Reviews

268 Articles

Review: DevTerm Linux Handheld Has Retro-Future Vibe

March 2, 2022 by 32 Comments

It’s not every day that an open-source, portable Linux handheld computer gets announced, so I couldn’t resist placing an order for the DevTerm by ClockworkPi back when we first learned about the stylish little terminal, which includes a 1280 x 480 screen (double-wide VGA) and a modular little thermal printer.

Of course, the global semiconductor shortage combined with shipping slowdowns led to delays, but things did ultimately come together for the project. I’ve always been a sucker for small-format machines, especially ones that come as a well-designed kit, and that means I can tell you all about what it was like to put it together and turn it on. There’s a lot to look at, so let’s get started.

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$60 PC Oscilloscope Review

February 26, 2022 by 46 Comments

Owning an oscilloscope is a real gamechanger and these days, scopes are more capable and less expensive than ever before. However, there is a big difference between scopes that cost several hundred dollars which are usually quite good and many of the very inexpensive — below $100 — instruments that are often — but not always — little more than toys. [Adrian] looks at a PC-based scope from Hantek that costs about $60. Is it a toy? Or a useful tool? He answers the question in the video below.

The Hantek 6022BE sports two channels with a 20 MHz bandwidth and 48 million samples per second. The device included probes, too. Of course, you also need a PC, although there is apparently third-party software for Android if you don’t want to lug a laptop around.

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3D Printer Showdown: $350 Consumer Vs $73,000 Pro Machine

January 29, 2022 by 35 Comments

The quality of consumer-grade 3D printing has gone way up in recent years. Resin printers, in particular, can produce amazing results and they get less expensive every day. [Squidmar] took a miniature design and printed it (or had it printed) on some cheap resin printers and a 65,000 Euro DWS029. How much difference could there be? You can see for yourself in the video below.

We were surprised at the specs for the more expensive machine. It does use a solid-state laser, but for that cost, the build volume is relatively small — around 15 x 15 x 10 cm. There were actually five prints created on four printers. Three were on what we think of as normal printers, one was on the 65,000 Euro machine, and the fifth print was on a 10,000 Euro printer that didn’t look much different from the less expensive ones.

Of course, there is more to the process than just the printer. The resin you use also impacts the final object. The printers tested included a Phrozen 4K Mini, a Phrozen 8K Mini,  a Solos Pro, and the DWS 029D. The exact resins or materials used was hard to tell in each case, so that may have something to do with the comparisons, too.

Do you get what you pay for? Hard to say. The 8K and Solos were neck-and-neck with some features better on one printer and some better on the other. The DWS029D did perform better, but was it really worth the increase in price? Guess it depends on your sensitivity. The 8K printer did a very credible job for a fraction of the cost. Of course, some of that could have been a result of the materials used, too, but it does seem likely that a very expensive dental printer ought to do better than a hobby-grade machine. But it doesn’t seem to do much better.

The DWS printer uses a laser, while most hobby printers use UV light with an LCD mask. We’ve seen low-end resin printers on closeout for around $100 and you can get something pretty nice in the $200 neighborhood. In between these two extremes are printers that use Digital Light Processing (DLP).

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Books You Should Read: The Perfectionists

January 7, 2022 by 28 Comments
After pulling late hours in my school machine shop for a few years, I couldn’t help but wonder, who measures the measurement tools? How did they come to be? I’d heard anecdotes from other students and engineers while they inspected my freshly machined parts, but these stories were one-offs. What I wanted was a tale of industrial precision from start to finish. Years later, I found it.

The story of precision, as told by Simon Winchester, is captured in The Perfectionists: How Precision Engineers Created the Modern World. Published in 2018, Winchester’s overview stretches as far back to the Antikythera mechanism and brings us to present day silicon wafer manufacturing. Of course, this isn’t a chronology of all-things made precisely. Instead, it’s a romp through engineering highlights that hallmark either a certain level of precision manufacturing or a particular way of thinking with repercussions for the future. Continue reading “Books You Should Read: The Perfectionists” →

TFT35 Dual Mode 3D Print Control – Hands On

January 3, 2022 by 18 Comments

I was rebuilding one of my 3D printers — again — and decided I needed a display upgrade. A color screen is nice, but there are some limitations. I also found there are ways around these limitations, so I wanted to share my thoughts on a dual-mode color touch screen LCD controller for your 3D printer. The screen in question is a TFT35 from BigTree Tech. It is similar to an MKS screen, but it can operate in two different modes, as you will see.

A few years ago, I picked up an Anet A8 which was very inexpensive, especially on sale. Not the best printer, though, because it has that cheap acrylic frame. No problem. A box full of aluminum extrusion later, the printer was reborn. Over time, I’ve completely reworked the extrusion system and the Y-axis, leaving only the motors, bearings, and the controller/display as the original.

That last part was what bothered me. The Anet board is actually pretty capable for a small cheap board. But it is just what the printer needs and nothing more. If you wanted to hack the printer there was very little memory left and only one spare pin for I/O. So it was time to replace the board and why not the controller, too?

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Ham Radio SSB Transceiver Fits In Pocket

December 9, 2021 by 32 Comments

Talking about this Chinese ham radio transceiver requires a veritable flurry of acronyms: HF, SSB, QRP, and SDR to start with. [Paul] does a nice job of unboxing the rig and checking it out. The radio is a clone of a German project and provides a low-power radio with a rechargeable battery. You can see his video about the gear below.

SSB is an odd choice for low power operation, although we wonder if you couldn’t feed digital data in using a mode like PSK31 that has good performance at low power. There are several variations of the radio available and they cost generally less than $200 — sometimes quite a bit less.

There isn’t much on the front of the radio. There are a few buttons, a rotary encoder, and an LCD along with a speaker and microphone built-in. There are ports for power to run the radio if you want to not use the battery and a separate port for battery charging. There are also ports for a key, external microphone and speakers, and audio connections that look like they’d work for digital modes. According to commenters, the radio doesn’t have an internal charging circuit, so you have to be careful what you plug into the charging port.

Looking inside, the radio looks surprisingly well made. Towards the end of the video, you can see the radio make some contacts, too. Looks like fun. This is a bit pricey for [Dan Maloney’s] $50 Ham series, but not by much. You might borrow an antenna idea from him, at least. If you prefer something more analog, grab seven transistors and build this SSB transceiver.

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Multimeters Go Big Screen

December 7, 2021 by 54 Comments

We’ve noticed lately that some cheap meters have gone to having big colorful screens. The screens aren’t dot matrix, but still have lots of graphics that could be useful or could be distracting eye candy, depending. The really cheap ones seem more like a gimmick, but [OM0ET] took a look at one that looked like a fair midrange instrument with some useful display features, the GVDA GD128.

A lot of the display shows the current function of the meter. No need for an expensive multiposition switch or rows of interlocking pushbuttons. Many of these new meters also have non-contact voltage sensors, which is handy. Otherwise, it looks like a pretty conventional cheap meter. Continue reading “Multimeters Go Big Screen” →