FreeCAD Is Near 1.0

September 21, 2024 by 48 Comments

The open-source parametric 3D modelling software, FreeCAD, is out in a release candidate for version 1.0.  If you’ve tried FreeCAD before and found a few showstoppers, it might be a good time for you to test it out again because the two biggest of them have been solved in this latest version.

First, version 1.0 finally implements a solution to the “topological naming problem”. Imagine you want to put a hole into a surface. The program needs to know on which surface to put the hole, and so it refers to this surface by name / number. Now imagine you subdivide the surface, and both subsections get new names. Where does your hole go now?  If you want to dig into the issue, the inimitable [MangoJelly] has a great video about the topo naming problem. Practically, there were workarounds, like only adding chamfers after the main design has stabilized, but frankly it was a hassle to remember all of the tricks. This is a huge fix.

The second big fix concerns assemblies.  Older versions of FreeCAD were great for making single parts, but combining them all together inside the CAD program was always janky.  Version 1.0 combines the previous two patchwork assembly workbenches into one, and it’s altogether more pleasant to use. The constraints of how two parts move when held together with an axle just works now, and this is a big deal for multi-part models.

If you’re coming from any other parametric CAD program, most of FreeCAD will seem familiar to you, but there will also be workflow differences that will take some getting used to. In trade, what do you get? Scriptability in Python, real open source software, and all of the bells and whistles for free. Now that its two biggest pain points have been addressed,  FreeCAD has become a lot easier to love. We’re looking forward to some good V1.0 tutorials in the future, and we’ll keep you posted when we find them.

Upgrading The E-mu Audity 20 Years After Factory Support Ended

February 8, 2026 by 18 Comments

If you purchased an E-mu Audity 2000 ROMpler back in 1998, you almost certainly got a rig with the 1.00 firmware. It was fine, if a little limited, particularly where upgradability was concerned. E-mu would later offer firmware upgrades over MIDI with the 2.00 firmware, but to get the 2.00 firmware, you needed to ship the box back to E-mu. Or you did… until now.

Realizing that E-mu is long gone and they weren’t going to handle any further firmware upgrades, [Ray Bellis] set about finding another way to help aggrieved operators with gear stuck on v1.00. [Ray] had managed to lay hands on a Audity 2000 service manual as well as the official 2.00 upgrade kit in an estate sale, and set about reverse engineering it to help the community. It turned out that upgrading from 1.00 to 2.00 required the use of a special boot ROM and a flash device containing the upgraded firmware image. Booting from the special ROM required the use of a jumper, and when engaged, the ROM would copy the updated image to the device itself.

[Ray] didn’t want to duplicate the standard upgrade device, as that seemed a little difficult what with parts availability in 2026. Instead, he crafted his own ROM that, with compression, contained the necessary firmware upgrade image and could all be stuffed inside a single 512 KB chip. All you need to do is flash the custom upgrade ROM to an AM29F040B PLCC32 NOR flash chip, pop it in the empty PLCC32 socket on the mainboard, and away you go. This will get you a machine upgraded to the final v2.01 firmware delivered by E-mu before its demise.

It’s a finicky bit of work, but it’s a great way to get new functionality out of an old Audity 2000. We’ve featured similar work before regarding aging Yamaha synths, too. If you’ve got your own backdoor methods for giving older music hardware a new lease on life, don’t hesitate to notify the tipsline.

How Accurate Is A 125 Year Old Resistance Standard?

January 16, 2026 by 43 Comments
Internals of the 1900 Evershed & Vignoles Ltd 1 ohm resistance standard. (Credit: Three-phase, YouTube)
Internals of the 1900 Evershed & Vignoles Ltd 1 ohm resistance standard. (Credit: Three-phase, YouTube)

Resistance standards are incredibly useful, but like so many precision references they require regular calibration, maintenance and certification to ensure that they stay within their datasheet tolerances. This raises the question of how well a resistance standard from the year 1900 performs after 125 years, without the benefits of modern modern engineering and standards. Cue the [Three-phase] YouTube channel testing a genuine Evershed & Vignoles Ltd one ohm resistance standard from 1900.

With mahogany construction and brass contacts it sure looks stylish, though the unit was missing the shorting pin that goes in between the two sides. This was a common feature of e.g. resistance decade boxes of the era, where you inserted pins to connect resistors until you hit the desired total. Inside the one ohm standard is a platinoid resistor, which is an alloy of copper, nickel, tungsten, and zinc. Based on the broad arrow mark on the bottom this unit was apparently owned by the UK’s Ordnance Board, which was part of what was then called the War Office.

After a quick gander at the internals, the standard was hooked up to a Keithley DMM7510 digital bench meter. The resistance standard’s ‘datasheet’ is listed on top of the unit on the brass plaques, including the effect of temperature on its accuracy. Adjusting for this, the measured ~1.016 Ω was within 1.6% tolerance, with as sidenote that this was with the unit not having been cleaned or otherwise having had maintenance performed on it since it was last used in service. Definitely not a bad feat.

