HB wrote:Hard to say, it depends on which double boiler and which HX under consideration. Given the choice between an Elektra A3 and Expobar Brewtus, which would you choose?

Neither probably - although I've not used either of them, so a view from someone who's owned both would be welcome.

I'd probably choose a La spaziale S1, which is a much fairer comparison based on the price of the A3 (but still cheaper I think).

Or, if price isn't a valid comparator, a La Marzocco GS3 once they get the (alleged) build quality issues sorted out.

I'd be happy with an Elektra barlume though (if only as a trophy - probably not to use).

ntwkgestapo wrote:I too have been agonizing ...First look was @ HX machines ...Then I began to RE-Read ...

... I AM working on a design for a "home" system. Dual boilers, PID temp and pressure control (both for brew and steam AND ... as well as INTRAShot control...with the ability to... etc...

Wow ntwkgestapo! Somewhat reminds me of the quest for the Holy Grail - if only I were religious.

Your project sounds very ambitious, especially as it started with the intention to upgrade your starbucks thingy

May I recommend you to try an Europiccola while progressing with your project simply to discover a world of coffee which isnt all about numbers and specs - just like a good photographer will still be capable to do wonderful pictures with a 2$cam...

Then I'd invite you to design my personal 2 boiler, PIDed and pressure controlled lever machine with saturated grouphead that would be able to keep steady temperature while being supplied by fresh cool water, using less energy and time to heat up than the current pavoni. would be nice if it showed the pressure in the grouphead too.

Enjoy your project and keep us updated please! any sketches yet?

keepitsimple wrote:Neither probably - although I've not used either of them, so a view from someone who's owned both would be welcome.

And therein lies my point - it's never as simple as "a double boiler espresso machine is THE answer." In terms of superior espresso, I would pick the A3 over the Brewtus or the S1, but then there's practical matters like size, cost, heat up time, plumbing requirements, etc. In the end, all I can do is hope that the Bench research and buyer's guides provide enough information from multiple viewpoints for readers to make an informed decision.

Not yet! Actually still doing the basics.... I've already figured out the CTQs (the Critical TO Quality specs, in Six Sigma Speak!) and am almost finished with determining the "Fault" conditions and how to handle them (i.e. temperature is above/below target for this point within the shot, brew group head at to high/to low temp, boiler temperature continues to rise even tho I've SUPPOSEDLY turned off the heater [and I'm not speaking of hysteresis or overshoot here, I'm saying the boiler heater apparently DIDN'T turn off!], motor continues to run after I've told it to stop, etc.) Even working on catastrophic failure of the system and how to handle THAT! I come from an industrial control environment where faults can KILL people, so I have a tendency to be a bit anal on this stuff! Physical design will shake out over the next little while. I'm thinking of doing both a dual boiler system and a single boiler, dual use design altho I'll probably only build one... SOME of the CTQs for this are tight temp control (to a real world 0.5 degree C as doing a REAL 0.1C system would require lab-quality equipment of an EXTREME cost nature!), tight brew pressure control (0.1bar should be obtainable), the ability to simulate HX-Hump temp profiles, lever pressure profiles, etc. There's more to it than what I've mentioned and once I've got the document closer to being finished I have every intention of putting it up for HBer's to critique (I'll ask them to be gentle and hope they don't gut me! ) There will be proposed physical design details and a first shot at a user interface so I expect a LOT of discussion around it once I'm ready!

HB wrote:And therein lies my point - it's never as simple as "a double boiler espresso machine is THE answer." In terms of superior espresso, I would pick the A3 over the Brewtus or the S1, but then there's practical matters like size, cost, heat up time, plumbing requirements, etc. In the end, all I can do is hope that the Bench research and buyer's guides provide enough information from multiple viewpoints for readers to make an informed decision.

Well, forums such as this wouldn't be nearly as widely read if there were to be a simple consistent answer