From the beginning, the general perception about consumer-grade desktop 3D printers was that they were great tools for prototyping or one-off creation, but any other requirements would be too much. After all, they are too slow, too expensive, and too finicky to be used in a production environment. Once you need multiple copies of plastic parts, you’d better bite the bullet and switch to injection molding.
But of course, the situation has changed a lot since then. Who would have thought that one day you could buy five 3D printers at the cost of the crappy Harbour Freight mini lathe? Modern 3D printers are not only cheaper, they are more reliable and produce higher quality parts. Coupled with software like OctoPrint, managing them becomes a breeze. Today, building a small printing farm and mass-producing parts in an economical way is completely within the capabilities of ordinary hobbyists.
So when I started to see a list of these 3D printed rocket lights on eBay, maybe I shouldn’t be so surprised. Depending on how long you are willing to wait for transportation, you can get lights at various prices from various sellers. These lights come in a variety of shapes and sizes, usually featuring a space shuttle or a powerful Saturn V, perched on an “exhaust plume”. White PLA plastic. There are several orange LED lights flashing in the lamp, which is expected to produce an impressive flame effect, which will delight young and old space enthusiasts.
As a space enthusiast between these extremes, I think it’s worth risking $30 to see how these things look like in real life. After waiting for a month, a crushed box was delivered to my door. I’m pretty sure it will contain a tiny broken version of the majestic lamp I promised-just like the hamburger that McBurgerLand actually gave you. An excuse for sadness, compared to the commercials they made on TV.
But personally, it does look great. The use of internally illuminated 3D printed structures to simulate smoke and flames is something we see in DIY scenes, but implementing it in relatively inexpensive production parts is impressive enough, and I think it deserves careful study.
Now I always think that the best way to see how something is built is to take it apart, so I admit that the following is slightly different from the other teardowns in this series. There is no mystery about flashing a few LEDs among Hackaday readers, so we already know that electronic devices will be extremely simplistic. The interesting part this time is not what is inside, but how the object itself is produced.
I chose the Space Shuttle version of his lamp on Saturn V because it is the harder of the two to produce so far. I know that the iconic orbiter, with its orange outer fuel tank and side-mounted boosters, is more difficult to FDM print than the cylindrical Apollo rocket. Shuttle will almost certainly be printed in multiple pieces and glued together, I want to see what build quality can be expected in the worst case.
But even after a closer inspection of the approximately 120 mm (4.7 in) spacecraft, I have to admit that they did a very good job. Obviously, this work has done a lot of finishing work, especially on the external fuel tank and booster, but the printer used to produce the space shuttle has obviously been dialed in well. You can see the faint layer lines on the orbiter itself, but in my experience, they are always difficult to hide on the white surface. Also note that the windows are not only painted, but are actually tiny dents on the printed surface, as are the RCS thrusters on the nose.
In terms of production, the orbiter appears to be printed separately from the fuel tank and booster, and then glued after the parts are painted. Obviously, all parts are printed vertically, which is a bit surprising because the logical printing direction of the orbiter is to let it lie flat on the bed.
Quite a lot of support material must be used to print the orbiter vertically, and the remnants of it can be seen on the stepped surface on the back of the wing. I don’t know why they would take this more difficult route, although they may be printing them vertically to maximize the amount that can be put on the bed at a time.
Although my 3D printer owner was very impressed with the quality of the final work, my space fans have to say that this is not a particularly good interpretation of the space shuttle. The wingtips are all wrong, there is no OMS propeller on the back, and the nose looks more like a sad cartoon dog than a legendary space plane that NASA has flown for three years. Of course, the children living in the room with this lamp may not know this.
See the sun
Although the space shuttle itself is impressive, the PLA plume it carries is clearly not so impressive. Paint plastic will reduce the luminous effect, but the disadvantage of not painting is that even small surface inconsistencies are obvious. Close inspection will reveal obvious signs of insufficient extrusion, which usually indicates that the printing speed exceeds the capacity of the extruder to melt the amount of plastic required.
Things are only worse internally. There is no internal support structure when printing the plume to save time and materials. Although it works well in most cases, there are still some areas that are almost impossible to print. A patch near the bottom is severely deformed, and it looks like it may have been scratched on the extruder because of signs of discoloration and charring.
In general, the printing speed of my impression of the plume is much faster than the space shuttle itself. They can even be printed on a second set of printers that are not strictly maintained and calibrated because they do not need to be close to any details of the “hero” spacecraft paired with them.
light up the candle
As you might suspect, the electronics inside the lamp is not worth the excitement. The small PCB has eight LEDs (four red and four yellow), driven by an unlabeled 8-pin IC, and thermally bonded directly to the top of the 800 mAh soft pack battery.
A smaller circuit board is responsible for charging the battery with a standard micro USB cable, and has an LTH7 battery management IC. Ordinary readers may remember the last time we saw it used in the power circuit of some very bloated restaurant pagers. The charging module may seem to be modified from other devices, but the one-trick feature of the LED board makes me think it is designed for these lights.
Money can make ghosts grind
To me, all parts of this lamp are produced using standard consumer 3D printers, which seems clear, because there is nothing here that the entry-level Ender 3 cannot do. But what about material costs? Well, this particular style of lamp weighs about 160 grams, and since we know from the attached document that it is printed in PLA, we can easily calculate some interesting indicators.
In other words, considering that the current consumer PLA price is about US$20 per kilogram, running each filament will consume 52 meters of filament, and the cost is about US$3.20. Although this does not take into account the support materials required to print Shuttle, we can also bet that the company that prints these lamps does not pay the full retail price for its filaments. Even if the occasional erroneous prints can bias the numbers, it is safe to say that the material cost of each of these lights is much less than $4.
Given China’s notoriously low labor costs, and the minimal cost of the simple electronic equipment required to assemble them, a substantial profit can be made for only $30 per lamp. Such an operation can quickly recoup the cost of the initial printing plant. At this time, the only ongoing costs will be the newly supplied PLA, batteries and LEDs.
In short, it looks like we are all wrong. Or at least, there is not enough imagination to predict the huge leap that desktop 3D printing will achieve in ten years. Although it may be a bit far-fetched to say that it is an ideal solution, products like this prove that not only can print farms that consume 3D printers produce production-ready parts, but they may make you hell money for many people to do.