3D printing hands on: Working with wood
The materials you can use to produce 3D prints have exploded over the past few years. One of those materials is wood (or "wood"). Having been provided a spool of filament, I decided to put it through its paces.
Before we begin, I should probably put all my cards on the table and come clean with you. I took wood shop back in the day, and Poppa Gewirtz did his best to teach me some woodworking basics. I haven't tried making anything from wood since then. So, when I tell you I'm going to try to sand and finish the 3D-printed wood parts, remember that, "Dammit, Jim, I'm a computer scientist, not a woodworker."
What is wood filament?
The folks at Aleph Objects, makers of LulzBot printers, were kind enough to provide me with a spool of ColorFabb Woodfill. To be clear, a wood filament is not a filament made out of wood. The 3D printer still needs to melt, and then extrude a plastic polymer substance. What filament makers are doing is trying to mix in other substances (like, in this case, wood fiber). This particular filament uses about 70 percent PLA plastic and 30 percent wood fiber.
If you think about it, the filament needs enough plastic material to allow each layer to adhere to the previous one. The filament needs to be pressed and squished through the very tiny printer nozzle, but it also needs to have enough of the non-plastic material to provide the feel (and in some cases, the properties) of the specialized material.
For example, there are some steel or iron materials in production that simply look like steel and iron. Others are heavy and exhibit ferromagnetic properties (in other words, magnets will stick to them).
Hands-on with wood filament
The first thing I did was open the package and load the printer. As you can see below, the filament looks a lot like strands of cardboard.
Here's the wood filament from ColorFabb.
I needed something to test print. Because I wanted to see if the filament could be finished like wood (more on that in a bit), I wanted a design that would be easy to sand and finish.
I originally thought I'd make a wood version of my old rectangles tray design I demonstrated early on in this 3D Printing Discovery Series, but I had no idea how well I'd do getting into the tight corners of the design.
Therefore, I decided to design a bowl, which you can see below. In the video that accompanies this article, I'll show you how to make that design in 123D Design. I'll also show a second design that had a bunch of circles around the outside. Unfortunately, it looked terrible. One of the circles was too deep, and a hole punched through. You can download my bowl design from Thingiverse if you want to print it out in your favorite filament.
This is the bowl design produced in 123D Design.
Once I finished the design, I used Cura to slice it. Then I sent it to OctoPrint. I stopped one of the prints early so I could show you how it looked with infill. As you can see, it has an interesting texture, but it still has the structure of a typical 3D print inside the walls.
Here's inside the wood filament print.
My next idea was to sand and finish it. I bought a lacquer finish and some Danish oil from the local home store. I didn't think to get either with a stain color, so they pretty much left the wood filament in its original molded cardboard-looking color.
The video shows you my adventures with staining. Neither stain was much of a success, although the Danish oil, along with the sanding, did manage to remove most of the stratification lines from the bowl. Unfortunately, where Danish oil apparently is supposed to soak into regular wood and protect it, it didn't do so well on the 3D print. The print is still very oily to the touch, even after allowing time for it to set and dry.
UPDATE: After about five days sitting in an 80-degree garage, the oily feeling has pretty much left the bowl, and it now seems rather nice. I imagine that if I used a stain, it would look even nicer, but on a wooden table, it fits in well. If you use sanding and Danish oil, definitely allow for a week or so of drying time, but I think it might well work.
The less said about the lacquer, the better. Suffice to say that when they suggest a well-ventilated area, they're probably right. I did eventually decide to open the garage door, raising the temperature from an uncomfortable 80 (even with my air conditioner going full blast) to a more tropical 97.
Yeah, that's Florida in the summer. Worse, even with the garage door open, the toxic stink didn't seem to leave the garage for a day or so. Good times.
In any case, here's what the bowl finished with Danish oil looks like after my handiwork.
This is a sample bowl finished with Danish oil.
Here's what the bowl finished with lacquer looks like.
This is a sample bowl finished with lacquer.
Both, frankly, look better in their photos than they do in real life. You can see a bit of what seems like wood grain in the Danish oil finish, but that's not really visible to the naked eye. The photo of the lacquer finish doesn't show the puddles of lacquer that somehow appeared on the side of the bowl due to some over-enthusiastic spray passes.
Is it wood yet?
What of the wood-ness? Is it wood, or not? My wife says it still looks like plastic, although I think it resembles a molded cardboard form like the one below:
Molded cardboard form originally used to roll garage door insulation.
It definitely doesn't look like a piece of fine woodworking, although my new friend Rob over at Instructables shows how he created a statue. As you can see in the following picture, it definitely looks like a finished wood carving.
Image: Rob at Instructables
Printing was easy, and the objects are pleasant to hold. The filament is relatively expensive compared to non-specialty filaments, so it would be impractical to print everything using this stuff. I also haven't yet tested how strong it is compared to traditional PLA or ABS, or how well the layers hold together. I certainly wouldn't recommend building anything that might need structural strength using this material.
That said, this was at the very high end of the cool scale. I'm really curious about how other specialty filament materials perform. I would definitely recommend you try it, and share your experiences in the TalkBacks below.
For those with more woodworking or crafting skill (my crafting skill is limited to engineering and mining in World of Warcraft), there's no doubt this is another material for your kit bag. If you're experimenting and exploring 3D printing, I encourage you to try wood filament. It's definitely worth a tinker.
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