Last time we checked in with [CrafsMan] he had bought a benchtop injection molding machine. This time, he shows off how to 3D print molds. If you have ever had to spend to make tooling for injection molding, you’ll appreciate being able to make molds relatively inexpensively.
To test his workflow, [CrafsMan] created a little 3D figurine and brought it into TinkerCad. From there he created a mold and used Lychee Slicer to print it using resin.
3D printing is all well and good if you want one of something, but if you want lots of plastic parts that are all largely identical, you should consider injection molding. You can pay someone to do this for you, or, in true hacker fashion, you can build an entire injection molding setup in your own garage, as [Action BOX] did.
The build relies on a pair of beefy 3hp motors to drive the screw-based injection system. These are responsible for feeding plastic pellets from a hopper and then melting them and filling the injection reservoir, before then forcing the hot plastic into the mold. Further stepper motors handle clamping the mold and then releasing it and ejecting the finished part. A Raspberry Pi handles the operation of the machine, and is configured with a custom Python program that is capable of proper cycle operation. At its peak, the machine can produce up to 4 parts per minute.
It’s an impressive piece of industrial-type hardware. If you want to produce a lot of plastic things in your own facility, a machine like this is very much the way to go. It’s not the first machine of its type we’ve seen, either! Video after the break. Continue reading “A Plastic Injection Machine You Can Use At Home”
Glass is one of humanity’s oldest materials, and it is still used widely for everything from drinking vessels and packaging to optics and communications. Unfortunately, the methods for working with glass are stuck in the past. Most methods require a lot of high heat in the range of 1500 °C to 2000 °C, and they’re all limited in the complexity of shapes that can be made.
As far as making shapes goes, glass can be blown and molten glass pressed into molds. Glass can also be ground, etched, or cast in a kiln. Glass would be fantastic for many applications if it weren’t for the whole limited geometry thing. Because of the limitations of forming glass, some optic lenses are made with polymers, even though glass has better optical characteristics.
Ideally, glass could be injection molded like plastic. The benefits of this would be twofold: more intricate shapes would be possible, and they would have a much faster manufacturing time. Well, the wait is over. Researchers at Germany’s University of Freiburg have figured out a way to apply injection molding to glass. And it’s not just any glass — they’ve made highly-quality, transparent fused quartz glass, and they did it at lower temperatures than traditional methods. The team used x-ray diffraction to verify that the glass is amorphous and free of crystals, and were able to confirm its optical transparency three ways — light microscopy, UV-visible, and infrared measurements. All it revealed was a tiny bit of dust, which is to be expected outside of a clean room.
Continue reading “Injection-Molded Glass Breakthrough Shatters Ceiling Of Work Methods”
This mass manufacturer movement towards electric cars is one thing, but what about sustainability on the plastic part production line? Ford and HP have teamed up to turn used 3D printed parts and powders into pellets that will be fodder for injection-molded parts — specifically the fuel-line clips for Super Duty F250 trucks.
According to Ford’s press release, their goal is to reach 100% sustainable materials in all their vehicles, not just the diesel-drinking Super Duty. Their research team found ten other Fords whose existing fuel-line clips could instead be made sustainably, and the company plans to implement the recycled plastic clips on all future models.
There are all sorts of positives at play here: the recycled clips cost 10% less to make and end up weighing 7% less than traditionally-made clips, all the while managing to be more chemical and moisture resistant.
And so much plastic will be kept out of landfills, especially once this idea takes off and more manufacturers get involved with HP or form other partnerships. One of the sources of Ford’s plastic is Smile Direct Club, which has 60 printers cranking out over 40,000 dental aligners every day.
There’s more than one way to combine 3D printing and sustainability. Did someone say fungal sound absorbers?
[Images via Ford]
While 3D printing has now become easily accessible and cheap, there are still several use cases where you need the advantages offered by injection molding, even for small batch runs. Professional small-batch injection molding can be pretty expensive, and buying a manual machine can cost quite a bit. Of course, there are a number of DIY injection molding projects to choose from, but they usually involve a fair amount of tools and labour. [Bolzbrain] wanted to bypass all of the heavy cutting, welding and frame assembly work, so he’s built himself a DIY Injection Molding Press for cheap using an off the shelf, six ton hydraulic press. At final count, he ended up spending about €150 for the machine and another €120 for tools to build the machine. He also managed to locate a cheap, local CNC service that gave him a good deal on machining the Dies. But of course you can’t put a price on the lessons learnt and the satisfaction of having built it by hand.
Choosing the hydraulic press is a great idea as it provides the high pressure needed for the job without the operator having to exert a lot of effort, which is a big drawback with some of the other DIY machines. As a bonus, the structural frame is quite sturdy and well suited for this purpose. The other main part of such a machine is the heated injection block and there are several different ways of doing it. After some amount of studying probable solutions, he decided to build a heated aluminium block through which the plastic granules can be rammed using the hydraulic piston. Heating is provided by a pair of 500W heaters and a type ‘k’ thermocouple does temperature sensing. An industrial PID controller adjusts the block temperature via a solid state relay. Overall, the electrical and mechanical layout cannot get any simpler.
[Bolzbrain] did a great job of documenting his build over a series of videos and more wizened hackers watching them will squirm in their seats spotting the numerous fails. He bought the cheapest pedestal drill machine that he could buy and watching the drill struggle while making a 26mm hole in the aluminium block is quite jarring.
The electrical wiring has a lot of scope for improvement – with 220V AC heaters, exposed wiring and jury rigged panel held up with a pair of clamps. Installing and removing the die is a task and requires a lot of fiddling with several C-clamps — something which needs to be repeated for every shot. Maybe toggle clamps could help him to ease die fixing and removal. Once he figures out about mold release agents and wall draft angles, he won’t have to struggle trying to remove the molded article from the die. Then there’s the issue of proper runner design so that the thermo-plastic can quickly fill the mold cavity completely without any pockets.
But in the end, all that matters is that he is getting reasonably good molded parts for his purposes. With more tweaking and incremental improvements, we’re sure he’ll get better results. The video after the break is a short overview of his build, but the project page has a series of detailed videos covering all aspects of the project. And if you’d like to get an introduction to desktop injection molding, check out “Benchtop Injection Molding for the Home Gamer”
Recently, I was offered a 1997 Volkswagen Golf for the low, low price of free — assuming I could haul it away, as it suffered from a thoroughly borked automatic transmission. Being incapable of saying no to such an opportunity, I set about trailering the poor convertible home and immediately tore into the mechanicals to see what was wrong.
Alas, I have thus far failed to resurrect the beast from Wolfsburg, but while I was wrist deep in transmission fluid, I spotted something that caught my eye. Come along for a look at the nitty-gritty of transmission manufacturing!
Continue reading “Peeking Inside A VW Gearbox Reveals Die Casting Truths”
Many people have the means now to create little plastic objects thanks to 3D printing. However, injection molding is far less common. Another uncommon tech is plastic recycling, although we do occasionally see people converting waste plastic into filament. [Manuel] wants to solve both of those problems and created an injection molder specifically for recycling.
The machine — Smart Injector — is automated thanks to an Arduino. It’s pretty complex mechanically, so in addition to CAD models there are several PDF guides and a ton of pictures showing how it all goes together.
