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)

Trailers for CNR D-1

In other passenger-carrying news, Shapeways has delivered my 3D Printed shells for C-1 and C-2 – the two trailers that completed the train set hauled by D-1:

CNR C-1 and C-2

These were designed by my friend Stephen Gardiner. Regular readers will recall that he’s done these for himself in HO – and has kindly re-sized and tweaked the plans for printing in S scale. (You can find all of my posts about this project in the CNR D-1 category.)

Like the power unit, the trailers are a great start but will need a fair bit of finishing to complete. First up, I’ll have to wash the bodies to remove the waxes used in the printing process, glue the roofs in place, then spray everything with an automotive filler/primer so that I can see what work needs to be done. I’ll also need to cut some floors for the two trailers.

Meantime, I’ve ordered NWSL wheels and bearings for the 6′-6″ truck kits I picked up from William Flatt.

I’m also looking to order a Helicoils starter kit for 2-56 machine screws: I borrowed one from a friend to mount the D-1 body to the frame and this is a marvellous system to use in 3D Printed materials when one expects to fasten and unfasten parts regularly. (I’ll write more about Helicoils in a future post.) As the photo below shows, Stephen designed in mounting posts with pilot holes, designed so that I could use Helicoils and 2-56 machine screws:

CNR C-1 and C-2

I continue to gather the parts I need for this project, but once I have what I need I suspect the assembly will go quite quickly.

When the CNR built “Iron Man”

 photo CNR-D1-Shell-Frame-01_zpsymt5ejjz.jpg
(It sure looks like Tony Stark in a suit, doesn’t it? Not a beautiful example of streamlined self-propelled railway equipment…)

The CNR D-1 project is coming together nicely. My friend Stephen Gardiner did a terrific job of resizing his HO scale 3D print files for the body and roof to S scale, and the print I ordered arrived late last month from Shapeways. Last week, I visited my friend Ryan Mendell, who cut the brass frame for me, and we modified the frame to make it fit into the body:

 photo CNR-D1-Shell-Frame-02_zps3gjojtj0.jpg

Thanks, guys!

My next step will be to wash the shell, then apply a coat of primer. I’m finding that the translucent material in which it’s printed is almost impossible to see properly, because of how light passes through it and reflects about. I certainly can’t do any work on detailing the shell until I can see the thing. A coat of primer will – I hope – smooth the already mostly-smooth finish on the print. If not, it will show me where I have to sand.

Based on the success of this print, Stephen has released – and I have ordered – the S scale prints for D-1’s two trailers. Those should arrive by the end of the month. Stay tuned…

D-1 details from William Flatt

While I’ve been waiting for Shapeways to deliver my S scale CNR D-1 body, I’ve been collecting bits and pieces to detail it and the two trailers (C-1 and C-2) that it will eventually haul.

I’d been looking for suitable unpowered trucks without much success: D-1’s trailing truck had a 7′-0″ wheelbase, while the wheelbases for the trucks under the trailers were 6′-6″. Everything I found that looked right was too big – 8′-6″ to 9′.

Then it occurred to me that I was dealing with wheelbases more commonly found under interurbans, not mainline passenger cars. What I needed was parts for S scale traction modelling – the kind of stuff done by William Flatt:

 photo NST 80 Merritton_zpsbkg2loam.jpg
(Click on the image to read more about William’s layout)

Fortunately, William is also a manufacturer. So I checked out his catalogue of S scale traction parts, and found exactly what I needed:

 photo D1-WF-Truck-01_zps5hz0w3gr.jpg

This is a 6′-6″ side frame – bang on the for the trailers and close enough (in S, anyway) for the rear of D-1. I ordered enough for the train set, plus truck bolsters. I still need to clean up the castings so I’ve only temporarily assembled a truck with a drop of CA on each end of the bolster, to get an idea of how it goes together. The wheels are 36″ NWSL finescale. I must decide whether I’m adding bearings inside the white metal. While my gut instinct is that I should, I also know live steam enthusiasts who do not and have not had problems with much heavier equipment. The axles turn at fairly slow speed, after all. But I’ll talk to my machining experts about that…

While ordering the trucks, I ordered some other parts from William, too:

 photo D1-WF-Details_zpsbqsf4cmh.jpg

(William’s service was exceptional, in case you’re wondering. S scale lives and dies by small suppliers and it’s good to have guys like Williams helping the rest of us build models and layouts.)

