Saturday, May 25, 2013 diorama part one is having a diorama contest, and I will have several blog entries on the 3d printing portion of the project...this being the first.  For HO scale, the contest is limited to 36 square inches, and I went the simple route, and did mine 6" x 6".  The rules were pretty simple, and can be viewed at should anyone really care. 
My concept was to model the back of three townhouse/row house units that backed up against the tracks, this being the first concept drawing.  The blog entry will cover the right most unit, the unit features a metal standing seam roof, and a dormer.

This is one of my early drawing.  My main interest was to learn more about 3d printing model railroad structures, and getting these done in time to use in clinics I am presenting at the Mid-Continent NMRA in a few weeks. 

As is normal on a new design, it takes several attempts to get everything correct to print.

Here is the roof sections in a trial assembly. 

This was printed in several pieces,  The main walls were done in three sections, foundation, first floor and second floor.  They could have been printed at one time, but the length of time to print it was prohibitive for me.  The top floor alone took over two hours to print.

Each door and window is an individual piece, although they were all printed at the same time.  The roof and dormer is made up of three pieces, plus the window, and then the steps are one piece.
     In order to form the blocks, I actually drew individual block, and they are each printed separately.  But, because they are printed touching each other, the melt together a little.  In this case, I used one of the possible negatives of this type of printer to my advantage.  This does add to the print time, but while the wall is printing, I work on some other project. 
     I used clear transparency film for the windows and printed the blinds on paper.  Someone on kitforum had a pdf I downloaded of blinds, and they printed out well.
Next time I will cover the middle unit.

Monday, May 20, 2013

Slab Siding Cabin update

I did not like the pictures in the previous post, so I took some better ones.  This is just a temporary roof, as I plan on installing BEST "wood" shingles.

I will obviously adding a post to the corner to hold up the porch roof.  Also a foundation.

Thursday, May 9, 2013

Slab log siding on cabin, 3d Printed, HO scale

This idea came from an article in the Short Line and Narrow Gauge Gazette, July-August, 2008. I would show a copy of it here if it wasn't for those pesky copyright laws.

As usual, I did the drawings in sketchup, then converted the drawings to stl files for printing.

Here is a view from the front.  I only drew one gable end, as the same size will work on both ends.
When it came time to print it, I decided it would be be to print the sides laying down.  This, hopefully, would take advantage of the layering that is just part of the printing process.  I thought, and it turns out, rightfully so, that the layering would give me some vertical graining.
Here is the front wall, which was my test print.  I painted it with a dark brown, the weathered it with washes of gray and black India ink/alcohol.  After several coats, I ended up with something that would work.
This is one of the few times where the test print worked, and I did not have to redesign and reprint before moving on to the full project.  Actually, if I did it again, I would handle the structure corners differently.  I mitered them, most with a shoulder miter.  Since the printer is extruding ABS plastic at 250 degrees Celsius, everything has a slight rounding to it.  Because of that, the shoulders have a fillet in them and really do not allow the corners to fit tight without some carving.  It is easy to carve, much easier than metal castings, but it I did it again, would make the corners square.

As the material is ABS, it will solvent weld with Methylene Chloride.  Also, you can glue styrene to the ABS.  I used styrene for bracing and roof supports.  Obviously, I am going to install a roof, and add a rock foundation.  The foundation will probably be printed, but I will cover that, at a later date.
I plan on using this as the office for one of several logging operations on the planned HO model railroad.

My goal, for the blog, and for my model railroad hobby, this year, was to do enough modeling, and find enough time, to do a blog post every week.  I am way behind, but I am going to try and catch up in the next two months. 

Saturday, May 4, 2013

Outside entrance stairs for HO Scale structures, 3D Printed on the Afinia

Wow, I am getting way behind on my posts.

This is one of many items I thought I would print at shapeways, then I checked the cost, and said no.  But, when I got a 3d printer, the cost went back down, and I have now designed several different types or styles.  This is exactly why I wanted a 3d printer to use in model railroading.  Structures and larger parts are quite economical.

This is an overview of the stairs I have printed so far.  Some of these have a few parts added, and all have either primer or an alcohol and ink wash on them to show the details.

This what the stairs look like as they come off the printer, except the styrene uprights were added at this time to give support to the structure as it is removed from the printing platform, and as the raft is removed.  The raft is the plastic extruded under the part that adheres it to the printer base plate.  Also in this view, you can see the support material on the near end.  I looks like crap, but is will peel off easily, as it is only there to provide support for the battens that were printed horizontally on this side/
Viewing from this end, we can see the support material that holds up the window wall. This will also have to be removed, but being a small area, it is usually easy to do.
Here is a totally enclosed stairway, which is my favorite. 
The only issue with this print is the amount of support material that need to be removed.  From this view, you can imagine the amount of material that it took to support the wall being formed. 
It really paints up well, and with a little touch up will fit many a structure on just about any era model railroad.

On the inside, however, you can see the damage I cause when I removed the support material.  Since it is up inside the piece, no one will ever see it, but still is can be an issue.  I have done some web research on this problem, and one suggestion was to pause the print once the support is built, but before the final part starts to print.  You have to be watching really careful to catch it at the right moment, and know how many layers of raft are put down on top of the support material before the final object starts to print, BUT if you catch is at that moment, pause it, spit on your finger (no, I am not kidding), wipe the spit on the raft, and continue the print, the raft peels of MUCH easier.  Sounds kind of stupid, but I have tried it several times now, and it works.

The vertical and angled pieces are styrene, solvent welded to the ABS that was printed.  I add these before the part is removed from the rafts, as it makes the part more stable, since without these pieces, the roof and stairs are only connected at one end.

I am working on a three building background diorama for a build contest at, and I have several other projects that I should be posting some pictures in the next week.  I also have three clinics on 3d printing I need to put together for the Mid-Continent Region of the NMRA that is coming up in June.  More on model railroading and related 3d printing soon.