First steps in paint weathering

For an upcoming LARP we are using Bopits for some concentration tests. These are childrens' toys that are a bit like 'Simon' but you hold them in your hand and twist/push/pull various bits in response to voice prompts.

In the game fiction these are supposed to be tools but it has always grated on me that they just look like toys, so I'm stripping them down and having a go at changing the look. This is stock in trade to cosplayers and replica makers but normally I don't bother much with it. I've got a few different ones to work on but so far it's going OK.

I'm going for a well worn look, might have overdone it slightly but it's already much better than gloss white. The weird rubbery lumps sticking out at either end might get replaced with more tool-like 3D printed pieces.

Trying Elementary OS and saving waste

I make no apologies for being a Windows desktop user in a very Linux heavy community. For all the "Linux is better" sentiment I've always struggled to deal with its deficiencies as a desktop OS.

However I decided to make a foray into using it more on the desktop as I feel 'daily driver' use of Linux is a gap in my experience. A lot of this was prompted by recent versions of Elementary OS looking like a good candidate with a 'curated' app store from which things are supposedly going to 'just work'. Some are even paid for, at the sort of price you see on mobile apps, ie. 1-5$.

I'd thought about sticking Elementary alongside my desktop install, and even went as far as clearing the space on the SSD but then a 'free' laptop appeared at work. A colleague brought it in to go into our WEEE recycling but I snapped it up, much to the amusement of my team.

The machine is an old Acer V5-552 (quad core AMD A10 and 6GB RAM) which would have been pretty decent in its day but what I had in my hands was filthy, covered in cruft and greasy marks and had no HDD as that was taken out and smashed after failing.

It also transpired they didn't have the PSU, all the screws were missing from the base when they'd dismantled it and they'd set a BIOS password they couldn't remember. I had a little look under the base cover and found that it also had a nastily failing battery that I wouldn't consider safe to charge.

So yes it's a 'free' laptop but to most people a basket case and I sort of see that as a challenge. I hate stuff getting thrown out and I've wanted a 'disposable' laptop for a while.

Over the next few days I transformed it from trash to treasure for about £40.

• A really good clean with a microfibre cloth and warm water, removal of peeling stickers, cruft fished out of all the crevices etc.
• Fitment of a 120GB SSD taken from an older and slower laptop I had lurking a drawer.
• Fitment of a new battery supplied from Amazon for £23.99.
• Upgrade to 8GB RAM with a SoDIMM out of a machine going for recycling.
• BIOS password recovery using a code from https://bios-pw.org/.
• Use of a generic laptop PSU with changeable tips I got in the Maplin closing down sale for something like £5.
• Some generic laptop screws from a big eBay box that cost £6.
• Installation of Elementary OS 5.1, which has a suggested donation of $10.

Despite being nominally worse than my Zenbook by most criteria I really like it to use, mostly I think because I like the screen, keyboard and feeling of solidity. It's also not short of connectivity with a wired Ethernet, full size HDMI and so on. The performance is good as Elementary is quite lightweight and the quad core A10 is still acceptable for light use.

After a few days with Elementary I've found that the curated apps are relatively rare and you resort to installing generic Debian versions of most things. There are a few bugs to do with the way Elementary is skinned, notably some apps end up with a double title bar and you need to manually edit the shortcuts to fix this (edit the shortcuts in /usr/share/applications and add env GTK_CSD=0 to the Exec= line). Also Dropbox works but took some fighting to install and doesn't integrate with the desktop at all.

Sadly though Bluetooth mouse support is execrable, they work for a bit then fail and kill the ability to click with the pointer on some elements and the Bluetooth status app (sometimes the whole status bar). I can live with the appearance gremlins but that's really poor for a 'curated' distro and is the kind of thing that reminds me why I've given up on Linux desktops before. I need a mouse for working with KiCAD, which is one of the things I'm learning, and I can see myself falling back to carrying a wired mouse around. Irritating, but I'll persevere as otherwise it's working nicely.

Creality Ender 3

I've come to really like the cheap Creality Ender 2 3D printer I bought a while back but have found the small build area limiting. Then a Banggood Black Friday sale spat out an Ender 3 for £129 and I couldn't resist it. Shipped from the EU it came in just two days but I had to wait until I had some free time to put it together.

The improvements in design and packing over the Ender 2 are really obvious.  It's not complicated to assemble, if you can build IKEA furniture you can do this. Every little bag of components is clearly labelled, right down to the bolts, which come with matching washers already threaded onto them. You even get cheap but usable examples of the tools needed supplied. I would really recommend one of these if you want a minimally viable cheap 3D printer. Contenders for 'best value' come and go but the Enders are a consistently safe bet. The contrast with my Ormerod is striking, things have really moved on.

There's a massive modding community for these but I've shied away from doing anything to it at all. When I remember I'll put a neoprene 'sock' around the hot end to stop stray filament sticking and that's mostly because I got a pack of two when I bought one for the Ender 2.

Makevember 2019

This year I stumbled onto something Dominic Morrow started, Makevember.

The original concept outlined in his blog is to do something 'new' and time limited, but like a lot of others participating I ended up using it as an impetus to work on things most days of November even if it wasn't something particularly new or quick.

I've found this was massively helpful. I've been tackling loads of 'round tuit' things, over the last month I have...

