3D Printing A Real Heart

April 23, 2019 by Pedro Umbelino 12 Comments

As 3D printing becomes more and more used in a wide range of fields, medical science is not left behind. From the more standard uses such as printing medical equipment and prosthetics to more advanced uses like printing cartilages and bones, the success of 3D printing technologies in the medical field is rapidly growing.

One of the last breakthrough is the world’s first 3D vascularised engineered heart using the patient’s own cells and biological materials. Until now, scientists have only been successful in printing only simple tissues without blood vessels. Researchers from Tel Aviv University used the fatty tissue from patients to separate the cellular and acellular materials and reprogrammed the cells become pluripotent stem cells. The extracellular matrix (ECM) was processed into a personalized hydrogel that served as the basis from the print.

This heart is made from human cells and patient-specific biological materials. In our process these materials serve as the bioinks, substances made of sugars and proteins that can be used for 3D printing of complex tissue models… At this stage, our 3D heart is small, the size of a rabbit’s heart, but larger human hearts require the same technology.

After being mixed with the hydrogel, the cells were efficiently differentiated to cardiac or endothelial cells to create patient-specific, immune-compatible cardiac patches with blood vessels and, subsequently, an entire heart that completely matches the immunological, cellular, biochemical and anatomical properties of the patient. The difficulty of printing full-blown organs were being tackled for a long time and we already talked about it in the past.

The development of this technology may completely solve both the problem of organ compatibility and organ rejection.

Steel-Reinforced 3D Prints

April 22, 2019 by Brian Benchoff 17 Comments

Continuing on the never-ending adventure of how to make a 3D print stronger, [Brauns CNC] is coming at us with a new technique that involves steel-reinforced 3D printed parts.

We’ve seen plenty of methods to create stronger 3D prints, from using carbon fiber filament to simply printing the part in a way that the layers of the print are orthogonal to the direction of force. We’ve even seen casting carbon fiber bars into 3D prints, but of course that will only work with straight parts. [Brauns]’ technique uses steel wire, embedded into the print itself, and from some testing there’s about a 50% increase in strength of the part.

The process of embedding a steel cable into a 3D printed part is simply taking apart the model and putting a channel in for the cable. At a specific layer height, the printer is stopped, the steel cable is embedded with the help of a soldering iron, and the printer continues doing its thing.

There’s a slight amount of Gcode hacking to make this happen, and the process of embedding a steel cable into a print is a bit finicky. Still, if you want stronger 3D prints, there are worse ways to do it, and certainly less effective ways of doing it. You can check out the video for this technique below.

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Watch These Two Robots Cooperate On A 3D Print

April 20, 2019 by Donald Papp 16 Comments

Putting a 3D printer on a mobile robotic platform is one thing, but two robots co-cooperatively printing a large object together is even more impressive. AMBOTS posted the video on Twitter and we’ve embedded it below.

The robots sport omnidirectional wheels and SCARA format arms, and appear to interact with some kind of active tabletop to aid positioning. The AMBOTS website suggests that the same ideas could be used for other tasks such as pick and place style assembly work, and the video below of co-operative 3D printing is certainly a neat proof of concept.

As a side note: most omni wheels we see (such as the ones on these robots) are of the Mecanum design but there are other designs out there you may not have heard of, such as the Liddiard omnidirectional wheel.

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3D Printed Tank Track Pops Together With Plastic BB For Hinge

April 20, 2019 by Donald Papp 20 Comments

3D printing is well-suited to cranking out tank tread designs, because the numerous and identical segments required are a great fit for 3D printing’s strengths. The only hitch is the need for fasteners between each of those segments, but [AlwynxJones] has a clever solution that uses plentiful hard plastic spheres (in the form of 6 mm airsoft BBs) as both a fastener and a hinge between each of the 3D printed track segments.

Each segment has hollows made to snugly fit 6 mm BBs (shown as green in the image here) which serve both as fasteners and bearing surfaces. Assembly requires a bit of force to snap everything together, but [AlwynxJones] judges the result worth not having to bother with bolts, wires, or other makeshift fasteners.

