the alterations:

Smokebox before and after

I think it was definitely worth the effort.

As part of this work session, I also added a drain pipe to the feed water heater, which I’d somehow missed during last week’s piping session. It’s the smaller pipe in this next photo, just ahead of the large exhaust pipe:

CNR 3737 Piping progress. Engineer's side front.

There are still a few details to address – including the various appliances that mount on the smokebox front. But I now feel confident that CNR 3737 is heading towards the paint shop this year. I’m really pleased with the progress made so far this month and look forward to the next session…