A segmented lamp made of circular slices of plywood. They are arranged as shutters around a long, skinny LED bulb in the center that gives off an incadescent-looking glow. A cord trails off to the left against the grey background.

Plywood Lamp Has Customizable Light Output

November 1, 2022 by 2 Comments

There’s something about light fixtures that attracts makers like moths to a flame. [danthemakerman] wanted something with a more configurable light output and built this Sculptural and Customizable Plywood Lamp.

In his detailed build log, [danthemakerman] describes how he wanted something “sort of like an analog dimmable light.” By using a stack of split plywood donuts hinged on a brass rod, he can vary the output and shape of the lamp. These shutters allow the lamp to go from bright to nightlight without using any electrical dimming components.

The plywood was rough cut on a bandsaw before being turned on a lathe. The light cover sections were then hollowed out with a Forstner bit and split in half. The tricky bit is the overlap of the cut on the hinge side of the shutters. Cutting the piece exactly in half would’ve required a lot more hardware to make this lamp work than what was achieved by patient woodworking.

If you’d like to see more ways to make light fixtures with plywood, check out this Hexagonal Lamp, these Upcycled Plywood and Glass Lamps, or this Laser-cut Sphere Lampshade that Packs Flat.

Linux Fu: Easy VMs

November 1, 2022 by 34 Comments

It wasn’t long ago that we looked at easily creating Docker containers from the command line so you could just easily spin up a virtual environment for development. Wouldn’t it be nice if you could do the same for virtual machines? You can. Using Multipass from Canonical, the makers of Ubuntu, you can easily spin up virtual machines under Linux, Mac, or Windows. Granted, most of the virtual machines in question are variations of Ubuntu, but there are some additional images available, and you can create your own.

Once you have it installed, starting up a new Ubuntu instance is trivial. If you have a set configuration, you can even set up predefined setups using a YAML file.

Continue reading “Linux Fu: Easy VMs” →

Exploring Piston Engine Design With LEGO

November 1, 2022 by 16 Comments

When learning about the design of a machine or mechanism, reading and watching videos is certainly effective, but it’s hard to beat hands-on experimentation. In the video after the break, [Brick Technology] uses LEGO to gain some practical insight into the world of piston engine design, from single-cylinder all the way up to radial twelve-cylinder engines.

Using pneumatic cylinders from the LEGO Technic series, [Brick Technology] starts by getting the basics working with a single-cylinder design. Besides the fact that there are no fuel-air explosions involved, these pistons are also double-acting thanks to a valve mechanism that switches the pressurized side of the piston as it reaches the end of its stroke. After a couple of experiments, he settles on using a bank of six two liter soda bottles as a source of pressurized air.

He also increased the performance of the LEGO cylinders by drilling out the ports and adding silicon oil for lubrication. In the initial prototypes, the cylinders also acted as connecting rods, tilting back and forth as the crankshaft rotates. After some testing, he discovered he could increase efficiency by constraining the cylinder with a slider mechanism and adding a separate connecting rod.

With the basics done, [Brick Technology] could start experimenting with engine arrangements and geometry. Inline two, three, and four cylinders and V2, V6, V8, and even R12 were all on the menu. He could also change crankshaft geometry to trade torque for RPM and vice versa, and build a starter motor, and torque generator.

Just like [Brick Technology]’s LEGO electronic drums and vortex machine, this video gives us a itch that can only be scratched by a few hundred LEGO pieces. For rapid prototyping of course.

Identify That Antenna By Sight

November 1, 2022 by 75 Comments

It’s a skill that radio amateurs pick up over years but which it sometimes comes as a surprise to find that is not shared by everyone, the ability to casually glance at an antenna on a mast or a rooftop and guess what it might be used for. By which of course I mean not some intuitive ability to mentally decode radio signals from thin air, but most of us can look at a given antenna and immediately glean a lot of information about its frequency and performance. Is this privileged knowledge handed down from the Elmers at the secret ceremony of conferring a radio amateur’s licence upon a baby ham? Not at all, in fact stick around, and I’ll share some of the tricks. Continue reading “Identify That Antenna By Sight” →

DeltaPen: Drawing, Painting And Taking Notes Without The Drawing Tablet

November 1, 2022 by 24 Comments

Over the decades, a lot of attempts have been made to try and make pens and pencils “smart”. Whether it’s to enable a pen to also digitally record what we’re writing down on paper, to create fully digital drawings with the haptics of inks and paints, or to jot down some notes on a touch screen, past and present uses are legion.