My haul includes seats for the trailers, plus underbody and roof details. It’s not everything I’ll need to finish the project – and there’s probably a bunch of stuff in the pile that I will not need. But it’s a start, and while I install these parts I can figure out what else I need, and where to find it.

Meantime, I can build trucks and determine how I’m going to mount the trailing truck at the rear of D-1. My friend Ryan Mendell, who cut the frame for me, left a large opening on purpose because we did not know what type of truck would be used here, and we wanted room for pick-up wires.

 photo D1-WF-Truck-02_zpscrjmczhx.jpg

The D-1 body should arrive next week.

D-1 body ordered

My friend Stephen Gardiner and I attended the 2016 Toronto RPM over the weekend, and he brought along his HO scale model of CNR D-1, C-1 and C-2 to display. The model is a real eye-catcher:

 photo CNR-D1-Resize_zpsorelcdl5.jpg

The prototype train set never received a fancy name like “The Flying Yankee” so it’s a real alphabet soup to describe. But it was the CNR’s failed attempt to modernize its aging fleet of diesel-electric motor cars. The D-1 was a bust and rather than pursue this project, the timing was right for the railway to instead invest heavily into Budd RDCs.

But no matter – it’s a unique piece of equipment and a real conversation piece, as I hope the photo suggests.

To build his model, Stephen drew up the D-1 and its trailers and had it 3D Printed at Shapeways. As regular readers will recall, he’s working on converting his design into 1:64 so I can print a copy to run on the S Scale Workshop exhibition layout. Reworking the model for S required more than simply scaling up the HO plans: The larger scale required the body to be split in two in order to fit within the Shapeways print envelope, and there were other changes to be made. But Stephen informed me on the weekend that the S Scale version is ready, and yesterday I placed my order with Shapeways for the body and the roof:

 photo D1-Sscale-Shapeways_zpsoqcgkdd0.jpg

I already have a frame, courtesy of my friend Ryan Mendell:

 photo CNR-D1-Frame-01_zpsyuh0peon.jpg
(Click on the image to read about the frame)

Meantime, I’ve ordered a trailing truck for D-1 (plus trucks for the two trailers) from American Models. While I wait for the D-1 body to arrive, I’ll work up a list of detail parts to acquire from companies such as BTS. And then of course there are the two trailers. I can detail D-1 while Stephen converts his 1:87 trailers to S scale.

(And on a technical note, I’ve now added a category link to the blog for this project: CNR D-1 will filter all the postings related to it.)

Thanks for your work on this Stephen – it’s going to be an awesome addition to the Workshop layout!

 photo D1-C1-C2_zpsd7c5b538.jpg

A frame for D-1

 photo D1-C1-C2_zpsd7c5b538.jpg

Thanks to my friends Stephen Gardiner and Ryan Mendell, I now have the beginnings of an S scale model of CNR D-1 and its trailers.

As I wrote last summer, Stephen has been drafting the artwork to 3D Print an HO scale model of this one of a kind train set, and I’ve encouraged him to re-scale and tweak the artwork for a model in 1:64.

 photo StephenG-D1-Shell_zpsi018zspf.jpg
(Click on the image to read last summer’s post about this model. Note that the 3D Print rendering is of D-1 at a later phase in its life than the photo at the top of this post. Most noticeably, the cooling vents above the cab are taller.)

One stumbling point for us was how to power an S scale model. Stephen’s HO version is based around the frame and mechanism from the Bachmann (Spectrum) doodlebug. But there’s no mass-market equivalent for an S scale project.

The good news is, the D-1 is powered only by the front truck – and that truck has the same wheelbase as an EMD switcher. The side frame even looks like something you’d find under an SW. So, I asked around and purchased an S Helper Service SW-1 from my friend David Clubine at Ridgehill Scale Models. That donor engine provided a power truck and a motor. Now, what to mount them in?

That’s where my friend Ryan joined the project. Ryan, like Stephen, is handy with CAD programs. He also has access to some pretty incredible machinery. So he and Stephen put their heads together and last night, Ryan presented me with a frame:

 photo CNR-D1-Frame-01_zpsyuh0peon.jpg

As should be obvious, the frame is crafted from a solid piece of brass. Ryan drew the frame then cut it out using a water jet cutter – a machine that blasts a fine stream of water at Mach 3 (!) and makes short work of work like this. The frame took about five minutes on the machine.

