3d printed

634 Articles

The Evolution Of A 3D Printed Off-Road R/C Car

April 9, 2020 by 13 Comments

For about as long as hackers and makers have been using desktop 3D printers, there have been critics that say the plastic parts they produce aren’t good for much else than toys and decorative pieces. They claim that printed parts are far too fragile to be of any practical use, and are better suited as prototype placeholders until the real parts can be injection molded or milled. Sure. Try telling that to [Engineering Nonsense].

He recently wrote in (as did a few other people, incidentally) to share the latest version of his incredible 3D printed remote control car, and seeing it tearing around in the video after the break, “fragile” certainly isn’t a word we’d use to describe it. Though it didn’t get that way overnight. The Tarmo4 represents a year of development, and as the name suggests, is the fourth version of the design.

We know the purists out there will complain that the car isn’t entirely 3D printed, but honestly, it’s hard to imagine you could get much closer than this. Outside of the electronics, fasteners, tires, and shocks, the Tarmo4 is all plastic. That includes the gearbox and drive shafts. [Engineering Nonsense] even mentions in the video that he’s not happy with the tires he’s found on the market, and that they too will likely get replaced with printed versions in the future.

While the car is certainly an incredible technical achievement, what’s perhaps just as impressive is the community that’s developed around it in such a relatively short time. Towards the end of the video he shows off a number of custom builds based on previous iterations of the Tarmo. We’re sure that interest from the community has played a part in pushing the design forward, and it’s always good to see a one-off project become something bigger. Hopefully we’ll be seeing even more from this passionate community in the near future.

Just like the Open R/C Project, Tarmo proves that 3D printed parts are more than a novelty. If these diminutive powerhouses can run with printed gears and drive shafts, then you shouldn’t have anything to worry about when you run off the parts for your next project.

Continue reading “The Evolution Of A 3D Printed Off-Road R/C Car” →

The CLUE Tracker Points You To A Target, Using CircuitPython

April 5, 2020 by 2 Comments
The main components are an Adafruit CLUE, Stemma GPS, and a lithium-polymer battery. No soldering required.

[Jay Doscher] shares a quick GPS project he designed and completed over a weekend. The device is called the CLUE Tracker and has simple goals: it shows a user their current location, but also provides a compass heading and distance to a target point. The idea is a little like geocaching, in that a user is pointed to a destination but must find their own way there. There’s a 3D printed enclosure, and as a bonus, there is no soldering required.

The CLUE Tracker uses the Adafruit CLUE board (which is the same size as the BBC micro:bit) and Stemma GPS sensor, with the only other active component being a lithium polymer battery. The software side of the CLUE Tracker uses CircuitPython, and [Jay] has the code and enclosure design available on GitHub.

[Jay] did a nice job of commenting and documenting the code, so this could make a great introductory CircuitPython project. No soldering is required, which makes it a little easier to re-use the parts in other projects later. This helps to offset costs for hackers on a budget.

The fact that a device like this can be an afternoon or weekend project is a testament to the fact that times have never been better for hobbyists when it comes to hardware. CircuitPython is also a fast-growing tool, and projects like this can help make it easy and fun to get started.

Autonomous 3D Rover With Tank Tracks Rules The Fields. Almost

April 2, 2020 by 1 Comment

Scope creep is a real pain in the real world, but for projects of passion it can have some interesting consequences. [rctestflight] was playing around with 3D printed rover gearboxes, which morphed into a 3D printed tank build.

[rctestflight]’s previous autonomous rover project had problems with the cheap geared motors, and he started experimenting with his own gearbox designs to use with lower RPM / Kv brushless drone motors. The tank came about because he wanted a simple vehicle to test his design. “Simple” went out the window pretty quickly and the final product was completely 3D printed except for the fasteners, axles, bearings, and electronics.

The tracks and gears are noisy, but it works quite well. On outdoor tests [rctestflight] did find that the tracks were prone to hooking on vines and branches, which in one case caused it to throw a track after the aluminium shaft bent. An Ardurover navigation system was added and with a 32 Ah battery was able to run autonomously for an entire day and there was surprisingly little wear on 3D printed gearbox and tracks afterward. All the STL files are up on Thingiverse, but [rctestflight] recommends waiting for an upcoming update because he discovered flaws in the design after filming the video after the break.

For a slightly more complex and expensive rover, check out our coverage of Perseverance, NASA’s MARS 2020 Rover. Continue reading “Autonomous 3D Rover With Tank Tracks Rules The Fields. Almost” →

Fail Of The Week: In CAD, Remember To Model The Environment

March 31, 2020 by 51 Comments

What’s wrong with the above picture? Failure can be an excellent teacher, and [J. Peterson] reminds us all of this when he says to remember to model the environment when designing things in CAD. He contrasts a failure with a success to demonstrate what that means.

The failure was a stand for a screwdriver set, shown above. He modeled up a simple stand to hold a screwdriver handle and the bits in a nice, tight formation. He didn’t model any of parts, he just took some measurements and designed the holder. Everything fit just fine, but it had a major ergonomic problem: you can barely reach the handle because it is fenced in by the surrounding bits! Had he modeled all of the parts during the design phase, and not just the part he was making, this problem would have been immediately obvious during the design phase.

