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Thread: Decent Espresso Machines (DE1) - Any thoughts?

  1. #1701
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    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Quote Originally Posted by gc View Post
    I pour the water into a little jug and then add slowly to the coffee to retain the crema. I've found the water pour rate from the DE destroys the crema if poured onto the espresso shot.
    Now why didn’t I think of that... not just applicable to the DE of course!
    Btw nice to see another CSer with early morning wife coffee duties! Happy wife happy life...
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  2. #1702
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    Just add the extra water to the cup first and the pour the shot on top, you'll keep the crema that way (and if you want it to taste better scoop the crema off before drinking).
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  3. #1703
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    Quote Originally Posted by level3ninja View Post
    Just add the extra water to the cup first and the pour the shot on top, you'll keep the crema that way (and if you want it to taste better scoop the crema off before drinking).
    I used to do that, but found it difficult to judge just the right amount of water first. Of course, now with the DE, I can just dial in a quantity of water [even though the displayed quantity is completely wrong - it's always consistently wrong], I guess I just got into the habit of shot first > water.

  4. #1704
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    Quote Originally Posted by gc View Post
    I used to do that, but found it difficult to judge just the right amount of water first. Of course, now with the DE, I can just dial in a quantity of water [even though the displayed quantity is completely wrong - it's always consistently wrong], I guess I just got into the habit of shot first > water.
    I would think there is probably a way to calibrate it no? Have you sent a message to the boss man, he might be on set though so may be slow to respond, but he is usually pretty snappy.

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    evaluating the Rok grinder

    rok.jpg

    After watching a review of the ROK espresso machine by James Hoffmann I got in touch with Patrick, the founder.

    I would love to see the Rok work with the Bluetooth pressure transducer from Kávékalmár so that people can move espresso profiles back and forth between a Decent Espresso machine and a Rok (using the Smart Espresso Profiler app). Perhaps you want to use the Decent every day at home, and then take the Rok on holiday with you, and copy your favorite shot by hand?

    Or maybe you managed an outstanding shot on the Rok and would like the Decent to try to copy it? I’m happy to report that I’ve introduced Patrick and Gabor to each other, and they’re working on it now.

    James indicated he was impressed by the Rok’s hand-grinder, and I’m interested to test it out with the Decent. Its price and quiet operation, if it makes acceptable shots, would make it something I’d very much recommend. I like how it looks next to the Decent too.

    I’d also like to call out the Rok’s exceptionally clearly written, wonderfully short, generous warranty statement.

    -john
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  6. #1706
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    Quote Originally Posted by gc View Post
    I used to do that, but found it difficult to judge just the right amount of water first. Of course, now with the DE, I can just dial in a quantity of water [even though the displayed quantity is completely wrong - it's always consistently wrong], I guess I just got into the habit of shot first > water.
    I've been visually checking the weight in the cup after I asked for 60ml of hot water. I find that a 10% error is typical, but I don't typically get more than 20% error.

    Getting very small amounts of water out of the hot water spout at a precise quantity is quite difficult, because we don't know ahead of time how much air is in the water tube. Larger quantities of water should be more accurate, within 10%.

    I don't know if you're running the current or older firmware?

    The current firmware should be more accurate at dosing hot water, since we've rewritten the flow metering algorithms.

    At any rate, if you're looking for precision dosing of hot water my recommendation is to buy our Bluetooth scale, and set the water dose to what gives you the in cup weight you were looking for.

    – John

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    "God shots" extended

    godshots.gif

    God shots are now named and saved permanently to disk. This also means they can be shared between people (for now: via file copying, eventually through a cloud service).

    This new feature allows you to store a number of approaches to different espressos ("God shots") that have worked for you in the past.

    I am working with the decent community and Scott Rao to collect a library of well-executed shots that used the built-in presets.

    My thinking is that if we provide a preset, as well as a trace of a well-executed shot that will greatly help people correctly pull that espresso profile. A common question often arises as to what the grind should be for a given profile. With a God shot to follow, you should adjust the grind until you are able to match the God shot.

