Liquid (Reversibly) Solidifies At Room Temperature, Gets Used For 3D Prints

August 9, 2024 by Donald Papp 8 Comments

Researchers demonstrate sustainable 3D printing by using poly(N-isopropylacrylamide) solutions (PNIPAM), which speedily and reliably turn solid by undergoing a rapid phase change when in a salt solution.

This property has been used to 3D print objects by using a syringe tip as if it were a nozzle in a filament-based printer. As long as the liquid is being printed into contact with a salt solution, the result is a polymer that solidifies upon leaving the syringe.

What’s also interesting is that the process by which the PNIPAM-based solutions solidify is entirely reversible. Researchers demonstrate printing, breaking down, then re-printing, which is an awfully neat trick. Finally, by mixing different additives in with PNIPAM, one can obtain different properties in the final product. For example, researchers demonstrate making conductive prints by adding carbon nanotubes.

While we’ve seen the concept of printing with liquids by extruding them into a gel bath or similar approach, we haven’t seen a process that prides itself on being so reversible before. The research paper with all the details is available here, so check it out for all the details.

Need Many Thin Parts? Try Multi-material Stack Printing

July 27, 2024 by Elliot Williams 9 Comments

Admittedly it’s a bit of a niche application, but if you need lots of flat 3D printed objects, one way to go about it is to print them in a stack and separate them somehow. An old(er) solution is to use a non-extruding “ironing” step between each layer, which makes them easier to pull apart. But another trick is to use the fact that PLA and PETG don’t stick well to each other to your advantage. And thus is born multi-material stack printing. (Video, embedded below the break.)

[Jonathan] wants to print out multiples of his fun Multiboard mounting system backplates, and these are the ideal candidate for stack printing: they’re thin, but otherwise take up the entire build plate. As you’d expect, the main trick is to print thin layers of PETG between the PLA plate layers that you do want. He demonstrates that you can then simply pull them apart.

There are some tricks, though. First is to make two pillars in addition to the plates, which apparently convinces the slicer to not flatten all the layers together. (We don’t really understand why, honestly, but we don’t use Bambu slicer for multi-materials.) The other trick that we expect to be more widely applicable, is that [Jonathan] extrudes the PETG interlayers a little thicker than normally. Because the PETG overflows the lower PLA layer, it physically locks on even though it chemically doesn’t. This probably requires some experimentation.

As multi-material printers get cheaper, we’ve seen a lot more innovative uses for them popping up. And we wouldn’t be so stoked about the topic if there weren’t a variety of hacker projects to make it possible. Most recently, the impressive system from [Armored_Turtle] has caught our eye. Who knows what kind of crazy applications we’ll see in the future? Are you doing multi-material yet?

Continue reading “Need Many Thin Parts? Try Multi-material Stack Printing” →

A 3D-printed puzzle for the visually impaired. The pieces have both a texture and a slant.

A Puzzle For The Visually Impaired, Or Blindfolded

July 24, 2024 by Kristina Panos 8 Comments

There’s no reason why a visually impaired person can’t enjoy putting together a jigsaw puzzle. It just needs to look a little different. Or, in this case, feel different.

16-year-old [feazellecw] has come up with just the solution — a puzzle with pieces that have both a defining texture and a slant in the z-height to them. While there is no picture on the puzzle face to speak of, instead there is a satisfying end result. You could change it up and add a relief image if you wanted, as long as you still observed the diagonal lines, the z-slant, and the little hole in the bottom that helps differentiate it from the top.

As [feazellecw] says, it’s important to find a box to help keep the pieces together during assembly; a 3D-printed box would be a nice touch. Files for this 15-piece puzzle are available if you’d like to make one for yourself or someone else, but just the idea might inspire you to make your own variant.

Don’t like putting puzzles together? Build a robot to do it for you.

CeraMetal Lets You Print Metal, Cheaply And Easily

July 21, 2024 by Elliot Williams 27 Comments

3D printing metal has been somewhat of a holy grail for the last decade in the hobby 3DP scene. We’ve seen a number of solutions, including using expensive filaments that incorporate metal into the usual plastic. In parallel, we’ve seen ceramic printers, and paste printers in general, coming into their own. What if you combined the two?

