Notices by Bernie (codewiz@mstdn.io), page 5

The "Pocket" tool in the "Part Design" workspace does exactly what I needed, but took me a while to find it among countless of unfamiliar tools offered by #FreeCAD.

However, most of the jargon and the concepts I'm learning to make this simple bracket should port across all modern #CAD packages.

Parametric #CADs let you specify constraints on the sizes, distances and angles between certain lines, which can be adjusted at any time.

After drawing the outlines of the HDMI and ETH connectors on the front face in the Sketch workbench, I wanted #FreeCAD to punch them as holes through the bracket's thickness.

I tried learning #Blender to model the HDMI + Ethernet bracket from scratch, but after a while I realized that a 3D modeler used modtly by animators doesn't make a good #CAD for mechanical design.

Now I'm following a bunch of beginner's tutorials for #FreeCAD. Typically, you'd start by drawing a flat XY sketch and later extrude it along the Z axis.

Parametric CADs let you specify constraints on the sizes, distances and angles between certain lines, which can be adjusted at any time.

@jxself I don't believe that a 12% peroxide solution could really catch fire: it's 88% plain water! Perhaps the fumes?

As an extra precaution, I'll start off with the keyboard case suspended above the surface of the peroxide.

The +/= key has shown the effectiveness of the alternative dry process, which is also said to yield more even results.

I'm kinda concerned that my UV led strips might illuminate things unevenly, so I'll come check every few hours and rearrange the parts if necessary.

#commodore #amiga #vintagecomputing #chemistry #retrobrighting

The finalized process appears to be safe enough to start treating our venerable #Amiga 3000 keyboard.

Apart from the space bar, the keycaps don't need #retrobrighting. A good wipe with Windex will do.

Before proceeding, I dipped the plastic shell in dishwasher soap and warm water for 15 minutes. This should remove any grease or dirt that might block our reaction.

#commodore #retrocomputing #vintagecomputing

The sacrificial PC keyboard turned shockingly pale after spending ~30h in my peroxide bath with UV light.

The +/= key, which was suspended above the liquid, is almost the same shade.

The minus and backspace keys are untreated, while the backslash key was only exposed to sunlight and then UV, but never went in with the peroxide.

Contrary to reports that #retrobrighting weakens plastic, as far as I can tell the material remained strong and normally flexible.

#chemistry #vintagecomputing

@rox_lukas It healed in just a couple of days, but I don't want to imagine what would would be like to dip the whole hand in my peroxide bath without rinsing it right away 😨

@penguin42 😲

And how many gallons of peroxide can I buy online before they raid my house, find this weird box glowing in purple light and go: "aha! take him away!", without letting me finish to explain retrobrighting and vintage computing?

@crypticcelery @jxself haha I *did* notice! I just didn't complain because I wasn't the one eating. I think @rubenquidam used a huge pan, large enough for unbroken spaghetti.

@jxself @crypticcelery Our common friend @rubenquidam cooked this recipe a while ago, and it's delicious.

As an Italian, I was a bit horrified to see raw spaghetti thrown directly into a frying pan! 😆

While hydrogen peroxide (H2O2) is commonly used to disinfect wounds and even for oral rinsing, at 12% concentration it must be handled with gloves.

I touched the wet plastic with my bare fingers, and after a few seconds they were stinging, and the skin was already partially corroded. ✌️😮

I guess that's why you can't purchase peroxide at higher concentrations from retail stores in the US.

#retrobrighting #chemistry

Meanwhile, the 12% peroxide arrived, and I poured the entire 1 gal bottle in my #retrobrighting reactor for another 24h session with that poor PC keyboard.

Notice the =/+ key sitting on top of a plastic weight to compare the effectiveness of the reaction in air.

#vintagecomputing #chemistry

My second #retrobrighting experiment with sodium carbonate for 24h ended with a slightly paler PC keyboard.

The result is very uneven and the engravings look bleached. I'd call it a failure: don't bathe your vintage plastic in sodium carbonate!

The two controls on the left have been kept outside the box (backspace) and inside, but suspended above the liquid (equals/plus).

@RockyBoulder It was a fun learning experience for me.

I didn't credit them enough, but I got lots of guidance and advice from the awesome people on Acill Classics and a very knowledgeable guy from Tokyo Hackerspace.

@ellie I expected something like that 😂

By the way, thank you for making Atuin, it's full of awesomeness ❤️

@GuillaumeRossolini Sounds like a fun and very useful project!

Don't make my mistake of trying to get all the tools you need to build it at home: go to your local hackerspace and buy only the tools and parts they don't already have. You'll save time and benefit from the experience of others.

Today I also did a quick 3D-printing test for a pass-through bracket to bring HDMI and Ethernet ports of the Z3660 to one of the Zorro slots behind the A3000 case.

Since I suck both at CADs and 3D printing, I downloaded an STL file for a dual-HDMI bracket as a starting point.

I didn't expect the first try to be perfect, but I was surprised to find that someone had designed and shared a bracket skewed the wrong way! 😂

Or... do Zorro and PCI have opposite chirality? 😲

#amiga #retrocomputing

And voilà! The RTCPWR pin is receiving 3.3V and the oscilloscope confirms that the little quartz is ticking! 🎉

#commodore #amiga #retrocomputing #vintagecomputing #electronics

And that's it... phew! 😌

Now I just need to solder the battery holder on top of it and the 3 legs underneath...

#electronics #retrocomputing #vintagecomputing #amiga