    In a future tablet release, God shots for the most popular profiles will be included by default, to help you dial in your shots even further.

    Another way to use this feature is to save good expressions of an espresso extraction, and then be able to visually compare them.

    -john
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  8. #1708
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    Quote Originally Posted by decentespresso View Post
    I've been visually checking the weight in the cup after I asked for 60ml of hot water. I find that a 10% error is typical, but I don't typically get more than 20% error.

    Getting very small amounts of water out of the hot water spout at a precise quantity is quite difficult, because we don't know ahead of time how much air is in the water tube. Larger quantities of water should be more accurate, within 10%.

    I don't know if you're running the current or older firmware?

    The current firmware should be more accurate at dosing hot water, since we've rewritten the flow metering algorithms.

    At any rate, if you're looking for precision dosing of hot water my recommendation is to buy our Bluetooth scale, and set the water dose to what gives you the in cup weight you were looking for.

    – John
    I'm running the latest firmware and do use the Skale as you suggest, but still find variance in the water out. eg I set to 70ml but get somewhere between 85-100mls out [by weight] My [very faulty] recall is that it used to be more accurate for pouring water on the FW before June, but it is now much more accurate in other areas that matter more so I'm not really complaining.

    I tried making coffee with my old San Marino Compak today as I hadn't used it since receiving my DE1+ in May. Its a very forgiving machine compared to the DE and made OK coffee straight off, but I was standing there wondering "what's it doing now?". No temp control short of a crude flush to lower water temp at the groupe, no pressure control, or flow control, just grind dose and time. Getting just the right qualities I like from my favourite roasts is a challenge on the DE but very rewarding in the end, whereas it never occured to me to "tweak" the old HX - or if that was even possible. The one thing I did miss though was just a gentle tap on a dry puck into the knock box. So much better than the sloppy pucks on the DE. Sigh........

  9. #1709
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    Quote Originally Posted by gc View Post
    I'm running the latest firmware and do use the Skale as you suggest, but still find variance in the water out. eg I set to 70ml but get somewhere between 85-100mls out [by weight] My [very faulty] recall is that it used to be more accurate for pouring water on the FW before June, but it is now much more accurate in other areas that matter more so I'm not really complaining.
    If I could bother you to whip your camera phone out a few times when you use the hot water function, and take a photograph of the final weight as well as the tablet settings, that would really help. Then please post those photos to the owner's diaspora group. I haven't seen more than 10% error myself or from others on the forum, so what your reporting is beyond what I'm okay with and I'd like to resolve it.

    PS: sorry about the wet pucks, it's the price to pay it seems for higher extraction levels. People have reported being able to make dry pucks on the decent espresso machine with different profiles that extract less.

    – John

  10. #1710
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    Quote Originally Posted by decentespresso View Post
    If I could bother you to whip your camera phone out a few times when you use the hot water function, and take a photograph of the final weight as well as the tablet settings, that would really help. Then please post those photos to the owner's diaspora group. I haven't seen more than 10% error myself or from others on the forum, so what your reporting is beyond what I'm okay with and I'd like to resolve it.
    – John
    Many thanks John. Will do. Hope screenshots are OK and will text in final weight on Skale.

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    Quote Originally Posted by decentespresso View Post
    rok.jpg

    After watching a review of the ROK espresso machine by James Hoffmann I got in touch with Patrick, the founder.

    I would love to see the Rok work with the Bluetooth pressure transducer from Kávékalmár so that people can move espresso profiles back and forth between a Decent Espresso machine and a Rok (using the Smart Espresso Profiler app). Perhaps you want to use the Decent every day at home, and then take the Rok on holiday with you, and copy your favorite shot by hand?

    Or maybe you managed an outstanding shot on the Rok and would like the Decent to try to copy it? I’m happy to report that I’ve introduced Patrick and Gabor to each other, and they’re working on it now.

    James indicated he was impressed by the Rok’s hand-grinder, and I’m interested to test it out with the Decent. Its price and quiet operation, if it makes acceptable shots, would make it something I’d very much recommend. I like how it looks next to the Decent too.