• Mounted my laser engraver on a board, fitted end stops, rebuilt LaserWeb and made the software changes to make auto-homing work. This turned it from a dust gathering ornament into a much more usable tool.
• Familiarised myself with the workflow for my SLA 3D printer and printed things for a friend.
• Built a UV curing enclosure for output from my SLA 3D printer.
• Fixed up an old medical analyser prop.
• Fixed up my Orac prop as it had developed a couple of faults.
• Fixed up my Enigma Machine prop so the keycaps were more robust and the gaps round the LED matrix displays were filled.
• Made a set of 12V spotlights using Poundland LED GU5.3 units.
• Experimented with a cheap pico-projector for future use in a new prop.
• Learned basic use of Meshmixer.

This has been a really positive experience and shows how an incentive can work. If I can keep up this focus the rest of the year then it will be a very productive one.

Photon printing progress

I've finally started using my Anycubic Photon for something after a casual chat with a friend showed they wanted some custom parts made for collectable action figures.

When the thing somebody wants already exists on Thingiverse and you've got an SLA printer this kind of thing becomes an easy favour to do and it has the added benefit of giving you an excuse to get more experience with the printer.

Levelling the bed and slicing with appropriate supports is definitely a learning exercise and I've had a few failed prints, which are annoyingly wasteful of resin.

In the end watching a few YouTube videos got me to this good process for levelling. There seems to be a lot of superstition about the levelling process with vocal adherents for different methods but I'm now getting good prints with this variant.

• Cut a piece of copier paper so it fits where the vat would go and so you can pull it back/forth from the front.
• Loosen the hex screw in the middle of the build plate so it can move around on the ball joint.
• CAREFULLY lower the build plate onto the paper (no vat) until it touches.
• Lower it slowly, 0.1mm at a time until the paper is firmly held and can't be pulled.
• Tighten the hex screw while putting light downward pressure on the build plate so it's firmly against the paper and screen.
• Raise the build plate 0.3mm.
• Lower the height of the build plate 0.1mm at a time until you can pull the paper out from underneath, but you can't push it back in. You may need to go back and forth a few times.
• Set this as zero through the menu.
• You do not need to do this every time, even if you've removed the build plate to extract a print.

Now I'm printing a few of the same thing in different sizes so my friend can try them with the figure, my first guess was perhaps a little oversize but the level of detail is fantastic. It's even better than it looks from the photo.

ESP32-VGA board from Bitluni

There's been a ton of work done by various people to make the ESP32 do things nobody ever really expected. One of those is to output quite decent VGA video.

In principle this is done with just some resistor ladders but building a board to do this is a bit fiddly so I've just picked up one from Bitluni on Tindie.

I don't have an immediate use for this but the vague plan is to use it as some kind of display interface that speaks to my mesh network kit. Connect a PS/2 keyboard and you've got a terminal device based on a microcontroller, rather than using a Raspberry Pi as a bit of middleware and this appeals to me greatly.

YG300 pico projector

I have in mind to build a handheld prop that projects information as you hold it.

What I'm not sure about yet is how this will be implemented but I've been thinking about building a low resolution matrix of lasers and doing something with persistence of vision as you move it.

Which may of course be completely impractical. 

I also saw these pico projectors on sale for only £30 and have picked one up as a more realistic cheap solution. You get what you pay for, they're only a 320x240 resolution, but it does work.

With a Raspberry Pi connected video playback of 4:3 SD content with omxplayer is actually perfectly acceptable for your £30. It's very dim, you have to use it in total darkness but turn the lights off and it's watchable. It'll also play off USB/SD.

To see what's inside I did a teardown. It's all quite predictable, some fresnel elements, a mirror to turn the image through 90 degrees, an LCD shutter and a COB LED illuminator with a big heatsink.

These can take an optional battery pack and there's a space behind the mirror for this. I did a little poking around with a meter and there are three unused connections on the top right of the board.

These connections are labelled B/R/Y

B - Ground
R - Battery positive, it expects a 2S Lipo pack so ~7.2-8.4v
Y - Supply positive which by default is 12V

I assume there's a balance charger built into the battery pack as there seems to be no charging circuit on the board. It runs quite happily off these connections and provides a little battery meter on the menu screens.

Using these connections seems perfectly reasonable although I can see myself making them external rather than squeezing them into the case.

I'd like to run this off a Raspberry Pi Zero, although equally something like an ESP32 can be wired up very easily to generate composite video. At 32x240 it really doesn't need to connect over HDMI.

Space inside is very limited but it would not be impossible to 3D print a replacement case that spaces the elements out like they are in in the original.

It could perhaps make for an interesting "pepper's ghost" setup that emulates a sci-fi hologram projector, just so long as it's in the dark.

EleksLaser end stops

I've had this laser engraver for quite some time but not used it as much as I originally expected.

Lots of that is because it is quite bulky so I can't leave it taking up a table and it's then a bit of a pain in the neck to set up every time, with lots of dangling cables and connections. So over the last couple of evenings I spent a bit of time screwing it down to a mounting board and making it portable.

Once I'd done this I was reminded that it doesn't have any end stops and is prone to hitting the end of travel if you're not careful. This irritates me more than it should as it doesn't actually do any damage, but it can waste loads of time making you set it up afresh with every run and occasionally ruining a job.

I did a little reading round the topic and decided to add end stops and configure it so it will auto-home. This is supported by GRBL but not the controller board supplied, it omits the connectors as well as the limit switches. It is however straightforward to solder the limit switches direct to the bottom of the board.

It was a real surprise to me there was no complete how-to for this even though the information is pretty freely available. So I wrote one and put it up with the designs for the switch holders on Thingiverse.

I'm still using LaserWeb to drive this but thinking about purchasing a copy of  LightBurn as it's quite affordable.