The Effect Of Filament Color On Print Strength And More

February 5, 2023 by 16 Comments

What is an FDM filament coloring’s purpose but to be an aesthetic choice? As it turns out, the additives that create these changes in coloring and transparency also affect the base properties of the polymer, whether it’s PLA, PETG, or another material. This is where a recent video by [CNC Kitchen] is rather illustrative, using a collection of colored PLA filaments from a single filament manufacturer.

[CNC Kitchen] ran a range of tests including tensile strength, ductility, layer adhesion, impact resistance, and annealing performance. The results showed no clear overall winner between plain PLA polymer and any specific color. Perhaps most fascinating was just how much these color additives change the material’s response to annealing. Baking the PLA at 100°C for 30 minutes generally improves material properties, but also can cause warping and shrinking. The effective warping and shrinking differed wildly between the filament.

The general conclusion would seem to be that the natural polymer isn’t necessarily the optimal choice, but that you should test and pick the filament from a specific manufacturer to fit your project’s needs.

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Sundial Collection Is 2D Printed

February 5, 2023 by 3 Comments

We see a lot of clocks, and many of the better ones have some 3D printed elements to them. But [Carl Sabanski] shows us his kits for making sundials for either hemisphere using a conventional printer (you know, one that puts ink on paper), some styrofoam, and possibly some other materials like wire coat hangers, threaded rods, thumbtacks, glue, and different papers like transparencies or card stock.

In all, there are 21 different kinds of sundials. Some are pretty standard-looking fare, but there are others, like the pinwheel equatorial sundial or the cycloid polar sundial, which might be surprising. One even uses a CD as a kind of indicator.

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3 Ways To DIY Custom CNC Dust Covers

February 4, 2023 by 7 Comments

Home shop machinists know dust shields are important for keeping swarf out of expensive linear rails and ball screws. [Petteri Aimonen] demonstrates three inexpensive ways to DIY some bellows-style dust covers. Such things can of course be purchased, but they’re priced at a premium and not always available in the size one needs.

A bellows-style dust cover ideally maximizes extension length while minimizing side wall distortion. It should hold its shape without external support.

The first method is to fold a suitable flat plastic or paper sheet into a bellows pattern. This method is all about the fold pattern, and thankfully, there’s no need to reinvent the wheel. [Petteri] used a fellow enthusiast’s bellows folding pattern generator which is, believe it or not, itself inspired by a remarkably comprehensive US Patent Number 6,054,194.

The downside to this method is the thickness of the bellows when it is fully collapsed. The corners always contain the most material, because it is there that the material is folded upon itself, and this limits how close to the end of travel the CNC carriage can move with the bellows attached.

The second method is to cut a large number of C-shaped sections from fabric and sew them together to make bellows. This method collapses down well and holds its shape well, but the cutting and sewing it requires can be a barrier.

The final method — and the one [Petteri] found most useful — was to hack some IKEA window blinds. IKEA Schottis pleated blinds are inexpensive, with a slick finish on one side and polyester fabric.  The polyester is perfect for gluing. By cutting the material at a 45-degree angle into three sections and gluing them into a U-shape, one can create a serviceable bellows-style cover for a minimum of work.

Any of the explored methods can do the job, but [Petteri] has formulas to determine the maximum extensions and folded thicknesses of each method just in case one would like to see for themselves before choosing. And if a bellows-style cover isn’t your cup of tea, check out this method for turning a plastic strip into a spring-like tube that does the same job.

Reliving A Bitmapped Past With A Veritable Hoard Of Bitmap Fonts

February 4, 2023 by 12 Comments

The fonts seen with old computer systems such as those from Apple and Commodore, as well as Microsoft Windows 3.1 and older, form an integral part of our interaction with these systems. These days such bitmap fonts are a rarity, with scalable vector-based fonts having taken their place on modern-day systems. This unfortunately also means that these fonts are at major risk of being lost to the sands of time. This is where [Rob Hagemans] seeks to maintain an archive of such bitmap fonts, ranging from Acorn to MSX to Windows.

Many of these fonts are extracted from character ROMs, with a preview of some of these fonts available via the Monobit viewer. The fonts themselves are made available in YAFF format, which is a text-based format that can be converted back to a binary format using the Monobit tool. If you ever wanted to use one of these old bitmap fonts in a project, this would seem to offer a treasure trove of options. The hoard of bitmap fonts might be the perfect fit for your next graphic LCD project.

(Via [SuperIlu] on Mastodon)

A visually accurate replica of the MCM/70 computer, an all in one system with a keyboard, dual cassette drives and a small one line display

MCM/70 Replica Embodies Proud Canadian Heritage

February 4, 2023 by 17 Comments

When a vintage computer is all but unobtanium, software emulation is often all that remains. Unless you are [Michael Gardi], who saw an opportunity to reproduce Canada’s home-grown MCM/70 microcomputer using a combination of software emulation and modern hardware.

