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Thread: Adjusting the Pressurestat on the Minore II

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    Adjusting the Pressurestat on the Minore II

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Inspired by another thread regarding Dual Boiler Prosumers, the idea of adjusting the pressurestat to boost the steam power went spinning around my head. Im kinda ok, with how it is at the moment, but wouldnt mind having a fiddle - if its a smart thing to do or not.

    Has anyone done this sort of thing on the Expobars? If it is fiddled with, what else is effected? How much can the boiler/safety valve etc take? I was thinking of maybe of maybe cranking it up to around the 1.2-1.3 bar range. Ive heard of people with international spec machines having it as high as 1.5-1.6bar :o. That sounds ridiculous to me... but who knows?

    I cant remember exactly what it ranges from at the moment, but I think its around the 0.9-1.1bar area. Ill have to get a better look when i get home tonight.

    Thoughts?

    YeeZa

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    Re: Adjusting the Pressurestat on the Minore II

    Quote Originally Posted by YeeZa link=1219283242/0#0 date=1219283242
    Inspired by another thread regarding Dual Boiler Prosumers, the idea of adjusting the pressurestat to boost the steam power went spinning around my head. Im kinda ok, with how it is at the moment, but wouldnt mind having a fiddle - if its a smart thing to do or not.

    Has anyone done this sort of thing on the Expobars? If it is fiddled with, what else is effected? How much can the boiler/safety valve etc take? I was thinking of maybe of maybe cranking it up to around the 1.2-1.3 bar range. Ive heard of people with international spec machines having it as high as 1.5-1.6bar *:o. That sounds ridiculous to me... but who knows?

    I cant remember exactly what it ranges from at the moment, but I think its around the 0.9-1.1bar area. Ill have to get a better look when i get home tonight.

    Thoughts?

    YeeZa
    Hi Yeeza,

    It will affect the offset and therefore the group temp as the steam boiler contains the HX- which carries warm water to the brew boiler.

    Not something Id consider without a scase. In addition, youd put a whole heap more load on your pressurestat...

    Chris

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    Re: Adjusting the Pressurestat on the Minore II

    Hmm yeah that was my fear - it could end up an expensive mod.

    Better pressurestat (if it fits, Sirais are big, Jaeger?, I cant even remember whats in it now), changing the offset isnt a prob, hotter water heading into the brew boiler from the HX.....

    hmm....

    Id like to add a scace to my quiver on day ::)

    thinking, thinking....

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    Re: Adjusting the Pressurestat on the Minore II

    yeeza - 2 qs:
    1. do u work in a cafe / on commercial machines?
    2. do u find that the steam power is a little lacking? i know that you already mentioned that the VBM DS has sig. better steaming power, but when do you most feel that you wish you had more steam? is this just when making one or two coffees, or making back to back drinks?

    thanks mate
    always happy to inspire, always happy to vicariously experiment (with someone elses equipment...)

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    Re: Adjusting the Pressurestat on the Minore II

    Hey Aaron,
    I wouldnt say I work in a cafe, I do a bit of playing around on their machines though ;). Not day to day anyway.

    I guess the amount of steam isnt the problem, its most noticeable when I use bigger jugs, which is rare. I rarely use the 1L at home. I dont usually go over the 600ml jug. I use the 300ml 75% of the time. Maybe Im just used to using the smaller jug, that when I get to a bigger one it seems to take a lot (but not a massive amount)longer (which makes sense, duh). I guess Im just sussing out the option of upping it in the steam dept. just cos I am a guy and always want more power.

    Ive had the machine pumping out 30-40 coffees back to back with one person on shots, one on milk. Probably not meant to do that that often, but it was good to know it could cope. Funny thing is that it seemed to get stronger as it went on.

    Aaron, youve been fluffing around for ages mate, just get one and be done with it hahaha. I guess the best way is to go and play with them all VBM DS DB, Minore, Vivaldi.

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    Re: Adjusting the Pressurestat on the Minore II

    ah danier-son, patience ;)
    its gonna happen in a few months - its a graduation present to myself for 8 long uni years (equiv to 2.5 human years)

    i wanna keep things under 2.5k
    i want rotary
    i want temp stability and tweakability
    i dont want to wait months for special delivery!

    so its the minoreII by two hairs, and in the back of my mind im toying with a used faema/chumbly e98 one group rotary...

    i will pay chris a visit ( i swear chris) and hope to compare some shiny metal side by side. i know theyre all pretty much in the same league but each one is an individual and imperfect (unlike moi)


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    Re: Adjusting the Pressurestat on the Minore II

    Ok so I checked the measurement of the guage of the pressure and it read max 1.2bar.

    Then curiosity got the better of me so I lifted the hood to see what type/model of pressurestat I had, and what other options I potentially have. Anyone know what it is?

    I dont know if its actually adjustable - Im guessing it is. Theres a cog/dial part that can turn. Its the piece with the teeth about half way up on the pic. Anyone wanna shed some light?



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    Re: Adjusting the Pressurestat on the Minore II

    I cant see any real markings that let me know what make it is. I always thought it a MA-TER pstat, but cant see anything.

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    Re: Adjusting the Pressurestat on the Minore II

    I think the Expobar has plenty of steam power as is.

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    Re: Adjusting the Pressurestat on the Minore II

    Anyone got any joy for me re: this pressurestat? My finger is getting itchy with wanting to have a play, but I dont want to blow anything up.

