Today, Tije nearly finished the new Transparent Portafilter. When the sealant has hardened and some final polishing is done, it's ready for action.
Steps taken
The polished 'puck' is first covered with a transparent protective tape. Then the existing hole is drilled out to be much bigger, followed by the lathe cutting out a tiny sliver at a time from the inside out, widening the inside hole and slowly turning the 'puck' into a short 'bottomless basket' with an outside rim on the top and an inside rim on the bottom where the metal mesh bottom will be fitted.
Small disaster
Despite the utmost care and the tiniest steps taken with the two delicately sharp cutting tools made by Tije for the task of cutting out most of the bottom of the 'basket', at one point the lathe lost its grip on the basket which damaged the top rim a little, also leaving a deep scratch on the outside of the basket.
Finishing this prototype
Tije wanted to start making a new one right away but I voted to first finish this one. We have learned that this last cutting out of the bottom needs to be done by a drill, followed by careful filing. We might learn more as we move on and then, a next version can be produced even better.
Protective tape around the 'puck'
Cutting the excess tape
Puck in the lathe grips
Drilling out the inside hole
Transparency shows the drill at work
The hole must be widened to leave a strong walled basket
Tije at work
Cutting, tiny step by tiny step
Needs more widening
Next, the bottom needs to be cut out, leaving a little 'lip' to support the metal sieve
Lining out the cutting tool
Polishing the inside of the wall
Wall is getting clearer
The bottom needs to go still
Tije filed out this cutting tool
Carefully cutting away
Tije at work
After the little disaster of the lathe losing grip, Tije cuts the rest using the sharp disc
Making the rim more even
Basket sitting on the sieve for size
Making the sieve fit exactly
Measuring
The sieve will fit now
Getting out the sticky goo
Goo to keep the sieve in place and seal off the rim
Goo to stick the transparent basket in the bottom of the bottomless metal basket
(also see Daily Coffee News feature ) Tije designed and made the following structure for a tiny and cheap fluid bed roaster, to which Jan van der Weel added the Arduino parts, electronics and programming: Sketch by Tije de Jong Jan sourced a very cheap blower (€ 11) to start with, Tije developed and constructed the mechanics, Jan built together and programmed the TC4 / SSR electronics. On his blog, Jan will specify exactly how the TC4 part is combined and programmed and I will copy these details into this blog entry, just as Jan will use this video in his blog. We did a few test roasts to make sure it works at all and it does. Towards the end, the first roast tended to get a flat BT line and airflow was slightly decreased. 200g seems max load of green beans. Second roast a little more power was given to the heater. Next we will try the Background Roast driven by the PID software of Artisan. A week later, with updated software that works better to change the...
Peter van der Weerd fom KAFKO gave my Rocket Giotto a cleanup and upgrade. It was a great chance to see the intricacies of the E61 brew group inside out and to see some of the details and little tricks one should remember when doing it oneself. Peter encourages people learning about these basic service procedures and when he sends out a set of all necessary parts, he includes a diagram and some instructions. Plus his phone number, because he is available for advice in case someone is surrounded by parts and doesn't know what to do next... What we (well actually he) did: E61 Cleanup, changing seals, removing scale Vibration pump replacement (newer one less noisy), new metal connection Anti-vac upgrade, startup release of water/steam out the front panel now Boiler insulation removed (better looking, better cup heating) Below, lots of pictures telling the story and some brief comments. There's other web pages with extensive info on the E61, like this excellent page (th...
100% to 0% The Rocket Giotto espresso machine at my girl friend's place uses water from a Brita filter . This filter has a timer that counts down from "100%" to zero over a number of weeks but that time span is totally unrelated to the actual use of the filter so it's useless as a reminder to change the filter cartridge for a fresh one. Unpredictable I reset the timer a few times before replacing the filter but then I mostly forget how often I have reset it and I take out a new cartridge when I start to feel worried about the water hardness, which is subjective and unpredictable. Brita themselves suggest replacing it every two months or after every 40 gallons of water taken from the pitcher although local water hardness may vary greatly and thus influence the life span of a filter cartridge. So that's not a great help either. It would be nice if Brita supplied a test kit to see when the water quality delivered by the filter is deteriorating. Predicting ...
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