Experimenting With 3D Printed Rocket Nozzles

Rocketry is an exacting science, involving a wide variety of disciplines, encompassing everything from fluid mechanics to thermodynamics and materials engineering. As complex as it sounds, that doesn’t mean it’s beyond the purview of the average maker. [Sciencish] demonstrates this with a series of experiments on rocket nozzles in the home lab. (Video, embedded below.)

The video starts with an amusing analogy about nozzle design based on people fleeing a bad pizza. From there, [Sciencish] 3D prints a wide variety of nozzle designs for testing. The traditional bell nozzle is there, of course, along with the familiar toroidal and linear aerospikes and an expansion deflection design. Of course, 3D printing makes it easy to try out fun, oddball geometries, so there’s also a cowbell nozzle , along with the fancy looking square and triangular aerospikes too. Testing involves running the nozzles on a test stand instrumented with a load cell. A soda bottle is filled with rubbing alcohol vapour, and the mixture is ignited, with each nozzle graded on its thrust output. The rockets are later flown outside, reaching heights over 40 feet.

[Sciencish] notes that the results are a rough guide only, as the fuel/air mixture was poorly controlled. Despite this, it’s a great look at nozzle design and all the science involved. It also wouldn’t be too hard to introduce a little more rigour and get more accurate data, either. However, if solid fuels are more your jam, consider brewing up some rocket candy instead.

Continue reading “Experimenting With 3D Printed Rocket Nozzles”

Photorender Your 3D Models

Of course, you’ll want to take your latest 3D design and print it so you’ll have a physical object. But in some cases, you’d like to have a rendering of it. If you use OpenSCAD, FreeCAD, or most other CAD programs you can get a simple rendering of your object, but what if you want something that looks real? [Teaching Tech] shows how you can use a website, Vectary, to get realistic photo renderings of your 3D models. (Video, embedded below.) The free plan has a few limits, but nothing that should bother most people.

Vectary is sort of like a super version of TinkerCad with a lot of options for realistic modeling and augmented reality. Some of the more advanced features are behind a subscription plan, but for what [Teaching Tech] is showing, you can use the free plan.

Continue reading “Photorender Your 3D Models”

Motorcycle Needs Custom Latching Switches For Turn Signals

While modern cars have been getting all kinds of fancy features like touch screens, Bluetooth, crumple zones, and steering wheel controls, plenty of motorcycles have remained firmly in the past. Some might have extra options like a fuel gauge or even ABS if you’re willing to spend extra, but a good percentage of them have the bare minimum equipment required by law. That equipment is outdated and ripe for some improvements too, like this ergonomic custom turn signal switch built with custom latching switches.

Since motorcycle turn signals don’t self-cancel like car signals the rider has to cancel it themselves, usually by pushing an inconveniently tiny button. This assembly consists of four separate switches, two of which control the left and right turn signals. Since both can’t be on at the same time, they include circuitry that can detect their position and a small motor that can physically de-latch them if the other one is pressed. The entire assembly is 3D printed, including the latching mechanism, and they are tied together with a small microcontroller for the controls.

The truly impressive part of this build is the miniaturization, since all four buttons have to be reached with the thumb without removing the hand from the handlebar. The tiny circuitry and mechanical cam for latching are impressive and worth watching the video for. And, if you need more ergonomic improvements for your motorcycle there are also some options for cruise control as well, another feature often lacking in motorcycles.

Continue reading “Motorcycle Needs Custom Latching Switches For Turn Signals”

A Different Kind Of 3D Printer: Desktop Holograms

Holograms aren’t new, but a desktop machine that spits them out could be available soon, presuming LitiHolo’s Kickstarter pans out. The machine will have a $1600 retail price and fits in a two-foot square. It can generate 4×5 inch holograms with 1mm hogels (the holo equivalent of a pixel).

The machine allows for 23 view zones per hogel and can create moving holograms with a few seconds of motion — like the famous kiss-blowing holograms.

Continue reading “A Different Kind Of 3D Printer: Desktop Holograms”

3D Printer Air Compressor Is A Wankel

We wonder if mechanics are as annoyed when we say “engine” as we get when someone talks about a “computer” or a “radio.” Sure, you know what all three of those words mean, but there are many different kinds of radios, computers, and engines. In [3DprintedLife’s] case, he made a compressed air engine of the Wankel style.

The Wankel — a rotary engine — is most famous for its use in some Mazda cars. If you’ve done a lot of 3D printing, you know that creating an air-tight piston on a 3D printer is no mean feat. Of course, he didn’t do it right off the bat. It took what looks like a number of iterations to get it going, and he shares some of what he learned doing this project.

Continue reading “3D Printer Air Compressor Is A Wankel”

3D Printed Lenticular Lens Makes 3D Display

[Bitluni] has been experimenting with resin printing lenses — in particular, lenticular lenses. You’ve probably seen lenticular lenses before in 3D greeting cards or children’s books. By presenting a slightly different image at different angles, your eyes perceive stereo vision giving the illusion of depth. You can see his results in the video below.

Honestly, even if you don’t want to make a display like this yourself, the demonstration of how a lenticular lens works using a laser is worth watching. Sure, you know in theory what’s going on, but seeing it visually exposed is great.

Continue reading “3D Printed Lenticular Lens Makes 3D Display”

Credit For Clever Corner Clamp

We love this design’s simplicity, but its mundane appearance is deceptive because a lot is going on here. [Bas van Hassel]’s clamp looks like a bench cookie or maybe a compressed hockey puck, but one pie piece-shaped quadrant extends on dovetails to form a right-angle channel, perfect for holding your ninety-degree joint while your glue dries. Opposing disc edges are flat, so your clamp won’t slip. Divots on the top and bumps on the bottom keep your stacks nice and neat when you put them away. All around, we have no trouble believing this designer has spent a lot of hours in the woodshop.

As long as your wood pieces are the same thickness, it seems like a practical use of printer filament, but if you have different sizes, you can always pull the dovetail out of its groove. Thanks to the scaling feature built into slicing programs, we expect some precision makers to utilize this in projects like dollhouses and model airplanes. If you have a high-resolution printer, you could make some miniature tools to construct a flea circus set. At that point, you may need to make some smaller clamps.

Print orientation for the puck is straightforward as it is a print-in-place design, but sometimes it isn’t always clear, so listen to those who know better and don’t be afraid of gears in your vises.