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.

Nearly Entirely 3D Printed RC Car Is 4WD Fun

April 9, 2019 by Lewin Day 16 Comments

Remote control cars can be great fun, particularly if you’ve got a spare carpark or dirt lot to hoon them around. Any good hobby store will have shelves stocked with all manner of vehicles – buggies, touring cars, prototypes – but you don’t have to settle for what’s already available. Why not 3D print the car of your dreams instead? (YouTube, embedded below.)

The build comes to us from [Engineering Nonsense], now in its third revision. The design is produced in PLA, to make it accessible as possible to printer owners the world over. Almost the entire car is 3D printable – not just the chassis. The gearbox, differentials and driveshafts, and even suspension arms and tie rods are all printed, rather than bought. This also means the car is easier to build, with everything being printed to the correct size, as opposed to using off-the-shelf adjustable parts.

Performance is impressive, with the car showing good grip thanks to its 4WD drivetrain and double wishbone suspension. Files are available on Thingiverse, so there’s nothing to stop you from printing this out and going for a spin this weekend. We’d love to see it take on the water with some 3D printed tyres, too.

[Thanks to Jotham for the tip!]

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Metal 3D Printing — A Dose Of Reality

April 8, 2019 by Al Williams 19 Comments

We have no doubt that hundreds of times a day a hacker is watching a 3D printer spew hot plastic and fantasizes about being able to print directly using metal. While metal printers are more common than ever, they are still out of reach for most people printing as a hobby. But as Mr. Spock once observed: “…you may find that having is not so pleasing a thing after all as wanting. It is not logical, but it is often true.” However, metal 3D printing has its own unique set of challenges. Texas A&M recently produced a short video explaining some of the design issues that you’ll encounter trying to make practical metal prints on an SLS (Selective Laser Melting) printer. You can see the video below.

The description says “It is more challenging to ‘metal 3D print’ a part than most people think. We’ve noticed the same even with plastic printers as friends will expect us to print the most outlandish things for them. What we like about this video is it helps to set expectations of the current state of the art so we’re not expecting far more than today’s metal printers can produce.

Among the features covered in the video are overhangs, which require supports. After removal, the surface is about like 80 grit sandpaper unless you perform further finishing. Just like plastic parts, warping and curling of large areas is a problem with metal. If you’ve ever been frustrated removing plastic support material, try having to ceramic grind metal supports off. They also use an EDM machine to cut especially tough supports, but it causes a lot of effort since it is likely to run through EDM wires and clog the filters.

We looked at recent advances in metal printing last year. We’ve seen homebrew machines that were little more than welders under computer control and we’ve seen plans by big players like HP to create metal prints, but at a steep price. Still, you can’t stop the march of 3D printing progress.

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The 3D Printing Dream Is Still Alive At 2019’s Midwest RepRap Festival

April 8, 2019 by Sonya Vasquez 8 Comments

3D Printers have been in the hands of hackers for well over ten years, but the dream is far from over and certainly not overslept. This year’s Midwest RepRap Festival is a testament to the still-growing excitement, and world where 3D printing is alive and kicking on the next level.

This past weekend, I took up my friend [Eric’s] advice to come down and participate firsthand, and I was simply blown away. Not only did we witness the largest number of attendees to date, MRRF 2019 spilled into not one but two conference halls at the Goshen Fairgrounds.

In what follows, I tell my tale of the times. Continue reading “The 3D Printing Dream Is Still Alive At 2019’s Midwest RepRap Festival” →