You’d get [Leah Buechly] et al’s CeraMetal process, which is the cheapest and most straightforward metal printing method we’ve seen to date. It all starts off with a custom bronze metal clay, made up of 100 g bronze powder, 0.17 g methyl cellulose, 0.33 g xanthan gum, and 9 g water. The water is fine-tuned to get the right consistency, and then it’s extruded and sintered.

The printer in question is an off-the-shelf ceramic printer that appears to use a pressurized clay feed into an auger, and prints on a linen bed. [Leah] had to write a custom slicer firmware that essentially runs in vase mode but incorporates infill as well, because the stop-start of normal slicers wreaked havoc with clay printing.

The part is then buried in activated carbon for support, and fired in a kiln. The result is a 3D printed bronze part on the cheap; the material cost is essentially just the cost of the metal powder and your effort.

We had never heard of metal clay before, but apparently jewelers have been using it for metals other than just bronze. The Metal Clay Academy, from the references section of the paper, is an amazing resource if you want to recreate this at home.

Paste printers are sounding more and more interesting. Obvious applications include printing chocolate and printing pancakes, but now that we’re talking metal parts with reasonably consistent shrinkage, they’ve got our attention.

Sharing 3D Printing With Kids

July 15, 2024 by Al Williams 16 Comments

If you have a hobby, it is natural to want to share it with kids. If you are interested in 3D printing, you may even have kids who want to try their hand at printing without prompting. There are a number of “kid printers” aimed specifically at that market. Are they worthwhile? How old is old enough? [Everson Siqueirar] tries out a Kidoodle with this 6-year-old daughter, and the results are good, as you can see in the video below.

Impressively, his daughter [Sophie] was able to set up the printer with a little help. The build plate is very small and not heated. Apparently, a glue stick is necessary for bed adhesion. The printer has WiFi but also has a collection of models you can print without any internet connection.

Continue reading “Sharing 3D Printing With Kids” →

If You Want An Expensive Chair Just Print Your Own

July 10, 2024 by Lewin Day 20 Comments

The Magis Spun chair is a weird piece. It’s basically a kind of seat with a round conical base that stops it from sitting still in one place. Instead, it rolls and pivots around when you sit on it, which is apparently quite fun. They’re expensive though, which gave [Morley Kert] a neat idea. Why not 3D print one instead?

Obviously 3D printing a sofa wouldn’t be straightforward, but the Magis Spun is pretty much just a hunk of plastic anyway. The real thing is made with rotational molding. [Morley] suspected he could make one for less than the retail price with 3D printing.

With no leads on a big printer, he decided to go with a segmented design. He whipped up his basic 3D model through screenshots from the manufacturer’s website and measurements of a display model in a store. After print farming the production, the assembly task was the next big challenge. If you’re interested in doing big prints with small printers, this video is a great way to explore the perils of this idea.

Ultimately, if you want to print one of these yourself, it’s a big undertaking. It took 30-50 print days, or around 5 days spread across 15 printers at Slant 3D’s print farm. It used around $300-400 of material at retail prices, plus some extra for the epoxy and foam used to assemble it.

The finished product was killer, though, even if it looks a little rough around the edges. It rolls and pivots just like the real thing.

We don’t feature a lot of chair hacks on Hackaday, but we do feature some! Video after the break.

Continue reading “If You Want An Expensive Chair Just Print Your Own” →

A small 3D-printed printing press with a print that says THE QUICK BROWN FOX JUMPED OVER THE LAZY BROWN DOG.

Mini 3D-Printed Press Is Sure To Make An Impression

July 4, 2024 by Kristina Panos 9 Comments

Making stamps out of potatoes that have been cut in half is always a fun activity with the kids. But if you’ve got a 3D printer, you could really step up your printing game by building a mini relief printing press.

To create the gear bed/rack, [Kevr102] used a Fusion 360 add-in called GF Gear Generator. At first this was the most finicky part of the process, but then it was time to design the roller gears. However, [Kevr102] got through it with some clever thinking and a little bit of good, old-fashioned eyeballing.

Per [Kevr102], this press is aimed at the younger generation of printers in that the roller mechanism is spring-loaded to avoid pinched fingers. [Kevr102] 3D-printed some of the printing tablets, which is a cool idea. Unfortunately it doesn’t work that well for some styles of text, but most things came out looking great. You could always use a regular linocut linoleum tile, too.

This isn’t the first 3D-printed printing press to grace these pages. Here’s one that works like a giant rubber stamp.