Friday, September 19, 2014

An exploration into 3D printing | 6 Comments - Click Here :

    Keith Hayes - A challenge modeling in 1:64 is the lack of large period masonry buildings. One either has to kit-bash, scratch build or look to other scales. I am modeling a spur to the Arkansas Valley Smelter and needed a more substantial masonry building for the spur. A visit to the local hobby shop resulted in purchase of a Walthers 1:87 Dayton Machine Company kit. The brick detail is nice and the size was right, but the windows were a dead giveaway. I would clearly need to adjust these to make the kit look right on my 1:64 layout.

    An emerging technology you have probably heard of is 3D printing or Rapid Prototyping. There are now several vendors that allow you to post your models to their servers and they will print the part for you and mail it to you. The vendor I used is Shapeways ( A number of modelers have created models and parts and a variety of scales, so be sure to check out the website thoroughly, as what you want may already be available.

    3D printing uses different resins in a string, kind of like a dot matrix printer, except the printing head moves in all three dimensions and thus can lay down resin not only in the X-Y plane of the 'paper,' but also in space along the Z axis. Because the printer builds one layer at a time, it is possible to build very complex forms that would otherwise be very difficult to model.

    Shapeways will support a number of different software products. I chose to model my parts in SketchUp, which is free, and export the files as a .DAE format. This is all explained on the Shapeways website. Shapeways offers a number of resins, and it is important to read the limitations of each, as each has different resolution requirements. This was among my chief issues. Also, the build area on current machines is less than a cubic foot, more like 8" or 10" on a side, though building something this large would be very expensive.

    For starters, the resolution issues are in metric: for the resins I selected, I was generally limited to sections no smaller than 1 mm and relief of at least 0.5 mm. These are large in 1:64, over an inch at scale. As this was an experiment, I ordered parts in a couple different materials, flexible plastic, frosted plastic, and frosted detail plastic. Each of these comes in at different price points.

    I chose to build my windows to scale. Were I to do it again, I would probably build them full size, scale them down and check the resolution issues. When you submit a model to Shapeways, it first goes through an automated check and then before production a real person checks the file for issues. If your file has challenges, you will receive an e-mail illustrating the issues that need correction.

    I started with the windows as I needed the most of these. I am modeling an industrial building and chose to use a steel sash window with an operable part in the middle. The neat thing about this technology is that you can customize to your hearts content and only order what you need. I tried the flexible plastic, which is the lowest price point and reasonably affordable (~$1 per part). This material is grainy and has the potential to warp. It also seems difficult to sand. I modeled these vertically (as if they are in a wall plane) and they have a noticeable front and back side. They take paint fine.

    For the next project, I modeled some doors. At a friends suggestion, I modeled these flat (in the ground plane) to address the grain issue. If anything it may have made it worse. The doors are all in plastic or detail plastic, which triples the cost. This material smells a bit like coconut and seems to sand better. It takes paint okay, but paint can settle in corners easily.

    I now have all the parts I need for my kit-bash. Shapeways has changed their website quite a bit in the six months I have been using it. It takes 2-3 weeks to get parts once you post them, though you can pay more for speedy mail service. The ability to customize is a real plus; the challenge is the coarseness of the resolution in small scales and the grain of the material. This can also be expensive: with shipping I have about $100 into my window and door experiment.

I was excited to use 3D printing to model a cattle guard built of surplus rail, but the resolution limitations rejected the model. I am going to give the technology one more chance with a model of the Leadville water standpipe. Otherwise, I think I may turn to laser cut wood for the Leadville depot and roundhouse windows and doors.

The original Walthers kit.

All the parts I have ordered. Using SketchUp, I was able to create a family appearance by using similar window sizes. You can see the door on the lower right, I was able to create a recess for glazing: one can get pretty fancy within reason.

The doors are frosted detail plastic and have a very noticeable noticeable grain, especially in the recessed panels. These parts have been primed. I probably could have added door hardware and a reveal indicating the joint between the doors.
Unpainted window that has been sanded.

Image of two painted doors. The left one looks pretty good, though the rattle can gloss filled in some of Technology grain and details, it captures the look I am after  The rear of the door on the right shows the grain: it could be different on two otherwise identical parts.

 Starting to look real. Ignore the painters tape.

Keith Hayes
Modeling Leadville in Sn3
6 Comments - Click Here :
  1. Very interesting, good food for thought.... What about 3D scanning or is that too far in the future?

  2. Looking forward to seeing the finished product!

  3. Keith has added three more pictures to this post. I too am looking forward to his final result.

  4. Trev, 3D scanning is here--we have investigated it for some building projects. It is rather expensive, but for certain applications is just the ticket. For example, NPS has been doing some scans at Mesa Verde, and it is remarkable (to me) how different the scans are from previously (presumably carefully executed) measured drawings. I think the application we are all waiting for is a way to execute figures in particular poses affordably.

    In other news, I see that Dremel announced a 3D printer last week. The post I saw did not give high marks for the resolution and the reviewer indicated a continued preference for Shapeways. If folks have tips on how to improve the resolution, I am all ears. I continue to work on my Leadville Water Column.

    Keith Hayes
    Leadville in Sn3

  5. Nice work Keith. Been using Shapeways for several years now for both Sn3 and On3 (San Juan Decals D&RGW 6200 flat car kit parts), though I did design some clerestory coach roofs for Heartland Railway in HOn3 which came out nice, even using one of the cheaper materials. There are other rapid prototypers out there which I'd like to try, but the Shapeways business model suits my needs for now.

    I would rather stick to the larger scales for the resolution issues you mention, I've even done some 1:20.3 which can get pricey. I use the Frosted Ultra Detail (FUD) for the majority of my pieces, again for the finer detail.

    Keep us posted on your efforts.

    Mike McKenzie
    Frankfort IL

  6. Mike:

    Thanks for your comments. It is reassuring to know that others struggle with the texture and resolution issues I have experienced. Darel has a link to an N Scale Blog, 'Prince Street Terminal,' and that modeler appears to be using Shapeways to model many items for his N Scale pike. While the posted renders look excellent, they are just that--renderings, not the actual casting or 3D print. Jack Burgess also wrote a fine discussion on this topic in the recent issue of the Gazette--quite by coincidence I should add. Jack is a very discerning modeler, and I was surprised he did not note the texture issue, though you can see some grain in at least one of the photos.

    If you have an example of your 3D printing, please contact Darel, and I am certain he would be happy to share it. In the mean time, I continue to work on the Smelter.

    Keith Hayes
    Leadville in Sn3