Mega Crem 2 group - Rebuild...

System

Mega Crem 2 group

Manufacturer: Expobar
Dimensions: 700 mm (W) x 580 mm (D) x 510 mm (H)
Weight: 65 kg | Phase: Single Phase
Maximum installed power: 3050 Watts

Picked it up today...  Some minor cosmetic issues with broken clinch nuts in the plastic covers at the side AND Group Seals and Shower screens so dirty....  These will be REPLACED ASAP.

Not sure what to do with it after that  ;D

Take a leg out of the element to run from 10A socket  maybe.....

No groups, so will be looking for a couple of them and I guess wooden handles can be fitted..

Still NO LEVER  :o :o :o

mycuppa

Pimp up a bit AM. There is a nice flow restrictor mod you can get relatively easily.

blanyon

do tell? And for someone who has been reading about flow restricters for some time, what are they and what do they do? Brett

WotB

They have something to do with temperature stability I believe.  Reduce the wild fluctuations in temperature with increased flow.

mycuppa

on 1306987714:

They have something to do with temperature stability I believe.  Reduce the wild fluctuations in temperature with increased flow.

Not quite WOTB - but close. Thermal stability is a design and control area. The restrictor is fitted in the group head, so it's after the boiler and H/E. A flow restrictor is a small "jet" generally made of teflon (so scale won't stick to it) and it sits above the group head to govern the flow of hot water through the group. If you are looking down on top of the group head, you will notice a big bolt. The flow restrictor sits inside that area, e.g. the bolt must be removed for access - there is also a filter/screen unit in there as well. WARNING !!!!!!!  Please be very careful if you embark upon removal and refit of flow restrictors. They are very small in diameter (like under a mm) and when you attempt to remove the bolt, all sorts of debris MAY fall into the opening and clog your group and/or block the jet completely. Yes, that means it could end in tears. It's a job for clean hands, clean working area and advice is to run the water at low pressure whilst you are removing and reinserting the jet, that way if any foreign debris happens to fall in the area, the water will push it out and avoid being lodged in there causing extra problems. Now, the purpose of the flow restrictor is to slow down the saturation and extraction of the coffee, creating a situation whereby additional (or extra) flavour can be extracted from the shot. Think of it this way, as the water passes through the puck, it can pickup more "stuff". Some balancing needs to be done to grind and dose, but overall I've experienced improved results from the machines I've had the mod applied to. Another experience is that not all "jets" are created equal. As they are mostly made of teflon, the jets can have even a minor difference in diameter (and we are talking here about thousands of an inch, or mm) this can have a dramatic effect on shot time/volume as this is controlled by turns of the flow meter, not amount of water passing through. As an example, 2 group machine with the same flow restrictors fitted, one was delivering 30ml and the other 40ml. A quick resize of the small jet with jewellers drill managed to bring tham back a little closer.

mycuppa

AM - flow restrictors are available from Expobar - they are very cheap considering the profound improvement it can have on flavor. The Expobar folks will probably tell you the "clean"caveat REL install. These sort of machines are a dime a dozen - fix it up, get it sold and move closer to your dream of a lever