Olympia Cremina Temperature Study, Part 4

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naked-portafilter
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Postby naked-portafilter » Jun 16, 2015, 4:32 pm

Hi there,

This is just a first post (an invitation for brainstorming) for measuring/comparing the temperature behavior of different Cremina models.

The first one in the row is an original 1974 Cremina without thermal break gasket, the second one is from the year 1976 with the thermal break gasket (this is the only difference between the two) and the red one is the recent model.

Last week I visited the factory in Glarus and Mr. Schätti and Mr. Sagehorn offered me two groups for the measurements. They are full functional with minor optical damages. Ideal for such experiments.

It would be nice to study the pressure behaviour/profile of the small levers as well (chamber).

I would be happy about your ideas regarding the measurements.

As I wrote already this is just a "kick off post", I'm planning to visit the company where I buy the thermocouples for ideas for properly/exactly made measurements and and I'd like to buy a 4 Channel temperature logger for that fun. I think and hope I can start with it in July.

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Feel free to comment and discuss this topic!

Thanks

Gábor

mathof

Postby mathof » Jun 16, 2015, 5:00 pm

I look forward to your results.

Matt

OldNuc

Postby OldNuc » Jun 16, 2015, 5:55 pm

Yes, this could be very interesting.

cpreston

Postby cpreston » Jun 16, 2015, 9:14 pm

Where are you planning to put the temp sensor on the group? FWIW I have mine near the bottom of the bell where it starts to flare out, and towards the rear.

I have been finding by taste that I like to run group temps hotter and boiler pressures higher than Tekomino did, for some reason. 2009 machine.

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espressme

Postby espressme » Jun 16, 2015, 11:13 pm

cpreston wrote:Where are you planning to put the temp sensor on the group? FWIW I have mine near the bottom of the bell where it starts to flare out, and towards the rear.
I have been finding by taste that I like to run group temps hotter and boiler pressures higher than Tekomino did, for some reason. 2009 machine.

87 Cremina, I like hotter for my brewing also. I steam first and then drop the shot into the milk.
~Richard
richard penney LMWDP #090,

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naked-portafilter
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Postby naked-portafilter » Jun 17, 2015, 3:18 pm

Thanks for your comments. I was wondering if it has any sense to make another (a new) part about this topic, If there is any interest? Seemingly yes. The new aspect is that I can measure now 3 different models and the additional groupheads which could be - if it makes sense - even drilled to get to spots which haven't been measured so far.

cpreston wrote:Where are you planning to put the temp sensor on the group? FWIW I have mine near the bottom of the bell where it starts to flare out, and towards the rear.


I will use the same spot I measured in the temp study, which is the same as the position you mentioned.

cpreston wrote:I have been finding by taste that I like to run group temps hotter and boiler pressures higher than Tekomino did, for some reason. 2009 machine.


Reason: tastes differ :-), I think at least. I don't want to say which group temperature works with wich boiler temperature best (for me) because this is subjective. All I want to get datas which could help small lever owners find their own optimum.

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naked-portafilter
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Postby naked-portafilter » Jun 24, 2015, 7:08 am

I will get in the following days the thermocouples and the 4 channel logger for the study.

Until that on the link below you can find some pictures of my visit in Glarus at Olympia Express and in Schwanden (3 miles from Glarus away) at the HQ of Schätti AG. They assemble the three Olympia models (Cremina, Maximatic and Moka).

Image

https://picasaweb.google.com/114058714406245862917/OlympiaExpressGlarus?authuser=0&feat=directlink

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naked-portafilter
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Postby naked-portafilter » Jun 30, 2015, 3:48 pm

I bought today the 4 channel temp logger, two sensitive (0,75mm) thermocouples for measuring inside the group (in the chamber: below and above the piston). I'm planning to get inside the group through the piston rod. We will drill a 3mm hole inside the rod to have place for the sensors. I'm planning to measure the boiler temperature and the temperature of the group outside.

I can use my old two channel temp datalogger to measure the water temperature at the surface of the coffee cake and maybe to measure the temp of the espresso.

All I need to start the measures is the new stainless steel piston used in the recently assembled Creminas. I have the previous one, made of brass.

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cozy

Postby cozy » Jul 01, 2015, 10:40 am

Great factory shots thanks!

jonr

Postby jonr » Jul 01, 2015, 12:53 pm

Consider measuring temperature just above and just below the coffee. Anything in the middle of the coffee is likely to suffer from variability due to the exact depth.