DeltaPen internal components and their function. (Credit: SIP, Guy Luethy et al.)
DeltaPen internal components and their function. (Credit: SIP, Guy Luethy et al.)

Where SIP Lab’s DeltaPen comes in as an attempt at a smart pen that acts more like the pen of a drawing tablet, just minus the tablet.

This project is related to the decidedly more clumsy Flashpen which we featured previously. Due to the use of new flow sensors, the underlying surface (e.g. a desk) can be tracked without needing to be level with it, which allowed for the addition of a pressure-sensitive tip.

In addition the relative motion of the pen is measured, and there is haptic feedback, which allow for it to be used even for more delicate applications such as drawing. The results of trials with volunteers across a range of tasks is described in their presented paper (PDF).

Continue reading “DeltaPen: Drawing, Painting And Taking Notes Without The Drawing Tablet” →

The Best Threaded Holes For Resin Parts

November 1, 2022 by 21 Comments

Threaded inserts are great for melting into FDM prints with a soldering iron. The process isn’t so simple for resin prints, since they don’t generally soften with heat. Off course, you can also print the threads directly, screw a bolt into an un-threaded hole, or tap a hole. Following his usual rigorous testing process, [Stefan] from CNC Kitchen investigated various ways of adding threaded holes to resin prints.

After establishing a pull-out force on PLA using threaded inserts (205 kg) and tapped holes (163 kg), [Stefan] tested parts printed with Prusament Tough Anthracite resin. Un-threaded and tapped holes failed at 44 kg and 55 kg respectively, while printed threads were almost twice as strong, reaching 106 kg before breaking. Stephan also tried gluing inserts into the parts using resin and CA glue. The resin didn’t cure properly in the opaque parts (6 kg) while CA was comparable to plastic threads, failing at 52 kg.

Chart of results
TLDR: Print your threads for best results

[Stefan] also tested regular ELEGOO Translucent resin. The higher hardness of the cured resin allowed the parts to hold on to around 100 kg for un-threaded and tapped holes, while printed threads reached 120 kg. Threaded insert glued with resin did better on the transparent parts thanks to improved UV penetration, but were very inconsistent. Inserts glued with CA performed about the same as on the Prusament parts, failing at 56 kg.

In an attempt to improve the performance of the inserts [Stefan] printed some parts with stepped holes to match the geometry of the inserts, which had the advantage of preventing the insert from falling through during gluing. It only made a marginal difference on the Prusament parts but boosted the strength of CA-glued inserts on the ELEGOO resin to 82 kg. Two-part epoxy was also tried, which matched the un-threaded holes in strength.

So for resin parts you’ll probably be best served by just modeling the threads in CAD and printing them directly. If you need to be able to repeatedly screw and unscrew fasteners in a hole without stripping, threaded holes with CA or epoxy might be a better solution.

Continue reading “The Best Threaded Holes For Resin Parts” →

An Easy-To-Make Pi-Powered Pocket Password Pal

October 31, 2022 by 16 Comments

Sometimes, we see a project where it’s clear – its creator seriously wants to make a project idea accessible to newcomers; and today’s project is one of these cases. The BYOPM – Bring Your Own Password Manager, a project by [novamostra] – is a Pi Zero-powered device to carry your passwords around in. This project takes the now well-explored USB gadget feature of the Pi Zero, integrates it into a Bitwarden-backed password management toolkit to make a local-network-connected password storage, and makes a tutorial simple enough that anybody can follow it to build their own.

For the physical part, assembly instructions are short and sweet – you only need to solder a single button to fulfill the hardware requirements, and there’s a thin 3D-printable case if you’d like to make the Pi Zero way more pocket-friendly, too! For the software part, the instructions walk you step-by-step through setting up an SD card with a Raspbian image, then installing all the tools and configuring a system with networking exposed over the USB gadget interface. From there, you set up a Bitwarden instance, and optionally learn to connect it to the corresponding browser extensions. Since the device’s goal is password management and storage, it also reminds you to do backups, pointing out specifically the files you’ll want to keep track of.

Overall, such a device helps you carry your passwords with you wherever you need them, you can build this even if your Raspberry Pi skills are minimal so far, and it’s guaranteed to provide you with a feeling that only a self-built pocket gadget with a clear purpose can give you! Looking for something less reliant on networking and more down-to-commandline? Here’s a buttons-and-screen-enabled Pi Zero gadget that uses pass.