    I’d also like to call out the Rok’s exceptionally clearly written, wonderfully short, generous warranty statement.

    -john


    On the good looking grinder topic ... just received my new 63mm burr grinder before Christmas. Should look great once my DE1PLUS arrives ...

    There is a quite detailed review on it too: https://www.nichecoffee.co.uk/wp-con...ero-review.pdf





    -- lars


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    What a tired gasket does to espresso

    You can see that the shot ended about 7 seconds earlier than desired. The drink reached the requested final "in cup weight" sooner, due to the water dripping around the gasket, bypassing the portafilter. Yummy.


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    Quote Originally Posted by decentespresso View Post
    The drink reached the requested final "in cup weight" sooner, due to the water dripping around the gasket, bypassing the portafilter. Yummy.
    It's just another route to an Americano.

    Literally.
    Last edited by Lyrebird; 3 Weeks Ago at 08:36 PM.

  14. #1714
    gc
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    A dumb question:

    I just purchased Cafelat blue 8.5mm silicon gaskets for my DE, but am not sure whether when fitted, the smooth surface should should contact the portafilter rim, or whether the face with the bevelled edges and the Cafelat label should be in contact with the portafilter basket rim?

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    Bevelled edge up, smooth surface down - Towards PF Filter Basket...

    Mal.

  16. #1716
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    Quote Originally Posted by Dimal View Post
    Bevelled edge up, smooth surface down - Towards PF Filter Basket...

    Mal.
    Thanks Mal. We all have to learn the first time I guess.
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    Decent Suitcase v2

    suitcase5.jpg

    In March, we plan to have shipped 200 v1.1 espresso machines, and with the 300 v1.0 machines already shipped, that will have used up all 500 suitcases that we originally had made 18 months ago.

    I'm taking the opportunity to make some improvements to the decent espresso suitcase which comes with our espresso machines.

    The biggest change will be moving from compressible foam to Styrofoam in the outer walls.

    The goal is to avoid damage to the legs which has been a problem throughout the version 1.0 manufacturing run. The most common cause of this problem is UPS tilting the machine 90° and then stacking a lot of weight on top. The foam we have been using compresses fully in this scenario and shock is transmitted to the legs. Eventually, metal fatigue occurs and the legs bend.

    We think that with Styrofoam, which will only slightly compress under load and continue to absorb shock, that we can avoid this sort of damage.

    Since we're making this change before the suitcases are made, we can get the Styrofoam cut to measure and inserted underneath the fabric. That way a 4cm (1.5") thick piece of Styrofoam will be hidden between the fabric and the suitcase walls. In the photos below, we have sliced open the fabric in order to test out various scenarios.

    For aesthetics, we are also changing the fabric to black.

    The middle layers will continue to be molded EVA foam, spandex covered, with hand-sewn trim on the edges. This has worked well to hold things in place while still being quite light and odor free. The spandex is easy to clean and does not absorb coffee grounds easily.

    If we get the timing right, the new suitcases should arrive the first week of March, just as we need them. They take so much space that we kind of need them to arrive at the last moment or else we won't have enough storage space here.

    -john

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    v1.1 Shipping Update

    ship_date.jpg

    We have now built 20 V 1.1 espresso machines and are working on the next 20. I expect to send all 40 out next week. That will be 29% of our order backlog taken care of.

    We’ve been scratching our heads for about a week because all our 220 V machines have all been acting strangely, but our 110 V machines have been fine. We worried that we had overlooked something crucial (and expensive to fix. Perhaps the circuit boards were not up to the higher voltage because someone had swapped a component? I didn't want to ship any machines until this problem was solved, even if the problem didn't appear on the 110V machines.

    In order to trace down this problem, we spent the past days greatly enhanced the debug logging that comes out of the espresso machine’s built-in computer. This is now more like an interactive debugging tool for figuring problems out, as you can tap certain keys to get different info. At the moment this info is only available with a special cable, but in the next few months, this functionality will also be available over Bluetooth in the tablet software.

    We finally figured out the problem today.