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    Re: Adjusting the Pressurestat on the Minore II

    Quote Originally Posted by YeeZa link=1219283242/0#9 date=1219620202
    Anyone got any joy for me re: this pressurestat? My finger is getting itchy with wanting to have a play, but I dont want to blow anything up.
    Hi YeeZa

    The pressurestat is adjusted using the wheel you have found. I trust the machine is out of the warranty and you are footing the bill for any unplanned consequences of this experiment?

    My previous comments stand. You will change the offset and therefore group temperature which will no longer relate to what you see on the display. In addition, this model pressurestat may not cope with higher pressure. As for the breaker valve on the steam boiler, who knows?

    One small adjustment will have multiple effects and as is not recommended.

    Chris

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    Re: Adjusting the Pressurestat on the Minore II

    YeeZa,

    As Chris says above..... be VERY careful about adjusting anything on one of these machines unless you are 110% sure you know what you are doing!!!

    Tuning coffee machines is a real art/skill set and everything interacts (except on dual boilers)..... and although you might not blow anything up..... you can easily destroy the delicate balance.... lots of steam but cr@p espresso!!

    I run 0.9 - 1.1 Bar and its heaps for a 1.5L jug...... admittedly I have a 17L boiler behind that ::)

    Just remember these machines have been set up by people who know a lot more than we do... and qualifications in thermal dynamics arent something you get out of a Weetbix packet.....

    So be careful..... VERY careful...... if you do choose to proceed (personally with a machine like yours - I wouldnt take the risk).

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    Re: Adjusting the Pressurestat on the Minore II

    Yeah all good advice Chris, and yeah Ive decided to not muck around with it anymore... for now ;)

    The guess and check option probably isnt the smartest as its already a fine tuned machine.

    Just for interest sake, do you know what model the pressurestat is?

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    Re: Adjusting the Pressurestat on the Minore II

    Quote Originally Posted by YeeZa link=1219283242/0#12 date=1219623220
    Yeah all good advice Chris, and yeah Ive decided to not muck around with it anymore... for now ;)

    The guess and check option probably isnt the smartest as its already a fine tuned machine.

    Just for interest sake, do you know what model the pressurestat is?
    Hi YeeZa,

    In my experience so far, it seems to be unique to Expobar. It may be used in other machines, but I am yet to see one in anything else.

    regards

    Chris

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    Re: Adjusting the Pressurestat on the Minore II

    just to add to this, sent my minore I to slades (the importers) for a service / switch replacement.
    they upped the steam preassure to 1.1, and discussed with me first etc...
    so maybe a small tweak is OK?

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    Re: Adjusting the Pressurestat on the Minore II

    Anyone adjusted the steam pressure yet?

    Mine sits at 1.2, then when switched on goes down to .9.
    Would love it to sit at 1/1.1ish while steaming.


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    Re: Adjusting the Pressurestat on the Minore II

    Quote Originally Posted by 1820293C0A2731480 link=1219283242/15#15 date=1246350663
    Anyone adjusted the steam pressure yet?

    Mine sits at 1.2, then when switched on goes down to .9.
    Would love it to sit at 1/1.1ish while steaming.
    Howdy phatboy,

    If you do this, it will have an influence on group temperature as the brew boiler water passes through a HX in the steam boiler. Youd have to scace the machine and adjust the offset again.

    2mcm

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    Re: Adjusting the Pressurestat on the Minore II

    Thanks 2mcm,

    Is the Minore 3 set at a higher steam pressure?
    Can you adjust the steam pressure through the PID on the M3?

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    Re: Adjusting the Pressurestat on the Minore II

    Quote Originally Posted by 7D454C596F42542D0 link=1219283242/17#17 date=1246362209
    Thanks 2mcm,

    Is the Minore 3 set at a higher steam pressure?
    Can you adjust the steam pressure through the PID on the M3?
    Good question phatboy...

    So far, I have not been able to adjust anyting but temp as the MIII is still shipping with the manual for the MII controller. I guess there has to be a way though.. ::)

    The M3 has more steam grunt but still runs at around 1.1bar. I suspect the improved performance is due to more rapid recovery as it now runs 2 x 2kw elements- switched independently.

    Chris

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    Re: Adjusting the Pressurestat on the Minore II

    strange...today it steamed at a steady 1.1....
    do the gauges lose calibration easily over time, are they cheapies?

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    Re: Adjusting the Pressurestat on the Minore II

    Quote Originally Posted by 0931382D1B3620590 link=1219283242/19#19 date=1246449389
    strange...today it steamed at a steady 1.1....
    do the gauges lose calibration easily over time, are they cheapies?
    Could be condensation collecting in the capillary tube from the connection point to the gauge. Its quite amazing just how much this can affect the accuracy reported by the gauge. If this is the cause of the problem, disconnect the capillary at the back of the gauge before turning the machine on next time, and allow the pressure build-up to push any condensate from the tube until you observe nothing but Steam then reconnect to the gauge while the pressure continues to build. Might need gloves... :P

    Mal.

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    Re: Adjusting the Pressurestat on the Minore II

    Can anyone recommend a sponsor in Brisbane who knows there way around an Expobar (calibrate pressure etc). I know someone who really needs to get his machine looked at. I dont think it has ever made a good coffee since day one.



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