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 (www.shapeways.com). 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