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Taking the Delonghi Magnifica Apart

Posted on January 21, 2009 by Rob in Blog, Interesting | Comments Off

The story starts off with me noticing that recently while pulling shots of espresso, the espresso machine has been getting slower at extracting the shots. I adjusted the grinder about 30% and that seem to have fixed the problem. Because the grinder is a conical burr grinder it shouldn’t get clogged. However, I wanted to take it apart to clean it and see how it all was put together. I didn’t get a chance to take the grinder apart because it had more parts than I wanted to deal with on a Sunday morning. I did however snaps some good pictures which you can see below.

This is the machine after the front door is opened. You can clearly see the carrier and its release tabs (red).

I have removed the carrier and the drip tray with the used espresso puck container and set it aside. As you can see, it gets pretty messy in there however it is easy to clean out.

Besides awfully messy wiring (came like this, i promise), there are two things to note in this picture. The first is in the middle of the machine you’ll notice the 15 bar pump which has a label on it. This pump is the main pump used for pulling shots. Then a bit lower and to the left is a large motor. This motor is what drives the carrier up and down. It is large because it is used to drive the carrier into the tamper in compress the grinds. It appears as though there is some mechanical advantage happening here but I didn’t determine how much.

Here we have the right side of the machine. On the top tucked underneath you’ll notice the very shiny aluminum block. This is the heater and serves two purposes. The water is heated here and the radiated heat is used to heat the shot glasses which are placed on top of the stainless steel plate. Also, on the bottom of the machine there is a small water filter that connects into the tubing from the water reservoir (not present in this picture). It’s nice to know they added such a simple yet potentially product-saving item. It’s incredible how many products out there cut corners in these areas. Sometimes it’s only one little item that was overlooked or vetoed by the accountant that kept it from receiving “excellent” reviews. I’m happy to state that this Delonghi Magnifica is not one of them and I have been thoroughly satisfied with it. On to more pictures…

This is the brew head where the magic happens. When the carrier comes up to this location it presses (tamps) the grinds and brews the coffee all at once (genius). The red o-ring is there because this brewing head actually slides down into the carrier. This provides the seal to hold in the very high pressures used when pulling espresso shots. See the next image for detail on this part of the carrier.

This picture is looking down into the top of the carrier. This is where the brewing head resides when pulling (pumping) a shot of espresso. At the bottom is the metal grate which acts as the filter. It keeps the grinds captive while allowing the espresso through.

This picture shows how the puck slapper scrapes the used espresso puck off into the bin. When you empty the pins the pucks are surprisingly very well intact and easy to dispose of. In the summer, we use them in the garden as fertilizer.

Lastly, we have the circuit board. Upon close inspection they’re using a microchip microcontroller and several mosfets for heater and motor control. With just a cursory glance the circuit board looks quite nice and well designed. My only gripe is the messy wiring seen on the rear of the machine. It’s so easy to throw in a few ties and makes all the difference during servicing and troubleshooting.

Inside the Delonghi Magnifica Espresso Machine

Posted on January 19, 2009 by Rob in Blog, Headline, Interesting | Leave a comment

So here we have a Delonghi Magnifica super automatic espresso machine. This is one beautiful piece of machinery. I’m not saying this because of its aesthetic characteristics but because of how well it performs. After using a manual machine with a blade-type grinder to make espresso every morning, upgrading to a super automatic is like a dream come true!

Many espresso/coffee purists would say that a super automatic machine is akin to taking a Geo Metro and putting tires from a Ferrari on it hoping for Ferrari-like performance. I disagree. When you consider the quality of the result combined with the time/hassle savings, it becomes a no-brainer.

Down to business… Check out this first video showing the basic brewing of a shot of espresso. It shows what a “good” shot should look like with the crema on top. I muted the sound as its rather uninteresting.

Next we have the video with the door open. Those clever guys over at Delonghi spared no expense when it comes to fault detection (door switch, water level, used espresso puck level, mineral buildup counter, etc). As a result, a paring knife was used to overide the door switch. I will go into more detail in the up coming days as to what does what.

Here is what’s happening in this video:

The carriage (black plastic with red tabs) is moving from its brewing location down to its home position. We also call this the dump position. This is the position where it dumps off any pucks of ground espresso. If you watch the video closely, you can see the flapper moving away and slapping the buck into the bin (there is no puck yet but if there was, that is what it’d do).

Now the carraige moves up to the grind location. The grinder will grind beans (after user selects serving size button) found in the hopper on the top of the machine. The grinds will fall out of the grinder and into the top of the carriage.

The carriage now moves up and to the right. When it does this you’ll notice after it stops, it moves slightly up again. It is actually compressing (tamping) the grinds into the carriage. Typically, on a manual machine this is done by hand with a tamper. Because this machine has a combined brewing head and tamper, it is able to stay at location after compressing the grinds to brew.The machine will immediately start the pump to begin the brew cycle. It does something called pre-brewing where by it wets the grinds down and waits a few seconds for them to saturate. This allows for a better shot of espresso. After the grinds are wetted it will execute the remainder of the extraction. In this video you’ll notice that the shot has an awefull lot of crema on top. I found it interesting myself how much more there was when the door was open and the espresso was falling straight into the glass instead of through the machine’s shoot. I believe I may have my grinder set too fine and will have to check into it.

After the extraction is complete, the carriage returns to the lower position and simulataneously ejects the puck of spent espresso grinds.

The carriage returns up to the grinder to wait for you to request another excellent shot (or 2) of espresso.