Traditional desktop 3D printing technology has effectively hit a wall. The line between a $200 and a $1000 printer is blurrier now than ever before, and there’s a fairly prevalent argument in the community that you’d be better off upgrading two cheap printers and pocketing the change than buying a single high-end printer if the final results are going to be so similar.
As anyone who’s pushed their 3D printer a bit too hard can tell you, the first thing that usually happens is the extruder begins to slip and grind the filament down. As the filament is ground down it starts depositing plastic on the hobbed gear, further reducing grip in the extruder and ultimately leading to under-extrusion or a complete print failure. To address this issue, MIT’s printer completely does away with the “pinch wheel” extruder design and replaces it with a screw mechanism that pulls special threaded filament down into the hot end. The vastly increased surface area between the filament and the extruder allows for much higher extrusion pressure.
An improved extruder doesn’t do any good if you can’t melt the incoming plastic fast enough to keep up with it, and to that end MIT has pulled out the really big guns. Between the extruder and traditional heater block, the filament passes through a gold-lined optical cavity where it is blasted with a pulse modulated 50 W laser. By closely matching the laser wavelength to the optical properties of the plastic, the beam is able to penetrate the filament and evenly bring it up to nearly the melting point. All without physically touching the filament and incurring frictional losses.
There are still technical challenges to face, but this research may well represent the shape of things to come for high-end printers. In other words, don’t expect a drop-in laser hot end replacement for your $200 printer anytime soon; the line is about to get blurry again.
Charcuterie is delicious — but is it hackable? When talking about the salty preserved meats, one might be more inclined to indulge in the concept of bacon before pondering a way to integrate an electrical monitoring system into the process. However, [Danzetto] decided to do both when he did not have anywhere to cure his meats. He made his own fully automatic meat curing chamber lovingly called the curebOS with the aid of a raspberry pi. It is basically a beefed up mini fridge with all of the bells and whistles.
This baby has everything. Sitting on top is a control system containing the Pi. There are 5 relays used for the lights, circulating fan, ventilating fans, refrigerator, and humidifier all powered by a 5 amp supply — minus the fridge. Down below that is the 3D printed cover with a damper for one of the many ventilation fans that regulate the internal temperature. To the right is a touchscreen for viewing and potentially controlling the system if necessary. The control program was written in Python for viewing the different trends. And below that, of course, is a viewing window. On the inside are temperature and humidity probes that can be monitored from the front screen. These readings help determine when to activate the compressor, any of the fans, or the humidifier for optimal settings. For a final touch, there are also some LEDs placed above the hanging meat to cast a glowing effect upon the prized possessions.
It all started months ago, when [Matt] built his original Giant Lego Go-Kart, a 5-times scaled up model of the original kit #1972-1. Achieved through the wonder of 3D printing, he had sized it up based off the largest parts he could fit on his printer. The Youtube video led to commenters asking – could it be driven?
He decided that radio control was definitely a possibility. Not content to simply bolt on a series of motors to control the drive and steering, he took the effort to build scaled up replica LEGO motors, even taking care to emulate the old-school connectors as well. A particularly nice touch was the LEGO antenna, concealing the Orange RX radio receiver.
There were some hiccups – at this scale & with [Matt]’s parts, the LEGO force just isn’t strong enough to hold everything together. With a handful of zipties and a few squirts of glue, however, the giant ‘kart was drifting around the carpark with ease and hitting up to 26km/h.
In the end, the build is impressive not just for its performance but the attention to detail in faithfully recreating the LEGO aesthetic. As for the next step, we’d like to know what you think – how could this be scaled up to take a human driver? Is it possible? You decide.
Recently, a YouTube video has been making the rounds online which shows a rather astounding comparison between two printed models of the US Capitol. Starting with the line “3-D PRINTERS CAN NOW PRINT TWICE AS FAST”, the video shows that one print took four hours to complete, and the other finished in just two hours by virtue of vibration reducing algorithms developed at the University of Michigan. The excitement around this video is understandable; one of the biggest limitations of current 3D printer technology is how long it takes to produce a model of acceptable quality, and if improvements to the software that drives these machines could cut total print time in half, the ramifications would be immense.
The mechanical and electronic parts of a 3D printer are critical for success, but so is the slicing software. Slic3r and Cura are arguably the most popular, and how they command your printer has a lot to do with the results you can get. There are lots of other slicers out there both free and paid, but it is hard to really dig into each one of them to see if they are really better than whatever you are using today. If you are interested in the performance of IceSL — a free slicer for Windows and Linux — [DIY3DTECH] has a video review that can help you decide if you want to try it. You can see the video below.
IceSL has several modules and can actually do OpenSCAD-like modeling in Lua so you could — in theory — do everything in this one tool. The review, though, focuses only on the slicing aspect. In addition to the desktop client versions, you can use some features online (although on our Linux machine it didn’t work with the latest Chrome beta even with no add ons; Firefox worked great, though).
Shoes are some of the most complex pieces of equipment you can buy. There’s multiple materials ranging from foam to weird polyesters in a simple sneaker, and if you dig into shoes for biking, you’ll find some carbon fiber. All these layers are glued together, stitched, and assembled into a functional piece of exercise equipment, with multiple SKUs for each size. It’s really amazing.
Accordingly, [marcs] created N+ Open Bike Shoe Platform, the purpose of which is to create open source, customizable, and repairable shoe platform based on 3D printing, though with other techniques like rubber molding and sewing fabric uppers are included as well.
The project breaks down its signature shoe into all its various parts: heel, toe tread, insole, upper, and so on. With each part individually customizable, the shoe can be tailored to suit each individual, all while part of a cradle-to-grave lifecycle that allows shoe parts to be replaced, repaired, or recycled.
[Tommy] shares a simple 3D printing design tip that will be self-evident to some, but a bit of a revelation to others: the concept of a sacrificial bridge to avoid awkward support structures. In the picture shown, the black 3D print has small bridges and each bridge has a hole. The purpose of these bits is to hold a hex nut captive in the area under the bridge; a bolt goes in through the round hole in the top.
Readers familiar with 3D printing will see right away that printing the bridges might be a problem. When a printer gets to the first layer of the bridge, it will be trying to lay filament in empty space. By itself this is not usually a problem as long as a bridge is short, flat, and featureless. Unfortunately this bridge has a hole in it, and that hole means the printer will be trying to draw circles in mid-air, rather than simply stretching filament point-to-point across a gap. One solution would be to add a small amount of support structure, but that just moves the problem. Removing small supports from enclosed spaces can be a real hassle.
To solve this [Tommy] added what he calls a “sacrificial bridge”, shown as blue in the CAD image. He essentially gives the hole a flat bottom, so that the printer first lays down a thin but solid bridge as a foundation. Then, the portion with the round hole is printed on top of that. With this small design change, the print becomes much more reliable with no support structure required.
There is a bit of post-work involved since each hole needs to be drilled out to punch through the thin sacrificial bridge underneath, but it definitely beats digging out little bits of support structure instead.