This year I have plated several parts of my coffee machine with zinc to prevent corrosion. This turns out to be surprisingly easy to do at home and I found I already had all the components I needed.
I have plated the bracket which holds the steam boiler in my Gaggia Baby Twin, the bolts which hold the boiler together and the bracket which holds the thermal fuse in place and also acts as a terminal for the earth wire onto the boiler.
Let’s suppose you’ve figured out a fab design for a temperature probe that could be mounted anywhere on the Gaggia boiler. What is the best placement for your probe? Two obvious considerations spring to mind:
- Ideally the probe will reflect the water temperature well (rather than, say, always be colder than the water by some amount that is affected by ambient temperature or always hotter because it is more affected by the heating elements than the water).
- Ideally the probe will respond very quickly to changes in temperature.
I have not found it easy to design a cheap and reliable temperature probe which can easily be mounted on the Gaggia boiler. If you have a simple solution, I would love to hear about it.
Here I document my present probe design and an idea I have just had which is really simple and obvious to me since I built a 3D printer but wasn’t before.
There are also some notes at the end about types of devices which could be used for temperature probes and how to use them with the rev2 board.
The short version: Our present way of dealing with COVID-19 is insane. Of the only two sane approaches, both require intolerable levels of restrictions over a sustained period. In one approach these gradually scale back and COVID-19 kills a significant fraction of a year’s worth of normal deaths over about 6 months. In the other, the intolerable restrictions remain for an unknown period of more than 6 months and possibly years but COVID-19 kills almost no one. I would love to be wrong about this, but I don’t think I am. The choice before us sucks. Take your pick.
The longer explanation…
Some time back I lived near Durham where the water is blissfully soft. Five years of sparkly clean kettle and coffee machine that just don’t scale up! Since moving to a harder water area, I have often wanted to recapture those halcyon days. And now I think I may have…
I’ll spare you the long sob story about fruitless googling for simple effective answers to scale and jump to the solution I am now trialing: citric acid.
As expected, the UK government announced yesterday that the present “lockdown” restrictions would remain for the present. Nonetheless, it is becoming clear that now is a time when critical decisions must be made. No one can be certain when we will reach the “peak” (and we won’t know it was the peak for certain until afterwards anyway) but it is clearly some time around now.
At this point it is vital that we know what kind of endgame we wish to target with COVID-19. We will make dramatically different choices depending on this choice. And I suspect the best endgame may not be the one we are drifting towards.
A number of Christians have said to me that God will keep us safe from COVID-19 and that we can treat the government’s advice lightly. I want to be very clear in saying that this is unwise, theologically incorrect and socially irresponsible. Continue reading
One of the saddest sounds in the world is the change in tone of the water pump as the water runs dry half way through a shot. There’s no real rescuing this situation. It’s go ahead with a sub-par cup of coffee or start again. Not only is that a wasted 40p of coffee beans but, worse, it dishonours the farmers, roasters and everyone else who has put so much effort into bringing such a wonderful flavour to you from the far reaches of the planet. So, what is needed is a water level meter that can warn when the reservoir is getting low. Continue reading
When modding a coffee machine, it is easy to overlook questions around just how to connect up the wiring. The space the wiring occupies can be very hot. Just the air can easily be over 70°C and if the wire touches the boiler itself, that can be well over 100°C. Some wires also have to carry fairly large currents and mains voltage. The large currents cause extra heating and the large currents and voltages both cause electromagnetic interference.
Here are some wiring tricks I have learnt over the years. Continue reading
I have struggled for years to find a good way to mount the flow meter on my pimped Gaggia Baby Class. Eventually, when I bought an old Gaggia Baby Twin, I had a look a the metal bracket Gaggia uses and that immediately gave me an idea. An old PC expansion card blanking plate, bent over, a notch filed on the end and a cable tie. A little bit of silicone glue for stability and viola! Continue reading