donderdag 13 augustus 2015

Londinium L1-P seals, sleeve, and a helpful tool from Stephen Sweeney

First a few images of a typical group piston seals change done on the piston out of the Londinium L1 which is identical to the one on the L1-P:






For replacement seals I got two slightly different sets from Peter at www.kafko.nl
In the picture below you see the three on the left (Astoria type) are just a bit thinner than the Cimbali type on the right. I decided to use the Astoria seals which are more flexible. They are very much like the ones I am used to on the Londinium machines.
 
When I took out the piston of the L1-P, I also took out the sleeve so I could see the inside recess:

The inside of the group with the sleeve out:

Re-inserting the sleeve after cleaning and lubricating:

It goes in a little bit  deeper than this:

Then on to the seals. I use a little spoon without any sharp edges to take off the old seals:

I could use the same spoon or an allen key to put the new seals back on but I took the opportunity to try out a tool that Stephen Sweeney made. This makes it extremely easy to slip on a seal. Just lubricate the shaft well, slide it over to the place on the piston you want the seal to end up in, and smoothly slip the seal over the shaft into the groove.

 Second seal on:
 Third, and done! Thanks Stephen!
Similar tools have been developed for the Olympia Cremina in the past. This picture is shown on
http://www.home-barista.com/levers/olympia-cremina-piston-service-tools-t3580.html :


The picture below is from Reiss Gunson, who had a Cremina years ago:
I'd say anyone with patience and a careful approach can easily change the seals with an allen key but if one is a bit nervous about damaging any seal, the tool makes it a complete breeze.

woensdag 12 augustus 2015

Compak R120, Londinium & Acaia espresso routine

Pulling an espresso from 15.1g of Los Lajones beans from the Panama farm of Graciano Cruz, imported by Kees Kraakman of Stadsbranderij Noord. Scales used: Acaia Pearl & Lunar. Grinder: R120 by Compak. Tamper by Londinium, lever espresso machine L1-P by Londinium.

iPhone used for filming.


donderdag 6 augustus 2015

Compak R120 & vintage theatre spotlight

Before going to sleep I noticed how the vintage spotlight that Tije fixed for me lights the huge R120 grinder very well when all other lights have been shut off already. I took out my camera and made this picture (ISO12800, so dim was the room!)

Thank you Tije! Below is a video of how he made me the coupling piece that enabled the vintage theatre spotlight to fit on the expandable bracket, also from an old theatre but of a slightly different size.


woensdag 5 augustus 2015

Shake, Not Stir: Tije's Roaster Shaker for Coffee Beans

Over the past months, Tije has been testing out several concepts for a fluid bed roaster that will be very similar to my Fracino Roastilino but with a larger capacity.  One example is shown here:

A problem in this setup is the high speed of the cheap blower we are using. The blower is so powerful that it cools the heating element rather than heat the beans and it tends to blow beans all over the place instead of just "stirring" them around. We actually need a blower that has less speed with more static pressure and we're currently looking at an Multi Stage MS8 Backward Curved, Single Inlet Centrifugal Fan from Air Control Industries.

Taking a break from this R&D which is more time consuming than we anticipated, Tije has worked on an idea of his own, using very basic materials which most everyone has in the household somewhere.

Tije let go of the idea to agitate the beans by a powerful air flow and he also discarded the "rolling drum" concept which has been used in most classic roasters so far. He tried stirring the beans but found that this hard to do automatically. He used the motion of a jigsaw to shake a kitchen sieve filled with beans and he took the heat from a simple paint stripper:


In the next version, a hood will help catch chaff and smoke and a more effective cooling system will be tested too. We will be monitoring the bean temperature using a probe and the Artisan Roast Logging software.

The initial results are very promising. It might become a very minimalistic roaster, combining high tech with the least amount of sophisticated hardware.


donderdag 30 juli 2015

Pop your corn in a coffee roaster

If you search Google for roasting coffee in a popcorn maker you get hundreds of suggestions but there is very little about popping corn in a coffee roaster so I set out to try:


It's very easy and it could be done faster too I think. The size increase is spectacular: I can load 220g of green coffee beans but I need to keep the dose of corn to 30g or the popped volume gets way too big for the glass mug.

woensdag 29 juli 2015

Amsterdam Coffee: Bike to Cup

Moyee Coffee, a "fair chain" coffee trader in Amsterdam sent me an email about a new service they provide for people who urgently need a fresh pack of beans roasted in Africa. They arrange free delivery by bicycle anywhere in Amsterdam.

I like it how their concept of an international enterprise also has a very local focus. Moyee is working to reward local African farmers who are enabled to ship their beans roasted and ready and now their supply chain is adding a delivery service on the other extreme end, to the front door of their customers.


Moyee is a very young and hip enterprise and it shows in the closing words of their mailing: "Veel liefs" -- in English that would be something like "Sweet love".

