Exactly how flat does a sharpening stone need to be? Exactly how flat, for that matter, does a plane need to be?

I’m on holiday. Here is a toy plane, a soft building block, and a half brick (not cut by me):

The plane started out rather rusty, as did the iron (why do I always forget to take ‘before’ photos?). The plane sole, lubricated with water, was used to flatten off the soft building block, and it was then used to take the rust off the iron. The half-brick did a much better job of sharpening, but it wasn’t perfect. Then I found a better stone:

Apparently one of the local bike thieves was eyeing up the bike. Certainly a car was driving down the road, crawling opposite the bike, and then driving off again. Having had one bike nicked I didn’t much fancy losing another. Thus we had to make the house look a lot more secure in a hurry; and the shops were closing that evening and not reopening till Tuesday. For it was the New Year.

We have a brick built shed with a concrete roof, which serves me as workshop. Unfortunately when we moved in the torched on felt (the proper three-layer system) had died in a large part, and water could make its way inside. Thus it needed re-roofing.

Now, whilst I have no experience roofing beyond tacking down felt on wooden roofs (which is infinitely simpler than what ended up happening), I immediately decided to volunteer to re-roof it if the landlord would pay. And since it made no sense to do one side, I offered to do the neighbour’s half as well (the shed is semi-detached). The reasoning at the time was that a proper reroofing job would be at least a grand, and the landlord was unlikely to volunteer that for a small leak. More likely he would put some sealer on; the problem would reappear; etc. (I have no evidence this would actually be the case as I did not ask him. But it’s what I’d likely do if someone said the shed was leaking—repair it for a year or so and try to get friendly with a roofer in the meanwhile.) Whereas I wanted to know the tools and wood inside were properly dry. And besides, I’d never done anything of the kind.

What do you do with a broken zipper? Especially early in the morning (i.e. around 1am).

Here is one way to repair a zip, preserving the latching effect to stop it falling down by itself. The wire rope (from ordinary copper stranded hookup wire) pulls the latching tooth, and the fairlead (made from two very small screws and some more wire soldered in place) converts enough of the tension into downwards force to move the zip. I have no idea how it has held up in practice, as the coat is my mother’s.

Every project is a prototype, which calls out for a second version avoiding the mistakes of the former. The trick is to give the prototypes away; then one has a legitimate excuse to make another—and one gains an (undeserved) reputation for generosity to boot. After the quick sunrise alarm clock various things happened, including a ’two week lockdown’ to build up capacity in the NHS, which turned into three months. Thus I was stuck in one part of London, and my fiancée in another, and the streets were patrolled by Dobermans with £10,000 fine notices stuck to their teeth. How to get from one side of London to the other?

Due to measures to combat the epidemic of bigamous marriages or something of the kind, we ended up having a wedding reception in the garden. Thus we needed tables, and benches, and things of the kind. Time to put the workbench to work.

Firstly there was a lorry:

Then there was a lot of wood:

The short pieces are legs for the benches; the longer will become benches and trestles (and will replace these horrible trestles I made earlier). But the OSB was even more of a nuisance, so that got sliced up first.

The first shot at a workbench sat dormant for a fair while. Meanwhile it got cold—very very cold. Then it got wet—very very wet. Then it got hot—very very hot. And how did my nice, carefully chosen unwarped 1" planks look after that? A pretty sorry state. Even the laminated legs had moved slightly (next time for lamination I need more glue). Then I discovered that I could get 6x2s from MKM building supplies. I rang to ask about stock and he checked—‘yes, I’ve got 3,500m in stock at the moment’. Madly I decided to take the trolley out again. Very madly, as MKM deliver for free, and if you plead with them they will select vaguely straight timber for you. Instead of which I lugged this lot home:

OpenFridge has been running the fridge since the first post, which apparently was in January. In that time:

• The fridge has been very cold (in fact so cold I increased the setpoint to 5 degrees and moved the sensor to the bottom)
• The freezer has been cold, as desired
• The controller reboots pretty frequently
• The controller sometimes loses the network connection and can’t allocate enough ram to recover it
• The controller occasionally latches up entirely, even with the software watchdog enabled, and refuses to respond to serial commands.

I speculate that this latter is caused either by 1. brown out/noise/bouncing from switching a relay (it almost always happens after switching the compressor off) or 2. noise on the lines causing the ESP32 to enter step/run debugging mode. I ‘fixed’ it by a. adding a 555-based hardware WDT and b. moving the relay board ground line to separate the grounds. Unfortunately, the RESET_CAUSE property is not very reliable (reproducible) so I can’t really get any metrics on how often this is triggering.

Hardware

So we have five mains circuits: the lamp, the fan, the heaters, the compressor, and the ‘superfreeze’ button, which I think just adds the starting coils permanently. The original controller only switches four of these on the board (the superfreeze is a manual switch), and uses triacs for all except the compressor, which has a 10A relay. Of course, that requires the controller to be attached to the AC neutral, which isn’t a great idea with exposed hardware like a prototype balanced on a fridge. So we’ll use relays for everything: three low-current relays, and two great big 15A monsters, all from the microwave control board.

We have a Hotpoint FFA52 fridge-freezer. It has previously given much hardship. It no longer works. Here is a graph of a non-working freezer:

I don’t mind a bit of swing in the temperature, but that’s all over the place. In the meantime the fridge compartment turned into a freezer, albeit not a very good one. Time to take it apart and see what the problem could be.

Cooling System

This fridge-freezer has one fan, two thermistors (one in each compartment), one heat exchange (at the top of the freezer compartment), a duct around the heat exchange/fan which causes air to be drawn from the bottom of the freezer compartment and blown out at the top, recirculating via the door, a ‘superfreeze’ button which causes it get colder quicker (or possibly just colder) and is to be used ‘when the ambient temperature is below 16 degrees or you want to freeze fresh food’ and should be used ‘only for 24 hours, but always if the ambient temperature is below 16 degrees’, a light (in the fridge compartment), a door switch (in the fridge compartment), an uncalibrated knob to set the fridge temperature, and a power indicator, which never comes on. Attached to heat exchange is a defrosting coil and a thermal fuse, and another defrosting coil is in the polystyrene insulation directly below the heat exchange and in the duct.