When the CNR built “Iron Man”

CNR D1 Shell on Frame
(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:

CNR D1 Shell on Frame - V2

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…

12 thoughts on “When the CNR built “Iron Man”

  1. Hi Trevor,

    I recommend you use auto filler primer, it helps filling the little ridges from the printer.

    • Salut, Simon:
      Thanks – great idea.
      A test with my finger tells me the ridges are not that severe – certainly better than what I’ve seen previously from 3D printers. I’m hoping that an auto-filler primer will make them go away. If not, I’m prepared to fill and sand as needed.

  2. From my experience, some areas the filler primer will do it and some others you might still have to do some light sanding. Hopefully, not in areas where there are rivets or other surface details.

    I had this suggestion from Willy Monagham, who printed several cars so far using FUD from Shapeways. He also suggested to soak the parts in kerosen to remove any leftover wax/support material used during the printing process.


    • Great ideas, Simon. Cheers.
      Stephen wisely designed the 3D Printed body without rivets. I can sand to my heart’s content. I then plan to add Archer rivets and other details.

      • I don’t know that i can legitimately claim to be intelligent by not including rivets. If the modelling software i used worked better, i would include some rivets, but it has serious issues exporting anything that looks like a rivet to the 3d print file. Something in the way it is scaling the rivets down from 1:1 t0 1: whatever seems to break them, but it does mean you aren’t sanding off rivets to get a smooth surface from the 3D print.

  3. Hello Stephen,

    What do you use for program? I use Sketchup Pro and it has problems with small dimension (anything below 1/64″). So I work full scale and scale down just before exporting to STL.

    Additionally, I found that the STL from Sketchup have many errors that Shaopways seems to correct but sometime, I noticed not all small details were showing. So I decided to run my STL files though an STL corrector (on-line) and in addition to reduce drastically the file size, the model seems to be well rendered in Shapeways.

    The free on-line service is : https://modelrepair.azurewebsites.net/index.php

    You need to create a MS account if you don’t have one already.


  4. I’ve used MR Surfacer 1000 in the past but it usually takes a couple of passes to build up. Jack Burgess recommends auto spot filler and primer. I’ve tried this recently and I think it would work with your model. I think you were wise to leave the rivet detail off.

    My one test with FXD was pretty much line free but you really pay for it (50% more than FUD)

  5. Did the body arrive in one piece?

    How is the resolution? Will you need to supplement small details with Archer rivets and welds?

    • Hi Keith:
      Yes, the body arrived in one piece (actually, two: But it was designed as a two-piece body because it was too long to fit in the Shapeways printing envelope). As was fine.
      The resolution is quite good. I will have to prime it with an automotive primer – something that does a bit of filling. I’ll do this for two reasons:
      1 – to smooth the finish. It’s a bit “sandy”, but not very much.
      2 – so I can actually “see” the body! Looking at semi-transparent material is really hard. Once I have the primer on, I’ll be able to see how well the body printed, and then I can decide what sanding, if any, I will have to do.
      Stephen did not add rivets. This will make it easier to sand if necessary. I will then apply Archer Rivets following prototype photos.

  6. Hi Trevor,

    Before painting or detailing, it is highly recommended to soak and clean the FUD/FXD parts with bestine . I soak my models for 24 hours to remove all of the wax support residue, and have never needed to do any scrubbing. The bestine will dissolve the wax and not harm the FUD material. Once cleaned, the model will turn opaque, and it becomes much easier to see what you are doing. If you fail to fully remove the wax material, your paint may eventually peel from the model.

    Kind regards,

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