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VBM Vashetta/Levetta/Piccolo Cooling Flush

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  • TC
    replied
    Re: VBM Vashetta/Levetta/Piccolo Cooling Flush

    For those in Sydney, NB this one- http://coffeesnobs.com.au/YaBB.pl?num=1163933911/8#8

    Chris

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  • PhilMac
    replied
    Re: VBM Vashetta/Levetta/Piccolo Cooling Flush

    Originally posted by flynnaus link=1223335640/20#37 date=1224388951
    Im starting to agree more that Erics ThermoAdapter would be a good way to go if it will help provide a consistent result.
    I think  a poll is in order to see if other CS are interested in getting one. We might get a discount for a bulk order or at least save on postage?
    Id be in on that.

    Originally posted by Banjo link=1223335640/40#44 date=1224478335
    im also looking to head down to see Renzo and Ofra on my next day off to get the Scace 2 hooked up and check the pressure as well

    Darren
    Feel sorry for us in the Brisbane wastelands.....

    Cheers

    Leave a comment:


  • Banjo
    replied
    Re: VBM Vashetta/Levetta/Piccolo Cooling Flush

    Well Steve it is Nescafe Blend 43 8-)

    its not like im sitting here drinking International Roast or Bushells

    Darren

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  • flynnaus
    replied
    Re: VBM Vashetta/Levetta/Piccolo Cooling Flush

    Originally posted by Banjo link=1223335640/40#44 date=1224478335
    Im sitting here having a cup of instant coffee  
    Blasphemy! Times may be grim Darren but careful who you admit that to on here :P

    Leave a comment:


  • Banjo
    replied
    Re: VBM Vashetta/Levetta/Piccolo Cooling Flush

    hi Jim

    well i initially adjusted it a tad after thinking it was a little cool and especially after reading about Philmac and his experiences, so the adjustment i made i thought was for the better but then i asked the question on here about the water spitting and spluttering during a flush after sitting idle and the response i got was this wasnt normal and maybe my temp was too high so i got a little nervous about this not knowing exactly where it was so i bumped it back.

    Where it is now i wouldnt know but you have calculated around the 88 mark. Im sitting here having a cup of instant coffee and have the machine warming up so i plan to have another play and might look to putting the thermocouple on top of a puck and measure from there.

    oh and how does the coffee taste lately ? very ordinary

    im also looking to head down to see Renzo and Ofra on my next day off to get the Scace 2 hooked up and check the pressure as well

    Darren

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  • jggall01
    replied
    Re: VBM Vashetta/Levetta/Piccolo Cooling Flush

    Originally posted by Banjo link=1223335640/40#42 date=1224394520
    ...the boiler would cut in and then the temp would drop by a further .3 - .5 to cut out and then it would rise and level out and then start dropping away to repeat the cycle
    I think I understand whats going on (I had been struggling to explain why the temp would drop after the heater cut in, and then rise so much after it cut out).

    The answer is that the group temperature cycle is out of phase with the boiler temperature cycle.  The group lags behind.  I have also observed this on Silvias, and should have recognized it initially.

    I wouldnt have predicted that the group temperature would fluctuate by 6 degrees, but thats why you do the test, right?  If your readings show this happening consistently and on a cyclic basis, then I think its a sign of good measurements.

    Using your results, I calculate the average group temperature to be ~88C.  To me, this would seem to be at least 3C low.  What happens to the taste of your coffee if you turn the thermostat up a tad?

    Jim

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  • Banjo
    replied
    Re: VBM Vashetta/Levetta/Piccolo Cooling Flush

    PIDKits wrote:
    I am really quite surprised that there is so much variation in the group temperature.  I am also having a bit of trouble understanding your numbers  undecided

    What is it that causes the temperature to rise to 91?  Is this the peak of each heating cycle?  Was the machine fully warmed up when you made your measurements?

