Jack of All Trades

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. [Read More]

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. [Read More]

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. [Read More]

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). [Read More]

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. [Read More]

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. [Read More]

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. [Read More]

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. [Read More]

This post is largely a log so I remember how to do it next time, but if anyone else has a bunch of scans to convert, read on… Background Frequently in academia—and probably in much of the modern world—one has to handle things which began life as books, hit the glass of a scanner, and became pdfs. Scanning is hard, and unless one has a lot of patience, the resulting pdfs are generally pretty all over the place: sometimes pages are upside down, frequently the book (which was not made to lie flat) does not want to flatten on the glass, and often the scanner has simply picked a nearby standard page size. [Read More]

Somebody has bent the toaster. It shouldn’t be looking like this: It should be looking rather like this: Oh well. It’s only mild steel and it bends easily. Some springs got out of place too, but it’s easy enough to ping them all back, particularly with the unbent side for comparison. The hard thing is normally taking toasters apart—cheapy ones are frequently held together with bent metal tabs, which sheer if you try to unbend them—and of course it’s always messy. [Read More]