[3DPrintFarm] got an early version of the Phrozen Sonic Mini resin printer. If you look at the video below, he was very impressed with its build quality and results. The price is reported to be $200, although we have seen it on some web sites for a bit more. The build quality does look good, although you have to admit, the motion mechanism on a resin printer is pretty simple, since you just need to move up and down.
The printer uses a monochrome LCD which allows it to cure layers very fast (apparently, monochrome panels pass more ultraviolet light through). The panel also has a higher-rated lifetime than color LCDs
University of Toronto researchers have succeeded in converting used cooking oil — from McDonald’s, no less — into high-resolution 3D printing resin. Your first response might be: “Why?”, but thinking about it there are several advantages. For one thing, waste oil is a real problem for the food industry, and thus it can be acquired rather cheaply. An even bigger benefit is that the plastic that originates from this oil is biodegradable. Their 3d-printed butterfly, of course, is made from the recycled resin.
We aren’t chemists, but apparently 3D resin has a lot in common with cooking oil already. The team used a one-step chemical process to convert one liter of McDonald’s greasiest into a little more than 400 milliliters of resin.
[Bunnie Huang] has shared with all of us his utterly detailed teardown on the Form 3 SLA printer from Formlabs (on the left in the image above) and in it he says one of the first things he noticed when he opened it to look inside was a big empty space where he expected to see mirrors and optics. [Bunnie] had avoided any spoilers about the printer design and how it worked, so he was definitely intrigued.
Not only does the teardown reveal the kind of thoughtful design and construction that [Bunnie] has come to expect of Formlabs, but it reveals that the Form 3 has gone in an entirely new direction with how it works. Instead of a pair of galvanometers steering a laser beam across a build surface (as seen in the Form 1 and Form 2 printers) the new machine is now built around what Formlabs calls an LPU, or Light Processing Unit, which works in conjunction with a new build tank and flexible build surface. In short, the laser and optics are now housed in a skinny, enviromentally-sealed unit that slides left and right within the printer. A single galvo within steers the laser vertically, as the LPU itself moves horizontally. Payoffs from this method include things such as better laser resolution, the fact that the entire optical system is no longer required to sit directly underneath a vat of liquid resin, and that build sizes can be bigger. In addition, any peeling forces that a model is subjected to are lower thanks to the way the LPU works.
Details about exactly how the Form 3 works are available on Formlabs’ site and you can also see it in action from a practical perspective on Adam Savage’s Tested (video link), but the real joy here is the deeply interesting look at the components and assembly through the eyes of someone with [Bunnie]’s engineering experience. He offers insights from the perspective of function, supply, manufacture, and even points out a bit of NASA humor to be found inside the guts of the LPU.
[Bunnie] knows his hardware and he’s certainly no stranger to Formlabs’ work. His earlier Form 2 teardown was equally detailed as was his Form 1 teardown before that. His takeaway is that the Form 3 and how it works represents an evolutionary change from the earlier designs, one he admits he certainly didn’t see coming.
Remember those actions movies like The Fast and the Furious where cars are constantly getting smashed by fast flying bullets? What would it have taken to protect the vehicles from AK-47s? In [PrepTech]’s three-partDIY compositevehicle armor tutorial, he shows how he was able to make his own bulletproof armor from scratch. Even if you think the whole complete-collapse-of-civilization thing is a little far-fetched, you’ve got to admit that’s pretty cool.
The first part deals with actually building the composite. He uses layers of stainless steel, ceramic mosaic tiles, and fiberglass, as well as epoxy resin in order to build the composite. The resin was chosen for its high three-dimensional cross-linked density, while the fiberglass happened to be the most affordable composite fabric. Given the nature of the tiny shards produced from cutting fiberglass, extreme care must be taken so that the shards don’t end up in your clothes or face afterwards. Wearing a respirator and gloves, as well as a protective outer layer, can help.
After laminating the fabric, it hardens to the point where individual strands become stiff. The next layer – the hard ceramic – works to deform and slow down projectiles, causing it to lose around 40% of its kinetic energy upon impact. He pipes silicone between the tiles to increase the flexibility. Rather than using one large tile, which can only stand one impact, [PrepTech] uses a mosaic of tiles, allowing multiple tiles to be hit without affecting the integrity of surrounding tiles. While industrial armor uses boron or silicon carbide, ceramic is significantly lower cost.