    I am searching for some explanation of how such a large chunk of brass (the E-61 group) manages to vary by 6 degrees during each cycle
    hi Jim, yep fully warmed and even when i bumped the temp up a tad it retained that 5-6 degree swing, i wrote down the numbers 3 times and all pretty consistent.
    the boiler would cut in and then the temp would drop by a further .3 - .5 to cut out and then it would rise and level out and then start dropping away to repeat the cycle

    i wrapped insulation tape around the probe so it was a tight fit into the thread and had approx 15mm inserted from the start of the thread

    oh and Intelli i will get another tomorrow just in case  

    Darren

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  • jggall01
    replied
    Re: VBM Vashetta/Levetta/Piccolo Cooling Flush

    Originally posted by Randy G. link=1223335640/20#31 date=1224377667
    Let me begin by saying that Jims method of checkng the idle temperature might work for some, and it can give you some sort of starting point for adjusting, but depending on the machine, a 91 to 92C idle temperature very well may create an undesirable brew temperature. Erics testing has shown that even 1mm difference in the placement of a thermocouple will change the tempeature readings.

    When an E-61 grouphead is at idle it can get quite hot. When I flush mine in preparation for a pull the thermometers display immediately jumps to about 98 C. and sometimes a bit higher. If you set the pressurestat to give the correct temperature at that point, the boiler temperature will be very low. Now, that sounds very hot (and it is), but I flush until it reads about 95 C. (203.5 F). At that temperature, the majority of the shot (at the end portion) is at about 91 C. (195 F.).  This is with the slow reacting digital thermometer that Eric sells with the kit. A thermocouple with a small mass would react faster and possibly give different readings.
    A few comments might be helpful here.  The E-61 group on a single boiler machine runs quite a bit cooler than a similar E-61 group on an HX.  The SB machine still has a thermosyphon loop, but the temperature in the loop is a lot lower.  The other significant difference is that flushing warms up the group on a SB, while it cools down the group on an HX.  I also think (but dont know for sure) that there is a lot less grouphead temperature variation from machine to machine when considering SB E-61s.

    Secondly, I fully agree that placement of the tip of the probe makes a big difference for dynamic measurements, i.e., while water is flowing through the group.  But for measurements of the idling grouphead temperature, placement of the probe is not nearly as important (because all of the metal in the vicinity is the same temperature).

    Ill be very surprised if we dont start seeing some kind of thermometers being built into groups.  I dont think it would cost much at all to install a dial gauge.  There was/is a single boiler machine in the Silvia-class that has a dial guage group thermometer.  Unfortunately, I can no longer remember the brand or model  :-X

    Jim

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  • jggall01
    replied
    Re: VBM Vashetta/Levetta/Piccolo Cooling Flush

    Originally posted by Banjo link=1223335640/20#28 date=1224374586
    Jim i did what you suggested with the idle temp check after Intellidepth was so kind to lend me her multimeter/thermocouple ( along with bottomless portafilter, milk temp probe and 2 bags of coffee  , i was almost waiting for her to bring the Super Lever out for me as well   ) and i found the boiler cutting in around the 85.3 and cut out at 84.8 before rising to a max of 91 and then dropping away to repeat the cycle.
    I am really quite surprised that there is so much variation in the group temperature.  I am also having a bit of trouble understanding your numbers  :-/

    What is it that causes the temperature to rise to 91?  Is this the peak of each heating cycle?  Was the machine fully warmed up when you made your measurements?

    I am searching for some explanation of how such a large chunk of brass (the E-61 group) manages to vary by 6 degrees during each cycle.

    Originally posted by Banjo link=1223335640/20#28 date=1224374586
    I personally think that the money we are spending on these machines that the manufacturers should be putting some kind of reference device on them to give us half a chance of getting it right  
    Thats a horrible thing to suggest.  Think of all the blokes who provide aftermarket temperature control systems who would be on the street  8-)

    Jim

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  • Intellidepth
    replied
    Re: VBM Vashetta/Levetta/Piccolo Cooling Flush

    Originally posted by Banjo link=1223335640/20#30 date=1224377145
    ...that way im not risking any damage to Intellidepths thermocouple.
    ;D What Banjo hasnt mentioned are the brown stains at the end of my thermocouple as a result of roasting and it being stuck in the real brew flow here and there ;D Not pretty. Banjo you have my full permission to jam it in the PF on top of a puck if youre game - I was going to attempt that when I got it back anyway.

    Leave a comment:


  • Randy_G.
    replied
    Re: VBM Vashetta/Levetta/Piccolo Cooling Flush

    From my dealings with him, I would say that Eric S. really is a great fellow. iircc, he makes no profit from the sale of the adapters- he only requires a separate check as a donation to CoffeeKids.. I suggest you contact him, or possibly go through a site sponsor, and see what you can work out.

