I had taken Ursula into work for a couple of days (and made some new friends), but brought her back home this weekend for some maintenance and a thorough disassembly. I had wanted to check the seals, something I hadn't been able to do earlier in the week, and get the cylinder and piston thoroughly cleaned and everything that needed lubing properly greased down.

Ursula is nowhere near as easy to work on as the earlier Caravels. Dr. Salati's ideas about a machine that is easily serviceable by the owner seem to have faded as the design changed hands. In order to remove the piston from the group head, you must completely remove the kettle and since the heater is attached to the bottom of the kettle, and the thermostat is attached to the side of the kettle and to the indicator light on the front of the case, you have to undo four machine screws that hold the plastic kettle surround in place, then four screws that hold on the front plate that covers the cylinder, lift the kettle slightly so you can unhook some wire terminals, then remove the kettle so you can spring out the lever arms so you can pull the kettle out to finish removing the front plate, which is what normally keeps the pin that secures the piston assembly in the cylinder in place. Once the front plate is removed, you simply slide the pin out and pull out the piston assembly.







The piston and seals are identical to the Caravel Type II, with a hollow piston and o-ring seals in the walls of the cylinder and the tiny o-ring sealing the piston on the downstroke and letting air out when drawing water from the kettle (and also letting air in on the upstroke, which is why Fellini moves and multiple pulls have less tendency to disturb the puck on the Caravel - there is little to no vacuum created in the cylinder on the upstroke because the small o-ring unseals as soon as the piston starts getting pulled up). All the seals were as clean and flexible as new, so I applied a little Dow 111 and put them back in place. I guess the spare set I ordered from Orphan stays in the supply drawer against future need.






Cylinder bottom before cleaning


Cylinder bottom after cleaning


Cylinder top before cleaning


Cylinder Top after cleaning.

And in parting, if I had a camera with better depth of field than the point and shoot I was taking this with, I would have pulled a shot on the other Caravel into one of my 2 oz. Bodum borosilicate espresso glasses, done a little creative lighting, put the shot at the far end of the cylinder, and entered it in the barista bling contest.

George, looks like you got a fair dinkum deal on Ursula.

He certainly did. That looks like a new machine, there!

It looks functionally great. It would be interesting to know the history of the design- was the group design bought from Caravel, and the box added by Zerowatt?

There is no doubt that the Caravel piston design is a simple, elegant solution to one of man's greatest mysteries (i.e., how to best extract the elixir of life from 14g of roasted coffee beans). On that front, I received yesterday an envelop from PA containing three bags of roasted and posted CF Ambrosia, courtesy of hperry! I had to squeeze in the first shot on the PV last night, and it was heaven, along with this AM's PV cappuccino. but I'm at work all day today, where the Caravel usually whiles away her lonely weekends. This weekend she will not be lonely, being generously supplied with Ambrosia upon which to test her skills, while I attempt to get a proposal written.

We've been accompanied by Perlman's redition of Mozart's violin concerto no. 5 ("Turkish"), which I intend to someday put to a Caravel video. I found this version, by the lovely Janine Jansen, on youtube:

http://www.youtube.com/watch?v=5Q...fI&feature=related

When one is aspiring to new heights, it always pays to be in the company of giants.


PC

oh, and the second movement, by Anne-Sophie Mutter. Impossible!
http://www.youtube.com/watch?v=xx...sU&feature=related

Try pulling a shot on your lever machine with her accompaniment.

and my favorite movement:
http://www.youtube.com/watch?v=td...xt_from=PL&index=2

Oh, yes! Lever and Mozart!

peacecup wrote:It looks functionally great. It would be interesting to know the history of the design- was the group design bought from Caravel, and the box added by Zerowatt?