Bolts or screws are one option for connecting segments, but those are heavy and can get expensive. Segments of printer filament have been successfully used in other tread designs, though that method requires added work in the form of either pins, or heat deforming the filament ends to form a kind of rivet. This design may be a work in progress, but it seems like a promising and clever approach.

[via Reddit]

Thirty Six Frets For A 3D Printed Guitar

April 19, 2019 by Brian Benchoff 5 Comments

Only 80s kids will remember actual hair metal with the meedley-mees way up high on the fret board, and in the 80s, fret boards got longer. Twenty one or twenty two frets on a guitar weren’t good enough, and you needed the full two octaves of twenty four frets. As with anything, more is better, so [Said Too Much] decided to add frets to his guitar. Yes, you can do that, and it actually doesn’t sound too bad, all things considering.

A few things to cover before going over this build. This did not start out as an experiment to extend the fretboard of a guitar. This started out as a soprano guitar build; this would be the inverse of a baritone guitar — instead of an extended scale length and heavier strings to play a fourth or fifth below a regular guitar, this soprano guitar would have a shorter scale length and lighter gauge strings to play a fourth or fifth above a regular guitar. After a few calculations and some calls to companies that make very, very thin guitar strings, this project morphed into a 3/4 scale guitar (a 23″ scale length, although I question that scale length being actually 3/4 scale) and a set of strings that used 0.07″ strings.

Since a soprano guitar is pretty much just like a normal guitar with more frets, this project also got an extended, 3D printed fretboard. Why? Because. The stock pick guard was modeled and printed out in PLA, removing the neck and middle pickups. Then, an ‘extended fret board adapter’ of sorts was slotted in behind the strings. This gives the guitar 38 frets, a full third of them being printed in PLA.

The burning question: does a 3D printed fret board work? Yes, kind of. If you can get your fingers in between the frets, you can absolutely play the 36th fret on this guitar. It’s not for everybody, obviously, and PLA printed frets will never be as good as polished metal frets. But it is an interesting experimental technique for stringed instruments we haven’t seen before. Check out the video below.

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A Mostly 3D Printed Speaker

April 17, 2019 by Lewin Day 2 Comments

The common magnetic loudspeaker is, fundamentally, a fairly simple machine. A static magnetic field is generated by a permanent magnet, and a membrane is mechanically connected to a coil. When a varying electrical current is passed through the coil, this causes the coil to move due to the magnetic field, vibrating the membrane and producing sound. [Mattosx] put this theory into practice with a simple 3D-printed speaker.

It’s not the first 3D-printed speaker we’ve ever seen, but it’s one of the cutest. The main body of the speaker is rectangular, and has a cavity in which three neodymium magnets are placed. The vibrating membrane is then printed separately, including an integrated spindle upon which the coil is wound. The assembly is held together with some socket-head cap screws which complement the pleasantly modern look.

The device does a good job delivering the bleeps when hooked up to an Arduino, and we could see this basic design serving well in all manner of charming 3D-printed builds. Video after the break.

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Custom Rotary Switch Takes A Motor

April 10, 2019 by Al Williams 9 Comments

There are certain challenges we all will have to face sooner or later. Changing a flat tire in the rain, trying to put on a shirt that doesn’t quite fit, or producing a 16 position rotary switch for a replica computer front panel. There was a time when something like this would be a major undertaking, but with the help of a 3D printer [Mike Gardi] was able to build good looking switches that were big enough to be motor driven.

Switches of course are old tech, and there are plenty of ways to make contacts. [Mike] settled on using 16 small magnets and reed switches. This works, but you probably wouldn’t want to use it where the switch might get close to an external magnet. It does however make for a neat assembly without a lot of mechanical work. It also resists wear compared to a brush type arrangement.

The switch is a little large, but it could probably be made smaller with proper contacts. However, you still need at least some magnets to provide the detents without making mechanical changes.

We couldn’t help but think of the homemade rotary switches from the do it yourself computer that used sewing thread spools, wires, and paper clips. It would be fun to revisit that computer with an eye to making things using a 3D printer. We liked the knob, but if you only need a reproduction knob, there are other ways to go.