My First 3D Model

Posted:
Tags: #3d-printing

This may come as something of a surprise, but: back in high school, I was kind of a nerd. (To be clear, I still am a nerd; but the point is that I was also a nerd then.)

I had—still have—a pocket-sized magnetic chess set that I used to carry around. I would play with friends during lunch, and occasionally against teachers when the opportunity arose.

Three-quarter view of a pocket-sized magnetic chess set in starting position, from White's queenside perspective. The set features 14mm squares and a 23mm king height.
The magnetic chess set in question.

One day, probably about fifteen years ago, I was dismayed to discover that I had lost one of the white rooks. And yet, eagle-eyed readers will note that there are not one, but two white rooks in the photo above. And no, it’s not an old picture: the EXIF metadata will tell you that it was taken on , and with a 3rd-generation iPhone SE—which certainly did not exist in 2010.

What sorcery is this?

Star Trek replicators are real now, provided that the thing you want is made of plastic and you are willing to wait several hours for it1

I’ve been vaguely interested in 3D printing for years, but I never had anything specific I wanted to do with a 3D printer, and so I never felt I could justify the expense. It was just one of those things that seemed like it might be cool to have, someday.

Well, it turns out that having a Mastodon feed filled with hardware hackers and retrocomputing enthusiasts is a fantastic way to come up with a whole host of reasons why you do, in fact, need a 3D printer in your life.

Couple that with the then-impending 2024 holiday season and the discovery that Bambu Lab—a company whose printers, so far as I could tell, were notorious for their high quality and ease of use—had two entry-level models (A1, A1 Mini) for $360ish and $220ish USD,2 respectively, and it felt like perhaps the stars had finally aligned.

Bambu Lab A1 3D printer, in the process of constructing a 15mm white rook. The printer consists of a rectangular base; a square 256mm by 256mm build plate, which moves back and forth to constitute the Y-axis; a vertical frame straddling the base, supporting a gantry that moves up and down to constitute the Z-axis; and a rectangular tool head that moves left and right on the gantry, constituting the X-axis. A 1kg spool of filament is mounted above the Z-axis frame, and a small touchscreen beside the build plate displays the model being printed.
The Bambu Lab A1, dutifully printing a new rook.

I consider myself fortunate to have had enough family members willing and able to chip in to purchase the larger of the two, the A1, for Christmas.

Alas, it arrived a week late; and as I live on the opposite side of the state from most of them, it wasn’t until mid-February that I had the opportunity to visit again and pick it up. (I mention this only to point out that, for once, I’ve managed to write about something I did without several months passing in the interim.)

The first couple things I printed were (community uploaded) models from Bambu Lab’s own MakerWorld website. You can actually see them in the picture above: the cable guide on the right, which keeps the toolhead cable from drooping as much; and the paddle on the left, which deflects the little blobs of waste filament that the printer sometimes ejects so they land on top of the dresser instead of falling behind it.

Manifesting physical objects into existence through sheer force of will3

Replacing my lost rook was one of the first project ideas I had. But, while I could have easily printed a rook—maybe even a rook that was about the right size—I harbored no illusions that I would be able to find a ready-made model that actually looked like it belonged in my set. I knew that I would have to design one myself; but seeing as I had precisely zero experience with 3D modeling, I figured it was going to be a while before I got to that point.

The printer came with a 20g sample of white PLA filament, more than half of which I used for those first few objects. I neglected to order any additional filament ahead of time, so I soon found myself in a position where I wanted to do 3D-printing-related activities but couldn’t actually print anything. In a way, I think this actually worked out for the best: it gave me adequate motivation to actually move forward with the rook project while I waited for my filament order.

This video taught me just enough about FreeCAD4 to get started.5 (I am not going to go into detail about how to use FreeCAD in this post.)

Part Design view in FreeCAD. The majority of the window is dedicated to a three-dimensional rendering of a rook.
The FreeCAD Part Design view, showing a three-dimensional rendering of my rook model.

My first iteration, shown above, looked pretty good in the render; but it didn’t quite work out when confronted with the constraints of physical reality. Not pictured is the 10mm circular cutout in the base to fit the magnet I scavenged from some fancy gift card packaging. I suspected that might be too large a gap for the printer to bridge without making supports, but I decided to try it anyway and see what happened.

Close-up view of three 15mm white rooks, arranged side-by-side on the magnetic chessboard. The center rook is the injection-molded original, while the other two are 3D-printed. The left rook looks nearly identical to the original, while the right rook has several imperfections; most obviously a large hole in the base where the printer was unable to bridge across the gap where the magnet belongs.
The surviving original rook (center), flanked by my first (right) and second (left) attempts at replicating it.

Ten millimeters did, in fact, prove too far to bridge; the roof of the magnet cutout partially collapsed. Yet, amazingly, enough of the base held up that the printer was able to finish the model.

For the second iteration, I increased the slope of the base so that the interior wall could slope upwards at a 45° angle until the remaining gap was narrow enough to bridge more successfully. I also tweaked a few other details to better resemble the original rook: I reduced the distance between the middle ridges and the upper one, made the upper ridge more prominent, and widened the sort of double-cone shape just above the base. It was also in between the first and second print attempts that I learned how to use the variable layer height feature in Bambu Studio6 to achieve substantially better definition on fine details vs. the flat 0.2mm layer height I used for the first attempt.

The second model isn’t a perfect replica, of course—close examination will reveal some minor differences, not least of all the shade of (off-)white. But, at a glance, it is very nearly indistinguishable from the original, and I really could not be more pleased.

Footnotes

  1. The rook is quite small—consuming only half a gram of filament—and only took 17 minutes, the first five of which were the printer’s warm-up and calibration routine. It is easy to get into multiple-hour print times for medium-sized objects, though, especially if you prioritize print quality over speed. ↩︎

  2. These were sale prices; the regular prices are slightly higher, but still more affordable than I would have guessed. ↩︎

  3. Okay, that’s a slight exaggeration. But, that is kind of what it feels like to design something from scratch and then see it made real. ↩︎

  4. In another incident of serendipity, it turns out that FreeCAD had just hit 1.0 in November 2024, after more than twenty years of development. ↩︎

  5. I intend to watch the rest of the series sooner or later, but that one video contained almost everything I needed, and a few web searches provided the rest. ↩︎

  6. A fork of PrusaSlicer; itself a fork of Slic3r. Bambu Studio has also been forked to create OrcaSlicer. ↩︎