    Leave a comment:


  • flynnaus
    replied
    Re: VBM Vashetta/Levetta/Piccolo Cooling Flush

    Originally posted by Randy G. link=1223335640/20#31 date=1224377667
    The only thing that matters is what is in the cup. if you can make delicious espresso, who cares if the puck pours out like roofing tar? But it does sound like you still have some work to do. Do what you can to get another barista- home or pro, over to your place and see what they can do. It can be a real revelation to have an experienced person mess with your equipment.
    Thanks Randy

    I will keep that advice in mind. This thread is in danger of leaking into the stiff lever thread - messing with equipment and naked portafilters indeed!

    But I need to get the dose/distribute/tamp part right so that it is constant. As you say, consistency but not just im the tempareature aspect.

    I will dial the grinder finer as Im getting there but the naked pf will help me diagnose that aspect. I think I may be there but using the WDT showed my my distribution has been incorrect.

    Im starting to agree more that Erics ThermoAdapter would be a good way to go if it will help provide a consistent result.
    I think a poll is in order to see if other CS are interested in getting one. We might get a discount for a bulk order or at least save on postage?

    Leave a comment:


  • Dennis
    replied
    Re: VBM Vashetta/Levetta/Piccolo Cooling Flush

    I see where youre coming from Darren and dont disagree entirely. Though as an example, I see many 4WDs on the road that are built to do what 95% of people never use them for. So while we snobs (the other 5%) may want to get the best out of the equipment by using fresh beans, investing in training, etc. it stands to reason that we may also want to tweak the equipment to our own specifications. I think if we go back to the example of the 4WD, people who would like to use these vehicles to their full potential are also likely to make further modifications.

    Perhaps what manufacturers do is present us with a piece of equipment and say, this is capable of producing good coffee. It wouldnt hurt to offer some guidelines as to how to achieve this. Though as there are so many variables with coffee, that often come down to our personal tastes, I dont think making coffee to suit these tastes can ever be formulaic, unless of course we have a perfect superauto...and wheres the fun in that!

    Leave a comment:


  • Banjo
    replied
    Re: VBM Vashetta/Levetta/Piccolo Cooling Flush

    hi Dennis, yes the good old cost factor.

    So i can only assume the manufacturers couldnt care less if the consumers are actually getting their moneys worth out of the machines and using them to their maximum.

    this whole episode has left me scratching my head, there are no hints/tips as to when the best time to extract is, and as we know that magic area does indeed exist so why not give the consumer some kind of chance of getting the most from their purchase.

    Darren

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  • Randy_G.
    replied
    Re: VBM Vashetta/Levetta/Piccolo Cooling Flush

    Originally posted by Banjo link=1223335640/20#32 date=1224379048
    Randy G. wrote:
    The point is (and you knew I would get to it eventually, didnt you?) that with the thermometer you can begin every pull at the same temperature, and that is... Class? Anyone? No hands? Tye answer is CONSISTENCY!
    Exactly, so why is it that these machines are sold without a thermometer? my way of thinking in all this is they are manufacturing a machine that at the end of the day is possible of pulling consistent shots but they arent exactly helping us get there quickly are they?
    Are there any E-61 machines sold with a thermometer in the brewhead? I dont remember seeing any. You also make the point that the Italians have been making great espresso for a long time with so little regard to tamping that they nearly ignore any technical details about that step of the procedure completely. Yet, if you choose, you can spend some $100 on a tamper that clicks at some precise, predetermined force. So there are things we "need" that dont exists, and things we dont need that do...

    The E-61 brewhead can be considered a commercial design, and in that environment where it is making shots on a regular basis the design performs as originally designed; with remarkable consistency, pull after pull. In the home, when the machine can sit idling, unused for extended periods of time, overheating of the brewhead can be the result.

    Now, considering that with the addition of an easy-to-install thermometer, the VBM with its "original design" brewhead can out perform a PID-equipped Silvia by a long shot, we can lament that the thermometer is not originally supplied, or we can bite the bullet, install one, and enjoy fabulous espresso day after day.

    Leave a comment:

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