    The logs clearly showed that something was wrong with the hot water temperature sensor. It turns out that two temperature sensors were swapped position (hot water output and mixed water temperature). One person here had done all the 110V machines’ sensors while another person had done the 220V machines. That's why the error was so regular. It turns out the voltage was a false clue which really derailed us.

    In my final checking, though, I noticed that the first 20 machines did not have the much more expensive IMS filter screens installed. Instead. the "standard" filter screen that we use for our DE1+ v1.1 machines were used. I've now hidden those less good filter screens, and the 20 finished DE1PRO machines will get upgraded this week before we ship them out.

    We will all be pulling lots of espressos on Wednesday and Thursday to test these 40 machines out, and then hopefully shipping on Friday or Monday.

    -john

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    More hardware mods to the Decent Espresso machine.



    Here Decent customer Damian designs a replacement scale battery tray, so as to lock the scale into exactly the right position. He then replaces the drip tray cover so that it connects directly to the scale, for perfect, easy espresso shot weighing.
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    IMG_9580.jpg

    Here's what the first v1.1 Decent Espresso Machines look like from above. I feel like we're getting tidier.

    This weekend, we're putting the final touches on the firmware for automatic refilling, then we're ready to start shipping this new model.

    40 machines for USA/Canada are shipping next week.

    The week after, we'll be busy making 40 machines at 220V for the rest of the world.

    -john
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    The Same Pump around the world



    We are finalizing the firmware for the 220V/240V v1.1 espresso machines, and one thing we still need to do is calibrate our flow calculations for different power around the world.

    What makes this difficult is that the electromagnets in the pumps move a different amount of water at different pressures based on how much electricity (voltage & frequency) is being fed to them.

    We've previously centered our calculations around a 230V average, but now we're trying to do better.

    The animated graphic is the same pressure test program at 220V, 230V, and 240V. You can see the theoretical flow rate that the machine thinks is coming out, and compare that to the brown line which is the real amount of water coming out. At 230V our calculations are pretty good, but they get worse (especially at higher pressures) at 220V and 240V.

    Over the next few days, we're hoping to be able to automatically detect voltage for each machine, regardless of where it is in the world, by comparing the power consumption of our group head heater at startup against what we know it should be at 240V. That should allow us to get calibrate against the measured performance of the pumps at different voltages.

    Hopefully, we'll reach the precision we currently have at 230V, but at 220V and 240V as well.

    Note: this issue doesn't occur with our American/Canadian machines, because 120V is a standard that doesn't vary much, except <sigh> in Japan, which runs at 100V. That's why we were able to start shipping the American/Canadian machines this week, before having resolved this flow calculation issue.

    -john
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    As a stopgap, is there any way to calibrate the pump by setting the voltage manually?

    Autosensing voltage would be a much better long term idea - my mains voltage here varies with three peaks a day from around 230 to 245 over a 24 hour cycle. Apart from coffee, cooking is such a widely moving target I am using a Variac to set the output voltage manually. I would be surprised if even 110V (US) doesn't have the same issues as when I was in Colorado the mains voltage also cycled according to the hourly loads.

    FWIW, my own proper long term fix is to run my own battery and 3 phase inverter system to supplement my current solar panels and feed all cooking gear from that sub system.

    Anyway, if it is not sorted when my Pro turns up I will just add the "220V pro" to the Variac output and set it at 230V.

    TampIt

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    Quote Originally Posted by decentespresso View Post
    Over the next few days, we're hoping to be able to automatically detect voltage for each machine, regardless of where it is in the world, by comparing the power consumption of our group head heater at startup against what we know it should be at 240V. That should allow us to get calibrate against the measured performance of the pumps at different voltages.
    I don't know how tight the tolerances on your elements are, but in my experience in an industrial setting the current they draw can vary by +/-10%. It also changes over time (usually lowers maybe 10-20% over the useable life). Looking at that graph it seems you have around a +/-10% difference between 230 and 220/240.

    If you could get the machine to measure the resistance across the element and then the power draw at each start up you'd have a self calibrating "voltmeter" built in.

