Talk about a post explosion! I will try to get all your questions later tonight, my son's 7th birthday is today so I am preoccupied for most of the day.

timo888 wrote:Whenever opportunity for another measurement presents itself: what is the thread pitch of the retaining screw that holds the dispersion screen in place, and the thread pitch of the allens screws that hold the dispersion block in place?

The dispersion block was said to be aluminum. Are the screws stainless steel?

Regards
Timo

I do not have a pitch gauge to measure these.

I have disassembled a good part of the machine to see how things work. All the fasteners have been stainless steel, I can not positively recall if the group to boiler bolts are stainless or zinc plated but I believe they were stainless with nylon inserts on bronze stud. You can see the attachment points back on page 3 where I took the group apart.

There is extensive use of stainless in the machine, I believe the heat exchanger is also made of stainless tubing as is the base, boiler, boiler covers, steam wand and even the 'froth aid' tip is mostly stainless with nylon/plastic insert.

hbuchtel wrote:(from Why lever shots are better: A Theory)

Dan and Dave, both of you have a lot of experience with 58mm baskets and HX machines, could this (or one of these) partially explain your better results with the Achille as compared to the Factory, Microcasa a Leva, and Cremina?

It is probably safe to say that most people who make espresso would find a 58mm basket easier to work with then some of the other sizes often found on lever machines.

Henry

I am sure the basket size and heat exchanger operation add to the machine's cup qualities. The Achille operates fundamentally different than any of the machines you mention.

Before the Achille visited me I was perfectly happy with the deep toned shots I got from my Factory. I have become accustom to the buttery mouthfeel of the Achille as well as the cleaner, more complex cup it brings to the table. I can pick out flavors and notice nuances that the Factory was unable to produce.

I would liken the difference between a Silvia and La Marzocco. Many people are perfectly happy with the cup that the Silvia produces. It produces a cup that is unique to that machine. A La Marzocco produces a different cup. I will not say it is better than a Silvia, but it is different than a Silvia. Which cup you prefer is dictated by your personal preference.

The Factory (La Pavoni) does not necessarily make a bad shot, but a different shot than the Achille. My personal preference, I am enjoying the shots made from the Achille more than the deep mono toned shots I get from my Factory.

I try not to say that machine A makes a better cup than machine B, but rather machine A produces these cup characteristics and machine B produces another. Then it is up to you to decide if you prefer A or B. Taste is to personal and objective to debate, what I find wonderful you may find repulsive. If everyone enjoyed the same set of flavors, the world would only need one roaster and one machine.

hperry wrote:But, with the considerable difference that you are not limited to pulling shots 2, 3 and (perhaps) 4 to get a good shot. Your excellent review suggests that the Achille may solve most of the common problems associated with small levers. I personally would prefer that it was spring loaded for consistency, but that's a relatively minor quibble and probably a matter of preference.

One of the most defining characteristics of the Achille is it lack of overheating. For years that has been a sore spot for home lever machines. The Achille will eventually overheat. In my testing, after 10 hours of idle on time I had problems getting the group to cool. I could still pull shots from it but they had a distinctive 'to hot' taste. I doubt Gaggia intended for the machine to run 24/7 but I regularly run it for 5 hour intervals. On in the morning and off after lunch, then back on around dinner and off for the night.

Dan and I have both commented about the ability to pull many back to back shots with no heat issues. When Karl and I get together to do some machine comparisons, this will be one of the limiting factors. We will only be able to get a handful of shots out of each machine for the day because they all overheat. The Achille will perceivably bang out shots as long as your arm holds out.

timo888 wrote:Another request please: a close-up pic of the upper side of the dispersion block from whoever has their machine apart next.

Regards
Timo

I went through my photo archives but do not see a photo of the back. Is there some particular feature you are looking for?

timo888 wrote:How does the Achille fare on shots with the single basket?
Regards
Timo

I knew someone would eventually ask that. I tried pulling some singles but had issues with the dose. It is very easy to overfill the basket. I was scraping the puck against the shower screen on most of my shots and a few would not even lock into the group. The two or so I did manage to pull were very acidic compared to the double using the same blend.

I will try pulling some more singles today. You can not fill the basket to the top and level the grounds like you would a double. You have to dose to a small pile in the center and tamp it out based on my preliminary meltdown shots. A single lever pull should be plenty for a single shot, maybe even too much depending on the blend.

cannonfodder wrote:I do not have a pitch gauge to measure these.

I have disassembled a good part of the machine to see how things work. All the fasteners have been stainless steel, I can not positively recall if the group to boiler bolts are stainless or zinc plated but I believe they were stainless with nylon inserts on bronze stud. You can see the attachment points back on page 3 where I took the group apart.

There is extensive use of stainless in the machine, I believe the heat exchanger is also made of stainless tubing as is the base, boiler, boiler covers, steam wand and even the 'froth aid' tip is mostly stainless with nylon/plastic insert.

The reason I ask.... the dispersion screen retainer screw will be removed relatively frequently and won't have a chance to freeze up. The allen screws that hold the dispersion block in place, on the other hand, will be loosened relatively infrequently. I was wondering what thread pitch the Gaggia engineers chose, to meet those different conditions. The minutiae are fun (for some of us).

Regards
Timo

cannonfodder wrote:I went through my photo archives but do not see a photo of the back. Is there some particular feature you are looking for?

I wanted to see if there's a tube on the dispersion block that fits into the hole in the group block, or if it's simply two holes that line up.

Regards
Timo

As I recall, the water exit from the group does not mate up with a hole on the dispersion block. It simply spreads across the top face airspace (very small airspace) and then out the 4 dispersion block exit holes and onto the shower screen. Next time it pull it to clean I will take a photo. You can see the water exit hole on the group a few pages back on the water flow diagram, the exit hole is circled in red.

I played with singles for a day. I had the same issues as before with an overdose tendency. It took me a few shots to get it dialed back in. I kept getting a bitter cup but I believe that was due to the puck scraping the shower screen and causing channeling problems. I kept getting pale Illy crema.

I did manage to get it dialed in and forced myself to short dose and pay particular attention to the level/tamp. You know when you get it right just based on the crema color. I was using the tail end of some Ambrosia from Caffe Fresco, very tasty even at the end of its life cycle. It pulls all crema just like the double does. I get a little brighter cup than I do from the double but it still retains that buttery mouth feel and velvet soft crema. Here is a photo of a double pulled with Ambrosia and a single. They are very similar in appearance and taste with the exception of a little more acidic cup with the single.

Double shot Ambrosia


Single shot Ambrosia
Just for fun I pulled a single and turned it into a macchiato. Yes, go ahead and laugh but you try to pour some latte art in a 2oz cup. It was darn tasty.