Short of building a brand new MCM/70 from the original schematics, this faithful facsimile of the MCM/70 does everything it can to pay homage to the original machine. The foundations of this project can be attributed to the York University Computer Museum (YUCoM) MCM/70E emulator, highly regarded for its “historical accuracy”. The MCM/70 used dual cassette tapes for storage and a funky 32-character dot matrix plasma display, which is all reproduced in software (other versions dropped one of the cassette drives for a modem, bleeding edge innovation for 1974 microcomputing).

From here, [Michael] set off to assemble the various physical components of the original computer. The chassis itself was built from scratch using a mixture of 3D printing and traditional woodwork. The high-voltage plasma display was recreated using four HCMS-2972 dot matrix modules, which minor compromises. The original computer used display memory as extra storage when executing instructions, which created a sporadic blinkenlights effect on the original display. This new display unfortunately won’t reproduce this ‘thinking’ pattern, but it’s a small sacrifice.

Similarly, the original keyboard was going to be challenging to replicate with 100% accuracy, so a brand-new recreation of an Ohio Scientific computer keyboard was used instead. The layouts are extremely similar, and anyone except your most committed Canadian retro computing enthusiasts probably wouldn’t notice the difference. Being a modern recreation of a vintage keyboard, this was relatively easy to source. A set of custom-made keycaps with APL legends really helped sell the replica.

And while working dual cassette drives would have brought this project home, it’s commendable that [Michael] has created ‘working’ cassette drives using 3D printed cassettes and some magnetic magic using hall effect sensors to identify the loaded cassette. The emulator incorporates three virtual cassette tapes which made this solution possible.

If this all sounds familiar, it might be because this project was based on a superb Hackaday writeup of the MCM/70. A truly innovative computer for its time, the story behind Micro Computer Machines (not to be confused with the toy cars) is a fascinating tale, and the write-up is worth a read if you haven’t seen it already.

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A Commodore 64 accessing an online service

The WiC64 Brings Classic Commodores Online, Google Maps Included

February 4, 2023 by 29 Comments

A computing platform is never really dead unless people stop developing new software for it. By that measure, the Commodore 64 is alive and well: new games, demos, and utilities are still being released on a regular basis. Getting those new programs onto an old computer was always a bit of a hassle though, requiring either an SD card adapter for the Commodore or a direct cable connection from an internet-connected PC. Luckily, there’s now a simpler way to get your latest software updates thanks to a WiFi adapter called WiC64.  This adapter plugs into the expansion port of a classic Commodore and lets you download programs directly into memory. [Tommy Ovesen] over at [Arctic Retro] bought one and explored its many features.

The basic design of the WiC64 is straightforward: an ESP32 mounted on an adapter board that connects its data bus to that of the Commodore 64, 128 or VIC-20. A simple program, which you still need to transfer the old way, lets you configure the device and connect to a WiFi network. Once that’s done, an interactive BBS-style program is launched that allows you to access a range of online services. The WiC64 developers provide these, but since the system is fully open-source there’s nothing stopping you from running your own servers as well.

A street on Google Maps, rendered on a Commodore 64 Services currently available include an RSS reader, several multiplayer online games, and even a radio station that plays non-stop SID tunes. There’s also a direct link to CSDB, an online database of Commodore 64 programs and demos which you can now simply download and run directly on your C64 – in effect, a modern app store for a classic computer.

One feature that really seems to defy the C64’s hardware limitations is a fully functional version of Google Maps. Even with the Commodore’s limited resolution and color depth, it does a pretty decent job of showing maps, satellite photos, and even Street View images.

Using the WiC64 requires no hardware modifications to the Commodore 64, but a custom ROM is available that enables a few convenient features such as LOADing programs directly from a web address. There have been several attempts at getting classic Commodores online, but none so far that managed to get complex apps like Google Maps running. We have seen YouTube videos being played on a Commodore PET though.

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Fulcrum Foils Finger Fatigue

February 4, 2023 by 10 Comments

It turns out that typing all day just might be bad for your hands and fingers. Repetitive Strain Injury, RSI, was a real problem for [David Schiller], particularly when coding. So, naturally, he started designing his own keyboard. And bless him, he’s shared the whole project on GitHub.

The solution is Fulcrum, a chording keyboard with keys that can be pressed with minimal movement. And one more clever trick is a thumb joystick, mounted in the thumb’s opposable orientation. It’s a 5-way switch, making for a bunch of combinations. The base model is a 20-key arrangement, and he’s also designed a larger, 40-key option.

The build is pretty simple, if you have access to a 3D printer. Print the STLs, add key switches, and wire it all up to a microcontroller. Use the supplied code, and all that’s left is to learn all the chord combos. And why stop with combos for single characters, when there are plenty of common words and plenty of key combinations. If you decide to build your own take on the Fulcrum, be sure to let us know about it!