Friday, June 26, 2015

Don't Trust Robert's Advice on 3D Printed Buildings

In the past, I've declared that 3d printing isn't great for buildings. Most buildings are easy to make using sheet styrene or sheet wood - I can probably build them faster than I could draw them on the computer. I only need one copy of a particular building, so the ability to print multiple copies isn't so interesting. Buildings tend to be large; they're either slow to print, or won't fit at all in the 3d printer. I'll admit I've used the 3d printer to make details (such as the architectural details for the Market Street station, or the freight doors I borrowed from the Guggenhime packing house. But buildings? Not worth the trouble.

Well, actually, sometimes the 3d printer can help with buildings, and two recent projects highlight when the printer might come in handy.

J. S. Roberts and clerestory windows Early 20th century buildings often used clerestory windows - raised sections of roof with small windows - as a way to bring light into the center of a building. We usually think of this with sawtooth roof factories, but you'd also see this in frame structures. The J. S. Roberts packing house off San Carlos Street got light into the fruit sorting area on the third floor with a raised roof and some small windows, all above the barn-like building's normal roof line.

J.S. Roberts clerestory windows

Clerestory windows like this are a pain to scratchbuild. There's not a lot of good, tiny window castings if you're trying to model a strip of two foot high windows. Because the clerestory roof is often only raised a couple feet, building the walls around the window can be difficult. If the clerestory is on a peaked roof, then I've also got to cut the ends to match the roof slope precisely. The last time I did a model like this, I used some 3d printed blocks to form the clerestory section, but still had to cut the lapped siding sheet to fit. For that model (the Earl Fruit Company packing house on Ryland St.), I wasn't completely happy with the overall clerestory look (too few windows, clerestory section too tall), but I decided it would do.

When I completed the main section of the J.S. Roberts packing house, I knew I needed to make another clerestory roof to finish the project. However, the 1930's photos I'd seen showed a very short space between the two roofs. I couldn't think of any commercial windows that would work, and I knew the whole assembly would be tedious to build.

Clerestory 3d model

Roof and access hatch

Instead, I cheated - I sketched the whole clerestory roof - siding, windows and all - as a single piece. I didn't have to worry about cutting the angles against the roof (as long as I measured the angle correctly.) I could size the windows to exactly match the space. I did have to draw out the location of *every single board* for the siding - tedious, but doable on this relatively small model. The result was too big for the printer, so I split it in two, printed two copies, and glued the pieces together to make a completed clerestory assembly. After painting and attaching corrugated siding for a roof, I was done. The windows, although solid, got some black gloss paint to make it look like there really was glass in those panes. The result was just right - a roofline that matches the prototype and I didnt have to cut any fussy angles.

In fact, I was happy enough with the result that I did another 3d print for the access hatch on the roof. Again, by 3d printing it, I didn't have to worry about cutting the correct angle into plastic siding, and didn't have to worry about fabricating a tiny box perfectly square.

Campbell passenger shelter for the Peninsular Railway

The Sourisseau Academy, one of the local history organizations in San Jose, posted a picture recently of downtown Campbell in the 1920's. The photo, showing the area around the railroad tracks and Campbell Ave., reminded me that the former Peninsular Railway, an interurban line, used to go from downtown San Jose to downtown Los Gatos via Campbell. The tracks cut through the new suburbs of Willow Glen and turned here and there through orchards. Just before the tracks reached downtown Cambpbell, they curved off Campbell Ave. and onto Railway Ave to pass next to the old S.P. depot. The Sourisseau's photo shows Campbell Ave. at Railway Ave. - the curve of the interurban tracks, the overgrown mess of the SP's former garden at the intersection, and a small passenger shelter at the intersection which must have been handy both in the rain and on really hot days in summer. (The photo is visible in the Sourisseau February 2015 video, showing the interurban tracks turning south onto Railway Ave.)

Now, the passenger shelter wasn't much - a bench for a couple people, simple siding, and some minor architectural details to please the town burghers. It's also exactly the sort of model that's easy to make in styrene with a couple hours work. I was still curious whether I could make one in 3d, and did some quick sketches.

Applying the siding was the annoying part; rather than just pulling some lapped siding sheet out of a drawer, I had to draw each board: correct spacing, correct overlap at the bottom, etc. The rest was pretty trivial, with the hardest part being the choice of how to print the model. (I chose to print it upside down, with the roof having the bad surface where the model attached to the 3d printer.) Some filing, and some Campbell shingles completed the model. It's not much, but it showed me that I could create small structures quickly. More importantly, I got to play around a bit with the design and experiment with the decorative eave ends. For my layout, 3d printing the shelter is a bit of overkill, but if I needed three or four, it might have been a suitable project for 3d printing.

I still think 3d printing isn't particularly useful for 3d structure models, but these two projects reminded me that 3d printing could still be handy either for work that would be challenging to do by hand, or where I wanted to experiment with details or shapes.

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