George Bryant @gbrnt@mastodon.technology

Today is my first time going back into the office since lockdown started. I think that's pretty good going for someone who designs physical things!

Jorts As A Service

I was kinda annoyed by unplugging my headphones from my DAC to switch to my monitor's soundbar, so I built a little audio switcher with a 3PDT switch. Haven't got round to designing the top and bottom of the enclosure or deciding where to mount it yet.

It works well other than that I somehow switched the left and right channels on one socket! Luckily the soundbar is almost mono anyway, the speakers are so close together.

I've improved the filter situation in my 3D printer enclosure. I'm pretty sure the old filter wasn't doing much because the activated carbon layer was basically non-existent. I've replaced it with the square foam filters you get for soldering iron fumes.

That made mounting the fan to the top of the enclosure easier because the filter is lighter, with a quick single-walled holder.

I published the design on Thingiverse at https://www.thingiverse.com/thing:4495222

Not very well written up but it might be useful to somebody.

I printed the design on its side, with a long bridge across the left side. It turned out well, and I finally finished the first roll of filament I bought!

So far it works really well - I've only printed tape holders but I'm looking forward to getting a bunch of my tools installed on it.

For the desk mounts, I already had an idea formed in my head and didn't feel the need to sketch it out. The process has already taken long enough by this point and I can always replace them later with an improved version. Using the dimensions from the pegboard I designed an initial version of the desk mounts in FreeCAD.

I set some threaded inserts into the part by heating them with my soldering iron. These are a great way to get proper threaded holes in a 3D printed part, and they're much less fiddly than embedding nuts into the part while printing.

On to the 3D printing! I printed two test pieces at 0.2mm layer height - they look good enough for this!

This is one of those cases where I didn't realise quite how tiny the parts are until I made them. I'm glad I made the main part wider than I thought it needed to be.

It fits into the pegboard nicely - with a tiny bit of wiggle, so I refined the CAD file, but didn't bother re-printing.

Whoops, forgot image descriptions:

1. Boxy design for back piece, copied from the technical drawings.

2. More rounded design for the same part, with the part that goes through the pegboard shortened to provide clearance.

I was already making changes for 3D printability here. I wanted to have a fillet (rounded edge) on the back section, but that means it starts printing at a tangent to the bed. In my experience that often doesn't print very well, so I changed it to a chamfer with a fillet.

The technical drawing made the design easy to draw up in CAD, but some dimensions needed changing to make the proportions look right.

I made up most of the dimensions as I went based on experience and educated guesses. Here's the part as I originally sketched it, versus what I ended up with after making it in CAD.

I thought I'd use FreeCAD for this project because it's free and open source software, and it's good enough for simple mechanical parts like this. For more complex shapes I'd prefer to use Rhino, but I have to boot into Windows for that.

FreeCAD is also parametric so I can adjust dimensions later if I 3D print a test piece and find it doesn't fit right. The interface is a little clunky, but I find it easier for simple parts like this than OpenSCAD.

The hinge is a little overbuilt to hopefully reduce the chance of the PLA gradually deforming and the door sagging. If that happens I'll have to try another strategy.

I'm still holding the door closed with tape, until I print some latches for it. It might even be a good place to use some magnets!

Which reminds me, I haven't shared any photos of the enclosure I've been building.

The printer has had a couple of Lack tables around it for about a year, but I never got round to putting sides on because it's expensive.

Recently I've been printing things for work and in return my company is paying for me to put on sides and an air filter.

Here are a few progress photos of that, including the hinges I designed for it.

I upgraded the firmware on my Ender 3 to the newest Marlin firmware, which I hadn't done since buying the silent mainboard for it.

I'm pretty sure it's treating the stepper drivers as non-silent ones and so making a bit more noise than usual. Now that I have it in an enclosure with a fan and filter running it's hard to tell.