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    Quote Originally Posted by level3ninja View Post
    If you could get the machine to measure the resistance across the element and then the power draw at each start up you'd have a self calibrating "voltmeter" built in.
    <grin> That is EXACTLY the approach we are taking. :-)

    The v1.1 Espresso machine models are able to measure current draw, so this is now a possibility.

    Quote Originally Posted by TampIt View Post
    As a stopgap, is there any way to calibrate the pump by setting the voltage manually?
    Yes, of course, that's a fallback. However if it's just another weeks work to get voltage autosensing, then that's my preference. That's we're trying to make work.

    -john
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    Dialing in your grind

    Today I posted a video about dialing your grind in. I find this is something a lot of people new to home espresso making struggle with.

    I tried to keep this simple width:
    1) what it looks like when you have too fine a grind
    2) what it looks like when you have too coarse a grind
    3) how to make small adjustments in flow by varying your dose instead of changing the grind
    4) how to read the decent espresso charts to try to understand how you should change your grind or dose

    Would love feedback on how you think I could help people dial their grinding easier or faster.

    -john

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    Quote Originally Posted by decentespresso View Post
    <grin> That is EXACTLY the approach we are taking. :-)

    The v1.1 Espresso machine models are able to measure current draw, so this is now a possibility.


    Yes, of course, that's a fallback. However if it's just another weeks work to get voltage autosensing, then that's my preference. That's we're trying to make work.

    -john

    G'day John

    Thanks for the fallback on voltage.

    I will happily wait another week if needed. If it can be done via a software update, all the better...

    TampIt
    Do it once, do it right.

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    Quote Originally Posted by decentespresso View Post
    <grin> That is EXACTLY the approach we are taking. :-)

    The v1.1 Espresso machine models are able to measure current draw, so this is now a possibility.


    Yes, of course, that's a fallback. However if it's just another weeks work to get voltage autosensing, then that's my preference. That's we're trying to make work.

    -john
    Hi John,

    You mentioned this data was generated using a known diameter single hole basket. Do you provide these to customers with the machine?

    If so, it might offer another way to do a manual calibration of the machine, since the relationship between pressure and flow through that orifice will be the same regardless of the pump behaviour (and this could be measured in factory)?

    Plotting the data with flowrate on the x axis and pressure on the y axis would show the difference voltage makes much clearer.
    I did this with the data scraped from the 230V chart you posted, the result was quite interesting!

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    Quote Originally Posted by TampIt View Post
    G'day John Thanks for the fallback on voltage. I will happily wait another week if needed. If it can be done via a software update, all the better... TampIt
    Do it once, do it right.
    Actually, I decided that there's no reason to hold up sending 240V machines for this improvement, since we're frequently coming out with firmware updates that improve things. So: five machines at 220V are going out today.

    The next 220 firmware update will be in a week or two and is simply a tap on the tablet to update the software, and then another tap to update the firmware. Easy squeezy cheesy peasy.

    If you are running 220V or 240V., all this means is that your flow estimates will be off by as much as 10% when you are at eight bars or higher pressure,

    However, Tampit if you are in Australia my understanding is that 230V is standard
    https://www.tripadvisor.com/Travel-g...ppliances.html

    In which case our current firmware works perfectly, as that's what we calibrated our flow mathematics for.

    -john

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    Quote Originally Posted by MrJack View Post
    Hi John, You mentioned this data was generated using a known diameter single hole basket. Do you provide these to customers with the machine?
    Yes, that is 100% the idea. I posted about the "puck simulator" accessory here on this forum some time ago:
    https://coffeesnobs.com.au/brewing-e...tml#post631924

    Armed with a Bluetooth scale, a 0.2mm basket (will be available for sale soon ~AUD$30) and the espresso calibration program (which is simply an advanced shot), you'd be able to re-create what we have done.

    Quote Originally Posted by MrJack View Post
    Plotting the data with flowrate on the x axis and pressure on the y axis would show the difference voltage makes much clearer.
    I did this with the data scraped from the 230V chart you posted, the result was quite interesting!
    That's a good insight.

    However, I didn't mean to make you scrape the graphics for the data. Just ask: I'm happy to share the data itself on anything I post.

