We’ve seen plenty of motor projects, but [Jeremy]’s DIY Tubular Linear Motor is a really neat variety of stepper motor in a format we certainly don’t see every day. It started as a design experiment in making a DIY reduced noise, gearless actuator and you can see the result here.

Here’s how it works: the cylindrical section contains permanent magnets, and it slides back and forth through the center of a row of coils depending on how those coils are energized. In a way, it’s what one would get by unrolling a typical rotary stepper motor. The result is a gearless (and very quiet) linear actuator that controls like a stepper motor.

While a tubular linear motor is at its heart a pretty straightforward concept, [Jeremy] found very little information on how to actually go about making one from scratch. [Jeremy] acknowledges he’s no expert when it comes to motor design or assembly, but he didn’t let that stop him from iterating on the concept (which included figuring out optimal coil design and magnet spacing and orientation) until he was satisfied. We love to see this kind of learning process centered around exploring an idea.

We’ve seen DIY linear motors embedded in PCBs and even seen them pressed into service as model train tracks, but this is the first time we can recall seeing a tubular format.

Watch it in action in the short video embedded below, and dive into the project log that describes how it works for added detail.

Turning surplus LCD panels into stand-alone monitors with the help of a driver board is an established hack, and a search of eBay or AliExpress will turn up boards for almost any widely available panel. [Drygol] has a couple of old iPad screens, and has done exactly this with them. What makes these two projects stand aside from the crowd is their attention to detail, instead of creating a hacky monitor this is almost something you might buy as a product.

For a start, both screens sit in very smart 3D printed cases. Behind them is the LCD driver, and perhaps this is where many people might leave it. But the point of an iPad is portability, so the first one receives a suitably large lithium polymer battery and its associated electronics. As such a thing is of limited use without a battery level monitor, so one is mounted flush with the case on the outside. The final touch is a Bluetooth audio board and speaker, making an all-in-one peripheral we’d be happy to carry with us.

The second screen is a slimmer version of the first case, with a different board that has an onboard audio channel. It’s mounted in a stand with a MiSter FPGA emulator, for a very neat and compact desktop set-up.

This project shows what can be done with these screens, and raises the bar. All the files are included, so it should be possible to make your own. We expect someone might stick a Raspberry Pi in there, to make… something like an iPad.

This isn’t the first time we’ve seen an iPad screen mod.

When building one-off projects, it’s common to draw up a plan on a sheet of paper or in CAD, or even wing it and hope for the best outcome without any formal plans. Each of these design philosophies has its ups and downs but both tend to be rigid, offering little flexibility as the project progresses. To solve this, designers often turn to parametric design where changes to any part of the design are automatically reflected throughout the rest, offering far greater flexibility while still maintaining an overall plan. [Cal Bryant] used this parametric method to devise a new set of speakers for an office, with excellent results.

The bulk of the speakers were designed with OpenSCAD, with the parametric design allowing for easy adjustments to accommodate different drivers and enclosure volumes. A number of the panels of the speakers are curved as well, which is more difficult with traditional speaker materials like MDF but much easier with this 3D printed design. There were a few hiccups along the way though; while the plastic used here is much denser than MDF, the amount of infill needed to be experimented with to achieve a good finish. The parametric design paid off here as well as the original didn’t fit exactly within the print bed, so without having to split up the print the speakers’ shape was slightly tweaked instead. In the end he has a finished set of speakers that look and sound like a high-end product.

There are a few other perks to a parametric design like this as well. [Cal] can take his design for smaller desk-based speakers and tweak a few dimensions and get a model designed to stand up on the floor instead. It’s a design process that adds a lot of options and although it takes a bit more up-front effort it can be worth it while prototyping or even for producing different products quickly. If you want to make something much larger than the print bed and slightly changing the design won’t cut it, [Cal] recently showed us how to easily print huge objects like arcade cabinets with fairly standard sized 3D printers.