Well, it's been a while since I posted. Not many comments so I stopped writing. My current project is to use additive manufacturing to build an Nn3 scale WP&Y 300 series flat car and companion 25' containers. The container and flat car both have several variants. I began the flat car with a basic 300 series that was a later model that was only used for 25' containers.
I did a first trial run with the basic shape to get the coupler pocket and bolster height correct for Nn3 standards using Micro-Trains couplers and trucks (I use metal Fox Valley wheels). That trial is shown in the photo below. I use a Form 3 SLA printer, so I am still working out the best support system for the print, but this trial print convinced me that I could get the tremendous detail the Form 3 provides and still have a viable print. (You should be able to click on most images and zoom in for more detail.)
After a couple of test runs, I have been able to produce a fantastic level of detail on the grating and the cones that mate with the container sockets. A sample grating run is shown below (brake staff end), along with a print of the cones only (photo is bad, cones look pretty good but the underside is cupped, and then a print of a flat car with the grate and cones as part of the print.
After taking the supports off of the prints, I was really pleased with the results. The next photo shows the underside (showing brake gear detail) and topside of the final flat car print. Assuming that I can adjust my support so it isn't touching the cones, I will print everything at once. If I have to print the cones separately, that is no problem, I have done that and they can be inserted into the main flat car body just fine. A detail photo of the grating and cones is shown in the bottom photo. The detail is outstanding with the Form 3, the grating is 0.008" thick, with 0.019"x0.031" grating holes. I think it simulates the real grating quite nicely. The pilot holes are there for the steps and grab irons, just very hard to see.
For final prints I will have to sand some of the support sprues off a bit more, but overall I couldn't be happier with the result. I'm very excited about making some minor adjustments and then printing a fleet. I do have two remaining issues. The flat car with a container on it can have a weight placed low to add the necessary mass. I would like to have some empty flats (they will look great painted) but this configuration doesn't have anywhere to add mass. I may look into having a brass casting done, but I'm not sure that could handle the detail and small size of some of the beams.
I could use some help for the final touch - decals. Does anyone know of a good printer (commercial or do it yourself) that can make the smaller N scale details I need for this car? With decals, this print will be able to exceed the quality I've seen in HOn3 models of the same prototype. I will post more about the containers in another post.