It communicates to me that I might be way too old for them. "Sweet love" is something that 17 year old girls write to each other in whatever social media app is currently "in". It's also used by 40 year old Uggs women who dress in tight stone washed ripped jeans like 17 year olds but I do not fit into that category either. 

If I would close an email to a business partner with "Sweet love" I would probably be ignored really fast and if I sent something like that to a young female acquaintance I could get in serious trouble. 

Still I was interested in the idea and I downloaded the TringTring app for local food delivery by bicycle couriers:


It promises some wonderful alternatives to have precious fresh food delivered to the home or office. The good life brought to you in the most sustainable way possible, by bicycle.

I have never visited the White Label Coffee shop even though they just a few blocks from my home. I heard they know their business and two of their baristas even won championships in Aeropress. So this was a fine opportunity to have some of their beans zipped over to me.

Registering the app was easy, the PayPal option is not yet ready but the Credit Card option was quite nifty: take a picture of your card, enter the expiry date and security code, done. 

I selected some Rwandan beans, Bourbon type, grown at 2100-2300m altitude which White Label have roasted themselves after buying from ThisSideUp coffee traders.

A little later I received a text message announcing the delivery. The guy handed me a bag with receipts, checked a code from my text message to make sure the right person had received the order (very clever detail) and left for his next delivery:

Thijs from TringTring waving goodbye
Below are a few pictures. The beans are roasted very light as is the fashion these days, so it's best  to go along and also updose as is done by many baristas today. I also want to try to mix/blend these fruity beans with Brazil Mogliana beans that I recently roasted.

The shot below was made using a 17g dose in the 15g VST basket, extracting 33g of espresso in 29 seconds, so I could grind a little finer yet.



Bag as delivered, receipts attached


Using the Acaia Lunar scale to weigh beans for a 15.06g single dose grind on the Compak R120 grinder






zondag 26 juli 2015

"Zero" tracking on the Acaia scale for coffee

[More photos and videos about the acaia lunar here]




Mr Rex Tseng from Acaia explained some details to me about the "zero tracking" mechanism in their scales.

Initially I had no idea what this was about. One assumes that a scale shows the weight, period. For coffee, one ideally wants a scale with 0.1g precision so the optional 0.01g resolution of the Lunar is especially pleasant.

If there is no weight on the scale and it displays 0.00g then a number of circumstances can give the scale the impression there's some minute weight on or off it. At this rate of sensitivity, even blowing your nose near to the scale can make the scale sense the air movement and translate this into a temporary "weight".

But even though one wants the scale to ignore such tiny differences at 0.00g it is still necessary to display all minute changes when one is actually weighing off something. For instance, when measuring off an exact 14.00g of dose into a filter basket, one does want to see the numbers reflect the tiniest pinch of extra grinds added or taken off the dose.


The video above shows my checking this out and below is a quote from the message by Rex Tseng:


The tracking option in the settings menu is a technology for acaia scales to remain stable at zero. 

Here are some backgrounds of the weighing definitions:

min = minimum starting weight
d = minimum increment of the scale
max = maximum weighing capacity
e = margin of error

for the acaia Pearl (1.74)
min = 0.3g
d = 0.1g
max = 2000g


For all the scales / balances, the weighing result will drift over time due to many different reasons. The ‘zero’ point (0.0g) will drift, especially over a span of time. It could be heating from the electronics, can be the ambient noise, can be the room temperature changes, or simply because of a cheap / poor load cell sensor.

The zero tracking mechanism in acaia is designed so that it will track the zero point within certain criteria to allow the zero point to remain stable over the time span. For example, 

When the zero tracking range is set at 2d (2*0.1g = 0.2g) in the option menu:

If the zero point drifts from 0.0g to 0.1g (it can be a drift or putting a weight of 0.1g on the Pearl), it will be ‘tracked’ and the scale will read 0.0g. 

If the zero point drifts from 0.0g to 0.3g (it can be a weight of 0.3g on the Pearl), it will not be tracked and deemed as an object on the Pearl. 

This zero tracking allow the Pearl to perform long time consistency for the starting zero point. 

The zero tracking mechanism will NOT operate if there is any weight on top of it, it only operates around 0.0g. So if you put a 10g weight on the Pearl, and add 0.2g on the Pearl, it will show 10.2g. 

If you try with other low-end scale in the market, you will notice that if you turn on the scale for period of time without weighing, it will read from 0.0g to any numbers like +- 0.5. That’s also one reason low-end scales need to have an auto off set at 1 minute, in order not to show its unstableness. Another reason for low-end scale to set the min = 2g  (even though d=0.1g), is also because they were not able track the zero point, so they will ignore anything below 2g at zero point. 

So if you want to see the most responsive weighing result, you can make the zero tracking to 1d or OFF, the trade off will be a less stable zero point.