Ryan added pillars to support the motor, then cut specific parts from the SW-1’s cast metal frame to complete the D-1 mechanism. These include the motor mounts and the truck mount. Machine screws hold everything together. A NWSL universal kit will provide a new drive shaft linking motor to truck.

A line of small holes along the frame will provide mounting points for the body. Stephen will be able to add blocks of material to the shell before printing it, and we can then drill these blocks for more machine screws.

The large square hole at the back of the frame gives us some flexibility to mount the unpowered truck: We’ll figure out the specifics of that mount once we have the truck in hand. (If I recall, Stephen has drawn up side frames for the rear truck, plus the trucks under the two trailers that this self-propelled baggage motor hauled. A simple truck bolster should do the trick. ) In the meantime, I propped the rear of the frame on the SW-1’s fuel tank to take the above photo.

I’ll have to scratch-build tanks, equipment boxes and other details for belowdecks, but since this streamlined train set was converted from one of the CNR’s conventional doodlebugs, I’ll base the details on those found under my CNR gas-electric, and I’ll be more than happy with the result.

Stephen is still working tweaking the D-1 body (and has not yet re-scaled the trailers, C-1 and C-2), but there’s no rush. This never ran to Port Rowan – it’s a project for use on the S Scale Workshop modular layout – and I have plenty to do while I’m waiting for the body shells. But I feel that an important hurdle has been cleared, so that this project can go ahead.

Thanks, Stephen and Ryan, for your work on this. I really appreciate it, and I know that those visiting the S Scale Workshop layout at future exhibitions will too!

Ops, talks, D-1 – and 2-for-1 fish and chips

My friend Stephen Gardiner visited last night – and we had a great time divided between an operating session, discussions ranging from tree-making to 3D printing, and dinner.

Stephen volunteers at the Toronto Railway Historical Association and one of the things he’s working on is a diorama of the Don Station and surrounding buildings that are located in Roundhouse Park:

 photo RoundhousePk-DonStn_zpsp2z8ohiw.jpg

As part of this project, he needs to build some trees – and he wants to do a good job on them so he wanted a first-hand look at how I do mine. I was happy to oblige, and gave Stephen a quick overview of the steps required. (Stephen – sometime when I’m planning to build a bunch for Port Rowan, you can come over and we’ll work on them together.)

It was Stephen’s first visit so of course we set aside some time for an operating session.

Stephen took the engineer’s seat and quickly mastered the workings of TouchCab.

We ran a short freight extra behind 10-wheeler 1532, and the layout ran flawlessly. (No derailments: huzzah!) I like when that happens. Faultless running makes for a good time, and more than an hour breezed by as we lifted one in St. Williams, and set off two and lifted one in Port Rowan.

We also talked about another interesting project in Stephen’s hopper: a 3D printed model of one of the Canadian National Railway’s flirtations with streamlined passenger train sets:

 photo StephenG-D1-Shell_zpsi018zspf.jpg
(A work in progress. Click on the image to see the not-yet-for-sale file on Shapeways)

Stephen’s working in HO, but I’m trying to convince him to rescale to S as well because – darn it – I want one to run on the S Scale Workshop Free-mo layout. Or, at least, to “pull”: The D-1 was rebuilt from an oil electric and, with two matching trailers, was a distinctive but ultimately unsuccessful experiment. In fact, if one were to model it one might consider not powering the model: it logged many, many, many miles being hauled behind a steam locomotive after breaking down.

D-1 went though a couple of changes over the years, including adding a taller cooling bulge above the cab. Stephen is drafting the latter configuration, and he’s been looking for photographs that show the exhaust ports built into the top of this bulge for the unit’s Caterpillar D-397 12-cylinder diesel.

(If you have photos that show the roof of D-1, Stephen would love to hear from you. Contact me and I’ll forward your information to him.)

We ended the evening at The Caledonian, a terrific Scottish pub about a 15 minute walk from my place. Monday nights are two-for-one fish and chips, don’t you know! Delicious with a cold pint of BrewDog 5 AM Red Ale on tap.

Great seeing you, Stephen! Good luck with the trees, I hope we can find some exhaust pictures for D-1, and let’s run some trains again soon!