[Will] wanted to build some animatronic eyes that didn’t require high-precision 3D printing. He wound up with a forgiving design that uses an Arduino and six servo motors. You can see the video of the eyes moving around in the video below.
The bill of materials is pretty simple and features an Arduino, a driver board, and a joystick. The 3D printing parts are easy to print with no supports, and will work with PLA. Other than opening up holes there wasn’t much post-processing required, though he did sand the actual eyeballs which sounds painful.
If you are building a CNC machine, a 3D printer, or even a plotter, you have a need for motion in both the X and Y directions. There are many ways to accomplish this, for example, some printers move the tool in the X direction and the bed in the Y direction while others move the entire X carriage in the Y direction and yet more use a delta mechanism. However, one of the oldest means of doing this is the Core XY method. It is interesting because both motors remain stationary and the business end moves entirely on belts or cords. This is similar to the H-Bot technique, but with some differences. [Michael Laws] has a video (see below) that explains how two stationary motors can move a tool anywhere in an XY region.
The idea behind Core XY goes back to at least old drafting tables. You can think of it as an object held by two ends of the same belt. As one end of the belt gets shorter the other end gets longer. The belts are arranged so that motion of one motor causes the tool to move at a 45 degree angle. That means you have to move both motors to go in a straight line.
It’s taken longer than some might have thought, but we’re finally at the point where you can pick up an SLA 3D printer for a few hundred bucks. These machines, which use light to cure a resin, are capable of far higher resolution than their more common FDM counterparts, though they do bring along their own unique issues and annoyances. Especially on the lower end of the price spectrum.
[FlorianH] recently picked up the $380 SparkMaker FHD, and while he’s happy with the printer overall, he’s identified a rather annoying design flaw. It seems that the upgraded UV backlight in the FHD version of the SparkMaker produces somewhat irregular light, which in turn manifests itself as artifacts on the final print. Due to hot spots on the panel, large objects printed on the SparkMaker show fairly obvious scarring.
Now you might expect the fix for this problem to be in the hardware, but he’s taken it in a different direction. These printers use an LCD panel to block off areas of the UV backlight, thereby controlling how much of the resin is exposed. This is technique is officially known as “masked SLA”, and is the technology used in most of these new entry level resin printers.
As luck would have it, the SparkMaker FHD allows showing various levels of grayscale on the LCD rather than a simple binary value for each pixel. At least in theory, this allows [FlorianH] to compensate for the irregular backlight by adjusting how much the UV is attenuated by the LCD panel. He’s focusing on the printer he personally owns, but the idea should work on any masked SLA printer that accepts grayscale values.
The first step was to map the backlight, which [FlorianH] did by soaking thin pieces of paper in a UV reactant chemical, and draping them over the backlight. He then photographed the illumination pattern, and came up with some OpenCV code that takes this images and uses the light intensity data to compensate for the local UV brightness underneath the sliced model.
So far, this method has allowed [FlorianH] to noticeably reduce the scarring, but he thinks it’s still possible to do better. He’s released the code for this backlight compensation script, and welcomes anyone who might wish to take a look at see how it could be improved.
An uneven backlight is just one of the potential new headaches these low-cost “masked” SLA printers give you. While they’re certainly very compelling, you should understand what you’re getting into before you pull the trigger on one.
Considering that it’s only existed for around a decade, the commercial desktop 3D printing market has seen an exceptional amount of turnover. But then, who could resist investing in an industry that just might change the world? It certainly didn’t hurt that the MakerBot Cupcake, arguably the first “mass market” desktop 3D printer, was released the same month that Kickstarter went live. We’ve long since lost count of the failed 3D printer companies that have popped up in the intervening years. This is an industry with only a handful of remaining veterans.
One of the few that have been with us since those heady early days is LulzBot, founded in 2011 by parent company Aleph Objects. Their fully open source workhorses are renowned for their robust design and reliability, though their high prices have largely kept them off the individual hacker’s bench. LulzBot was never interested in the race to the bottom that gave birth to the current generation of sub-$200 printers. Their hardware was always positioned as a competitor to the likes of Ultimaker and MakerBot, products where quality and support are paramount above all else.
NASA’s modified LulzBot
While LulzBot printers never made an impact on the entry-level market, there are institutions willing to purchase a highly dependable American-made 3D printer regardless of cost. The United States Marines used LulzBot printers to produce replacement Humvee door handles in the field, and some of the modifications that were necessary to meet their stringent requirements eventually resulted in updates to the consumer version of the printer. NASA used a highly modified LulzBot TAZ 4 to print PEI at temperatures as high as 500°C, producing parts far stronger than anything that had previously been made on a desktop 3D printer.