The contrasting success is an adapter he designed to mount an artistic glass marble to a lit display stand. The stand itself as well as the glass marble were modeled in CAD, then the adapter designed afterwards to fit them. With all of the involved objects modeled, he could be certain of how everything fit together and it worked the first time.

Now, to most people with a 3D printer of their own, discovering a part isn’t quite right is not a big (nor even a particularly expensive) problem to have, but that’s not the point. Waste and rework should be avoided if possible. To help do that, it can be good to remember to model the whole environment, not just the thing being made. Add it on to the pile of great design advice we’ve seen for designing things like enclosures and interfaces.

AvoRipe Takes A Firm Grip On The Ultimate First World Food Problem

March 18, 2020 by 14 Comments

You don’t have to be an extinct mammal or a Millennial to enjoy the smooth, buttery taste of an avocado. Being psychic on the other hand is definitely an advantage to catch that small, perfect window between raw and rotten of this divaesque fruit. But don’t worry, as modern problems require modern solutions, [Eden Bar-Tov] and [Elad Goldberg] built the AvoRipe, a device to notify you when your next avocado has reached that window.

Taking both the firmness and color of an avocado as indicators of its ripeness into account, the team built a dome holding a TCS3200 color sensor as stand for the avocado itself, and 3D printed a servo-controlled gripper with a force sensor attached to it. Closing the gripper’s arms step by step and reading the force sensor’s value will determine the softness the avocado has reached. Using an ESP8266 as centerpiece, the AvoRipe is turned into a full-blown IoT device, reporting the sensor readings to a smartphone app, and collecting the avocado’s data history on an Adafruit.IO dashboard.

There is unfortunately one big drawback: to calibrate the sensors, a set of nicely, ripe avocados are required, turning the device into somewhat of a chicken and egg situation. Nevertheless, it’s a nice showcase of tying together different platforms available for widescale hobbyist projects. Sure, it doesn’t hurt to know how to do each part from scratch on your own, but on the other hand, why not use the shortcuts that are at our disposal to remove some obstacles — which sometimes might include programming itself.

Continue reading “AvoRipe Takes A Firm Grip On The Ultimate First World Food Problem” →

Used Soda Stream Cylinder Becomes DIY Canned Air

March 17, 2020 by 16 Comments

Soda Stream machines use a cylinder of compressed CO2 to carbonate beverages, and cylinders that are “empty” for the machine’s purposes in fact still have a small amount of gas left in them. User [Graldur] shared a clever design for using up those last gasps from a cylinder by turning it into a makeshift compressed air gun, the kind that can blow crumbs or dust out of inconvenient spots like the inside of a keyboard. It’s 3D printed in PETG with a single seal printed in Ninjaflex.

[Graldur]’s 3D printed assembly screws onto the top of an “empty” cylinder and when the bottom ring is depressed like a trigger, the valve is opened slightly and the escaping gas is diverted through a narrow hole in the front. As a result, it can be used just as you would a can of compressed air. The gas outlet even accommodates the narrow plastic tubes from WD-40 cans (or disposable compressed air cans, for that matter) if more precision is required.

The design is intended for use with nearly-empty cylinders, but even so, [Graldur] also points out that it has been designed such that it can never fully actuate the cylinder’s release valve no matter how hard one presses, so don’t modify things carelessly. We also notice the design keeps the user’s hand and fingers well away from the business end of things.

This device also reminds of somewhat of a past experiment which used 3D printing to create serviceable (albeit low pressure) 3D printed compressed air tanks in custom shapes.

3D Printed Swirl Rocket Injector Turns Up The Heat

March 11, 2020 by 14 Comments

Conceptually speaking, a liquid propellant rocket engine is actually a very simple piece of hardware. All you need to do is spray your fuel and oxidizer into the combustion chamber at the proper ratio, add a spark, and with a carefully designed nozzle you’re off to the races. Or the Moon, as the case may be. It’s just that doing it in the real-world and keeping the whole thing from exploding for long enough to do some useful work is another story entirely.

Taking the process one step at a time, [Luke Walters] has been working on a 3D printed injector that tackles the first half of the problem. After nearly a dozen different prototypes, he’s come up with a printable injector design that atomizes the fuel and combines it with pressurized air at a suitable ratio for combustion. As you can see in the video at the break, it’s certainly capable of generating some impressive fireballs.

A cloud of highly atomized alcohol from the injector.

The internal passages of the injector have been designed in such a way that fuel (91% isopropyl alcohol) and air are spinning in opposite directions when they meet. This promotes more complete mixing, which in turn leads to a more efficient burn. Originally developed in the 1930s, so-called “swirl injectors” of this type were one of the key technological advancements made by Germany’s V-2 rocket program. Some ideas never go out of style.

Since the injector only touches the fuel and air prior to ignition, it doesn’t need to be particularly heat resistant. To be on the safe side [Luke] has printed the part in PETG at 100% infill, but in reality the flame front is far enough away that temperature isn’t much of a concern. That said, he does hope to eventually fit these injectors into some kind of combustion chamber, which is where things will start getting toasty.

To be clear this is not a rocket engine, and it produces no appreciable thrust. Turning a big flame into a useful means of propulsion is where things get tricky, almost as though it’s rocket science or something. But that doesn’t mean it can’t be done by suitably ambitious hackers.

Continue reading “3D Printed Swirl Rocket Injector Turns Up The Heat” →