And just who was Giubel S.R.L.? Their name on the manual, with an address in Correggio, adds another level of mystery. Assuming that VAM, who apparently made the heating element and had their brand on the very first units, then Arrarex, both based in Milan, manufactured the 'classic' Caravels, and that Arrarex manufactured the Little, which appears to have morphed into the Ursula somewhere along the way, how did a company in Correggio (which is a small city between Parma and Modena) end up manufacturing it and somehow the unit becoming the Zerowatt C.A. 709 (nowhere near as cool a name as Caravel or Ursula, if you ask me)? Was Giubel bought out by Zerowatt?

There is no doubt that the Caravel piston design is a simple, elegant solution to one of man's greatest mysteries (i.e., how to best extract the elixir of life from 14g of roasted coffee beans)...

The more I use it, the more I appreciate the sheer elegance of the design. It hadn't occurred to me before last night how the piston design solves the problem of vacuum disturbing the puck on a multiple pull. I may next pick up a stovetop steamer, just so I can make the occasional macchiato or cappa, but for pure espresso, I think you have to go a long way to beat Clarabelle or Ursula once you get to know them.

The only weakness of the machines as they were manufactured is the thermostatic control. On both of mine, there's about a 20°F (11°C) drop after the thermostat turns the heating element off before it turns it back on. The non-adjustable thermostat on Ursula switches off at 204°F, which seems pretty much where you want the kettle water to be, but the window for pulling a shot at a good temp is not large before you have to wait for it to cycle again. I see a PID in Ursula's future, I do. Maybe in Clarabelle's, as well, but with the classic design, you can get the heating element to turn back on before it's dropped too far by futzing with the thermostat knob.

Addendum: Doing a little research with Ursula's heater and thermostat this morning. The heater switches off at 204°F, and residual heat coasts it up to 208°F. It then cools down to 183°F before the heater switches back on. It takes 1:58 for the 500 watt heater to get the kettle from 183°F to 204°F, which is not bad. But it takes over 14:00 for the kettle to cool sufficiently for the heater to cycle back on, most of which time the water in the kettle is far too cool for pulling a shot. Personally, I don't need 3 doubles in quick succession (and since it takes me about 2 minutes to grind 14 grams on either of the hand grinders here at home, that would be a challenge in the first place), but if my timing is just off, and I decide I want an espresso just as the temp dips below what's suitable, it's a long 15 minute wait until I can pull one.

Addendum: Doing a little research with Ursula's heater and thermostat this morning. The heater switches off at 204°F, and residual heat coasts it up to 208°F. It then cools down to 183°F before the heater switches back on. It takes 1:58 for the 500 watt heater to get the kettle from 183°F to 204°F, which is not bad. But it takes over 14:00 for the kettle to cool sufficiently for the heater to cycle back on, most of which time the water in the kettle is far too cool for pulling a shot. Personally, I don't need 3 doubles in quick succession (and since it takes me about 2 minutes to grind 14 grams on either of the hand grinders here at home, that would be a challenge in the first place), but if my timing is just off, and I decide I want an espresso just as the temp dips below what's suitable, it's a long 15 minute wait until I can pull one.

George, congratulations on your new addition to the coffee family! Perhaps, the use of an immersion heater could aid in maintaining the water temp for multiple shots. As Ursula's heating cycle ends, insert the immersion heater and turn it on to help the water maintain the temp. When you are finished pulling your shots, unplug or turn of the immersion heater before removing it from Ursula (otherwise the immersion heater could stop working, permanently).
Anyway, just a thought...

Steve in Ft. Worth

Hello George- I just managed to source one of these- it looks exactly the same as yours, I was surprised by the quality of it- very solidly made. In pictures it looks plasticky- but in reality much nicer. Shame the cylinder cannot be removed easily though...

Mine is also in great condition and is working very well-

Except: the thermostat never kicks in- the kettle gets to a boil but just keeps rolling along. The light on the front never comes on.

I was wondering- how hard is it to access the thermostat? And is it adjustable?

The machine really works fine without this- just switch it off when it reaches a boil. But I would like to get it functioning perfectly.