While packing merch for a recent gig, I realised I had the opportunity to do something a little fun. I’d released an album on tape, and spent a little extra to ensure the cassette itself was a thing of beauty. It deserved to be seen, rather than hidden away in a case on a shelf. I wanted to turn this piece of musical media into a necklace.
Of course, cassette tapes aren’t meant to be used in this way. Simply throwing a chain through the cassette would lead to tape reeling out everywhere. Thus, I fired up some CAD software and engineered a solution to do the job! Here’s how I built an adapter to turn any cassette tape into a cool necklace.
The first part to build is the egg-hat-stand. This consists of the base of the structure, with the “hat” of the egg character hanging in the center. The other half of the structure is built separately, with the rest of the “egg head” sitting in a cup in the bottom of the upper structure. A series of nylon threads are then tied between the components. These can then be tensioned to give the structure its shape, allowing the egg’s “hat” to hover above its “head”. [seabirdhh] passes the nylon threads through small pieces of rubber that allow the tension to be adjusted just right. Too little and the structure falls down, but too much, and it will bend over time. Tuning it carefully is key.
3D printing is known for producing parts with a fairly average finish at best. Even the smoothest resin prints are still fairly plasticky and dull in appearance. However, it’s possible to do much better if you get creative with electroplating. This thermal detonator prop from [HEN3DRIK] shows just how good a 3D print can look with a little post-processing and some chemical help.
[HEN3DRIK] started with a Star Wars thermal detonator model found online, and printed it in resin for the best possible surface finish from the get go. The parts were cleaned after printing and cured, as per usual resin processing techniques. From there, fine steel wool and sandpaper was used to make the print as smooth as possible. A conductive layer of copper paint was then sprayed on with an airbrush, with mating surfaces masked off to avoid ruining the fit.
The part was then dunked in an acidic copper bath while attached to a power source, and gently rotated during the electroplating process. The results were excellent, resulting in near-mirror finish copper-plated parts after polishing. Nickel was then plated on top to get the prop to the proper silver color. The prop was finally then assembled with an Arduino Nano inside to run several LEDs for visual effect.
Toner transfer is a commonly-used technique for applying text and images to flat surfaces such as PCBs, but anybody who has considered using the same method on 3D prints will have realized that the heat from the iron would be a problem. [Coverton] has a solution that literally turns the concept on its head, by 3D printing directly onto the transparency sheet.
The fine detail is great for intuitive front-panel designs
The method is remarkably straightforward, and could represent a game-changer for hobbyists trying to achieve professional-looking full-color images on their prints.
First, the mirrored image is printed onto a piece of transparency film with a laser printer. Then, once the 3D printer has laid down the first layer of the object, you align the transparency over it and tape it down so it doesn’t move around. The plastic that’s been deposited already is then removed, and a little water is placed on the center of the bed. Using a paper towel, the transparency gets smoothed out until the bubbles are pushed off to the edges.
Another few pieces of tape hold the transparency down on all corners, and the hotend height is adjusted to take into account the transparency thickness. From there, the print can continue on as normal. When finished, the image should be fused with the plastic. If it’s hard to visualize, check out the video after the break for a step-by-step guide.
There are, of course, some caveats. Aligning the transfer and the print looks a little fiddly at the moment, the transparency material used (obviously) has to be rated for use in laser printers, and it only works on flat surfaces. But on the other hand, there will be some readers who already have everything they need to try this out at home right now — and we’d love to see the results!
We’ve covered some other ways to get color and images onto 3D prints in the past, such as this hydrographic technique or by using an inkjet printhead, but [Coverton]’s idea looks much simpler than either of those. If you’re interested in toner transfer for less heat-sensitive materials, then check out this guide from a few years back, or see what other Hackaday readers have been doing on wood or brass.
Overhangs are the bane of the melty-plastic 3D printing world. Often, we try to avoid them with creative print alignments, or we compensate with supports. However, [3DPrintBunny] decided to embrace overhangs in the extreme in the design of her creative 3D-printed string vase.
The design is intended to be printed with a larger nozzle, on the order of 0.8 mm or so, at a layer height of 0.6 mm. Under these conditions, the printer nozzle bridges the gap between the vase’s pillars with a single string of molten filament. With the settings just so, the molten filament stays attached during the bridging operation, and creates a fine plastic string between the pillars. Repeat this across the whole design, and you get an attractive string vase.
Amazingly, [3DPrintBunny] didn’t have to do any fancy slicer tricks to achieve this. Stock slicer settings got the job done just fine, and she reports that the model should print on most FDM printers. For her own examples, she printed in a special silver/bronze dual color PLA filament.
One of the issues with 3D printing is that when a print is done, you need to go back and pull the print off the bed to reset it for the next one. What if you needed to print 600 little parts for whatever reason? Most people might say get lots of printers and queue them up. Not [Pierre Trappe], as he decided that his Prusa i3 MK3S+ would print continuously.
The setup was dubbed Loop and consisted of a few parts. First, there’s an arm that sweeps the build plate to clear the printed pieces, a slide for the pieces to descend on, and a stand for the printer to sit on that puts it at an angle. The next step is to modify OctoPrint to allow a continuous print queue. The slicer needs to change as [Pierre] provides some G-code to reset the printer and clear the print.
We were especially impressed with the attention to detail in the documentation for this one. There’s extensive guidance on getting the bed adhesion just right, as you can’t have it come off mid-print, but you need it to detach cleanly and easily when the arm sweeps across the bed. Calibrating that first layer is essential, and he provides handy instructions to dial it in. Additionally, temperature and material play a crucial role, and [Pierre] documented the different materials and temperatures he used while developing Loop.
While continuous belt printers are arguably the “correct” answer to the question of printing 600 little parts, they come with their own baggage. Being able to pull off something similar on a printer as reliable and well supported as the Prusa i3 makes for a compelling alternative.
Debra Ansell of [GeekMomProjects] fame came up with a neat, 3D design that prints flat and then folds up into everyone’s favorite Platonic solid: a D12.
Why would you want to do this? Well, folding up your 3D prints gives you a third dimension “for free” without using all that support material. Here, all of the outside faces of the dodecahedron are printed flat against the build plate, which is probably the nicest side of your prints. And embedding LEDs in the resulting shape would probably be easy because they’re all in plane. And speaking of LEDs, we kinda expected to see them here, given Debra’s motto: “LEDs improve everything” — that part is up to you.
Debra notes that she likes PETG instead of PLA for the extra strength in the thin-printed hinges, and we’d bet that your printer’s tolerances will need to be spot on for the clips that hold the whole thing together. (We’d be tempted to apply a little super-duper glue.)
As always with Debra’s projects, there’s some creative solutions on display here that’ll help you out whether you need a D12 or a D20, so give it a look!