Continue reading “How Accurate Is A 125 Year Old Resistance Standard?” →

How Big Is Your Video Again? Square Vs Rectangular Pixels

December 8, 2025 by 11 Comments

[Alexwlchan] noticed something funny. He knew that not putting a size for a video embedded in a web page would cause his page to jump around after the video loaded. So he put the right numbers in. But with some videos, the page would still refresh its layout. He learned that not all video sizes are equal and not all pixels are square.

For a variety of reasons, some videos have pixels that are rectangular, and it is up to your software to take this into account. For example, when he put one of the suspect videos into QuickTime Player, it showed the resolution was 1920×1080 (1350×1080). That’s the non-square pixel.

Continue reading “How Big Is Your Video Again? Square Vs Rectangular Pixels” →

This Week In Security: Cloudflare Wasn’t DNS, BADAUDIO, And Not A Vuln

November 21, 2025 by 8 Comments

You may have noticed that large pieces of the Internet were down on Tuesday. It was a problem at Cloudflare, and for once, it wasn’t DNS. This time it was database management, combined with a safety limit that failed unsafe when exceeded.

Cloudflare’s blog post on the matter has the gritty details. It started with an update to how Cloudflare’s ClickHouse distributed database was responding to queries. A query of system columns was previously only returning data from the default database. As a part of related work, that system was changed so that this query now returned all the databases the given user had access to. In retrospect it seems obvious that this could cause problems, but it wasn’t predicted to cause problems. The result was that a database query to look up bot-management features returned the same features multiple times.

That featurelist is used to feed the Cloudflare bot classification system. That system uses some AI smarts, and runs in the core proxy system. There are actually two versions of the core proxy, and they behaved a bit differently when the featurelist exceeded the 200 item limit. When the older version failed, it classified all traffic as a bot. The real trouble was the newer Rust code. That version of the core proxy threw an error in response, leading to 5XX HTTP errors, and the Internet-wide fallout. Continue reading “This Week In Security: Cloudflare Wasn’t DNS, BADAUDIO, And Not A Vuln” →

Better 3D-Printed Bridges Are Possible, With The Right Settings

November 5, 2025 by 17 Comments

The header image above shows a completely unsupported 3D-printed bridge, believe it or not. You’re looking at the bottom of the print. [Make Wonderful Things] wondered whether unsightly unsupported bridges could be improved, and has been busy nailing down remarkably high-quality results by exhaustive testing of different settings.

It all started when they thought that unsupported bridges looked a lot as though they were made from ropes stretched between two points. Unlike normal layers, these stretched extrusions didn’t adhere to their neighbors. They are too far apart from one another, and there’s no “squish” to them. But could this be overcome?

His experiments centered mainly around bridge printing speed, temperature, and bridge flow. That last setting affects how much the extrusion from the hot end is adjusted when printing a bridge. He accidentally increased it past 1.0 and thought the results were interesting enough to follow up on; it seemed that a higher flow rate when printing a bridge gave the nudge that was needed to get better inter-line adhesion. What followed was a lot of testing, finally settling on something that provided markedly better results than the stock slicer settings. Markedly better on his test pieces, anyway.

BF = Bridge flow, BS = Bridge printing speed (in mm/sec)

The best results seem to come from tweaking the Bridge Flow rate high enough that extrusions attach to their neighbors, printing slowly (he used 10 mm/sec), and ensuring the bridged area is as consistent as possible. There are still open questions, like some residual sagging at corners he hasn’t been able to eliminate, but the results otherwise look great. And it doesn’t even require laying one’s printer on its side!

All the latest is on the project page where you can download his test models, so if you’re of a mind to give it a try be sure to check it out and share your results. Watch a short video demonstrating everything, embedded just under the page break.

Thanks to [Hari] for the tip!

Continue reading “Better 3D-Printed Bridges Are Possible, With The Right Settings” →

No Plans For The Weekend? Learn Raytracing!

September 6, 2025 by 15 Comments

Weekends can be busy for a lot of us, but sometimes you have one gloriously free and full of possibilities. If that’s you, you might consider taking a gander at [Peter Shirley]’s e-book “Learning Raytracing in One Weekend”.

This gradient is the first image that the book talks you through producing. It ends with the spheres.

This is very much a zero-to-hero kind of class: it starts out defining the PPM image format, which is easy to create and manipulate using nearly any language. The book uses C++, but as [Peter] points out in the introduction, you don’t have to follow along in that language; there won’t be anything unique to C++ you couldn’t implement in your language of choice.

There are many types of ray tracers. Technically, what you should end up with after the weekend ends is a path tracer. You won’t be replacing the Blender Cycles renderer with your weekend’s work, but you get some nice images and a place to build from. [Peter] manages to cram a lot of topics into a weekend, including diffuse materials, metals, dialectrics, diffraction, and camera classes with simple lens effects.

If you find yourself with slightly more time, [Peter] has you covered. He’s also released books on “Raytracing: The Next Week.” If you have a lot more time, then check out his third book, “Raytracing: The Rest of Your Life.”

This weekend e-book shows that ray-tracing doesn’t have to be the darkest of occult sciences; it doesn’t need oodles of hardware, either. Even an Arduino can do it..