The stainless steel is sourced from a scrap junkyard and cut to fit the dimensions of the other tiles before being epoxied to the rest of the composite. The final result is allowed to sit for a week to allow the epoxy to fully harden before being subject to ballistics tests. The plate was penetrated by a survived shots from a Glock, Škorpion vz. 61, and AK-47, but was penetrated by the Dragunov sniper rifle. Increasing the depth of the stainless steel to at least a centimeter of ballistic grade steel may have helped protect the plate from higher calibers, but [PrepTech] explained that he wasn’t able to obtain the material in his country.
Nevertheless, the lower calibers were still unable to puncture even the steel, so unless you plan on testing out the plate on high caliber weapons, it’s certainly a success for low-cost defense tools.
Anyone who’s tried to encapsulate something in epoxy resin knows how much of a hassle air bubbles can be. If you’re trying to get a perfectly clear finish, the last thing you want is a bunch of microscopic bubbles frozen in time. The best way to prevent this is to put the parts in a vacuum chamber so all the air works its way out before the epoxy cures, but that’s a considerable investment for a one-off project.
But assuming your parts are small enough, [Jasper Sikken] has a great tip that allows you to construct a simple vacuum chamber for just a few dollars. He shows his homemade chamber off in the video after the break, and we think you’ll agree that the change between before and after is pretty dramatic. The best part is that if you want to build your own version, you only need two parts.
The first one is a airtight container large enough to hold the piece you’re working on. Remember that the larger the chamber is the more time it will take to pump down to a suitable vacuum, so avoid the temptation to use something larger than necessary. [Jasper] used a glass jar with a locking lid, which is not only cheap and readily available, but has a decently large internal volume.
Obviously, the second component is the vacuum pump itself. This might normally be a tall order, but [Jasper] recently found that you can buy small battery-powered gadgets designed for sucking the air out of food containers for as little as $5 USD from the usual import sites. All you need to do is pop a hole in the lid of your container, hold the device over the hole, and watch the magic.
Valves (tubes) certainly have a die hard fan base in the electronic community, praised for their warm sound, desirable distortion characteristics and attractive aesthetic. However, sometimes you just want the look of a valve for a prop or a toy, without actually needing the functionality. For those cases, this project from [Ajaxjones] might be just the ticket.
The build consists of taking an existing valve, combining it with a 3D printed base, and using this to create a silicone mould. 3D printed parts and dressmaker’s pins are then used to create the internal parts of the valve, and are inserted into the mould. Clear resin is then degassed, and poured into the mould to create the part. Once cured, the part is removed and the base painted to complete the look. An LED is then installed into a void in the base to give the piece a warm glow as you’d expect.
It’s a simple tutorial to producing high-quality clear plastic parts, and one that should prove useful to many prop builders and cosplayers alike. If you’re wanting to take your resin game to the next level, consider trying some overmolded parts. Video after the break.
When it comes to hobby-level 3D printing, most of us use plastic filament deposited by a hot end. Nearly all the rest are using stereolithography — projecting light into a photosensitive resin. Filament printers have typical build volumes ranging from 1,000 to 10,000 cubic centimeters and even larger isn’t unusual. By contrast, SLA printers are often much smaller. A 1,200 CC SLA printer is typical and the cheaper printers are sometimes as little as 800 CCs. Perhaps that’s why [3D Printing Nerd] (otherwise known as [Joel]) was excited to get his hands on a Peopoly Phenom which has a build area of over 17,000 CCs. You can see the video review, below.
He claims that it is even bigger than a Formilab 3L, although by our math that has a build volume of around 20,000 CCs. On the other hand, the longest dimension on the Peopoly is 40 cm which is 6.5 cm longer than the 3L, so maybe that’s what he means. Either way, the printer is huge. That’s nearly 16 inches which is big even for a filament printer. Regardless of which one is bigger, the Peopoly is certainly much less expensive coming in at around $1,800 versus the 3L’s almost $10,000 price tag.