Yet despite such auspicious customers, LulzBot has fallen on difficult times. Consumers have made it abundantly clear they aren’t willing to pay more than $1,000 for a desktop printer, and competition above that price point is particularly fierce. Last month we started hearing rumblings in the Tip Line that the vast majority of LulzBot staff were slated to be let go, and we soon got confirmation and hard numbers from local media. Of the company’s 113 employees, only 22 would remain onboard to maintain day-to-day operations. Production on their flagship models would continue, albeit at a reduced pace, and all existing warranties would be honored. But the reduction in staff and limited cash flow meant that the development of future products, such as the LulzBot Bio tissue printer, would be put on hold.
LulzBot wasn’t quite dead, but it was hard to see this as anything but a step on the road to insolvency. A number of insiders we spoke to said they had heard a buyout was expected, and today we can report that the sale of Aleph Objects to Fargo Additive Manufacturing Equipment 3D (FAME 3D) is official. Production of the current LulzBot models is expected to continue, and some of the 91 laid off employees are likely to be hired back, but continuing Aleph Objects CEO Grant Flaharty says the details are still being finalized.
This new financial backing, provided by a venture capitalist, is certainly good news. But it would be naive to think this is the end of LulzBot’s troubles. The market has spoken, and unless the company is willing to introduce a vastly cheaper version of their printer to entice the entry-level customer as Prusa Research has recently done, it’s unclear how an infusion of cash will do anything but delay the inevitable.
For what it’s worth, we hope LulzBot finds some way to thrive. The ideal of building fully open source printers is something near and dear to the heart of Hackaday, but after the loss of PrintrBot, we’re all keenly aware of how difficult it is for small American companies to compete in the modern 3D printing market.
Too often when you see a build video, you only get to see the final product. Even if there’s footage of the build itself, it’s usually only the highlights as a major component is completed. But thankfully that’s not the case with the “V-Baby” CoreXY 3D printer that [Roy Berntsen] has been working on.
Watching through his playlist of videos, you’re able to see him tackle his various design goals. For example he’d like the final design to be both machinable and printable, which is possible, but it certainly adds complexity and time. He also transitions from a triangular base to a rectangular one at some point. These decisions, and the reasons behind them, are all documented and discussed.
Towards the end of the series we can see the final testing and torturing process as he ramps up to a final design release. This should definitely demystify the process for anyone attempting their first 3D printer design from scratch.
We’ve all gotten pretty adept at 3D printing keychains and enclosures. Some people can even 3D print circuit boards to an extent. But the real goal is a Star Trek-style replicator that just pushes out finished products. Printing different components would be a key technology and unless you want to supply external power, one of those components better be a battery or other power source like a solar cell. A recent paper entitled Additive Manufacturing of Batteries explores this technology. The paper is behind a paywall, but you can probably find a copy if you are persistent.
Some of the techniques are pretty exotic. For example, holographic lithography can produce high-performance lithium-ion batteries. However, some of the processes didn’t sound much different than some of the more common printing techniques employed by desktop printers, although with more exotic materials. For example, some batteries can be made with inkjet printing and even fused deposition printing. Continue reading “3D Printing Batteries”→
There are a lot of remarkable uses for optical fiber, chief among them being telecommunications and imaging. While fiber can be produced for a better price than copper wire equivalents, they’re still not easy or cheap to manufacture.
Silica fibers require spinning tubes on a lathe, which requires the fiber’s core to be precisely centered. A new method by researchers based at the University of Technology, Sydney offers a simpler method using additive manufacturing.
There are still challenges in producing silica fiber, however – unlike commonly drawn polymer materials, silica requires high temperatures, up to 1900 degrees Celsius, to 3D print. Past attempts at glass printing using fused deposition modeling with high-temperature nozzles to pump out molten silica have been slowed by the viscosity of molten glass.
In order to overcome the temperature problem, composite materials consisting of a polymer with a lower melting point and silica nanoparticles are used instead. In addition, the researchers opted to use a direct laser writing printer. The technique involves drawing the molten material and pulling out the optical fiber. After the polymer and impurities are debinded and removed, it’s only an issue of sintering the silica to fuse the forms back together.
The method has been used to fabricate a preform that can be used for multi- or single-node fibers. While the technique isn’t perfected quite yet, it holds promise for reduced fabrication and material costs, as well as eliminating labor risks from the lathe-based work.