    Here are three CSV documents showing the three calibration tests at different voltages:
    http://magnatune.com/p/presstests_csv.zip

    Note that these CSV export documents are now created automatically when you save a "god shot", as part of a recent tablet software upgrade I put out.

    -john

    screen 2019-01-15 at 1.50.36 PM.png

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    The first manufacturing prototype of the decent scale arrived on Friday.

    I am mostly quite happy though of course, I have about 20 defects and mistakes I cataloged for our manufacturing partner. Not least of which is the red numeric LED (!!!!???!!!).

    Most importantly, the really hard things they nailed ( The plastic is high quality, doesn't smell, and the mold errors are tiny and repairable), and their attitude to my change list was very positive, so in a few weeks, I should have the second iteration. And I should also get Bluetooth functionality so I can program my tablet to talk to it.



    You can also see the shiny new electroplated drip tray covers, which all of you will be soon receiving.

    -john

    IMG_9652.jpg
    Last edited by decentespresso; 6 Days Ago at 07:15 PM.
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  31. #1731
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    Quote Originally Posted by decentespresso View Post
    However, Tampit if you are in Australia my understanding is that 230V is standard
    https://www.tripadvisor.com/Travel-g...ppliances.html

    In which case our current firmware works perfectly, as that's what we calibrated our flow mathematics for.

    -john
    230 is the "standard" as of a few years ago. They changed the "standard" to 230 from 240 but they also changed the allowable variance to the nominal voltage at the same time. 230 V as the nominal voltage with a +10% to –6% variation at the point of supply. (253 V to 216.2 V). 253 was the maximum back when it was nominal 240, but the minimum at nominal 240 was something like 228(?).

    So what changed at the outlets in our walls when they changed the nominal voltage? Sweet FA, literally nothing. It still depends on how far you are from the nearest transformer. I've had friends who kept blowing appliances after a few months, CFL lightbulbs you could count in weeks. I measured the voltage at the outlet and it was 248V. Outside the "preferred range" of +6% to –2%. (243.8 V to 225.4 V) but well within the allowable limits. The lowest I've every measured in a house is 236V, which was such a surprise I measured a few other outlets and the voltage coming in on the mains to make sure there wasn't a high resistance fault somewhere in the switchboard. I've seen 238 a few times, 239 a handful of times, but 240+ is by far the norm (in Sydney at least).

    TampIt is near Perth, I replaced some lights for a friend a few KMs from him last year and I think it measured low 240s. His house could be different though depending on the distance from the Tx.
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  32. #1732
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    Quote Originally Posted by level3ninja View Post
    So what changed at the outlets in our walls when they changed the nominal voltage? Sweet FA, literally nothing. It still depends on how far you are from the nearest transformer. I've had friends who kept blowing appliances after a few months, CFL lightbulbs you could count in weeks. I measured the voltage at the outlet and it was 248V. Outside the "preferred range" of +6% to –2%. (243.8 V to 225.4 V) but well within the allowable limits. The lowest I've every measured in a house is 236V, which was such a surprise I measured a few other outlets and the voltage coming in on the mains to make sure there wasn't a high resistance fault somewhere in the switchboard. I've seen 238 a few times, 239 a handful of times, but 240+ is by far the norm (in Sydney at least).
    Very helpful info. So, obviously, every machine we ship has to self-adjust to whatever it's given. No "I live in Australia" setting would tell us much.

    -john

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    I'll have to see if I can find an old copy of AS60038, and also look through the old copies of AS3000 & AS3008 at work. It was the drop in voltage that caused headaches for us (and fatter wallets for the cable manufacturers) by requiring us to calculate voltage drop on 230 instead of 240, pushing a lot of formerly normal circuits over the threshold to the next size up cable. From memory the 10% had been dropped prior to 230 coming in and bumping it back up again.
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  34. #1734
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    We've got a very responsive energy service group out our way, luckily.
    I charted the voltage variation in our neighbourhood over a two month period to prove a point.
    Voltage used to peak at 262V AC and bottom out at 238V AC for a nominal 230V AC supply. Requested that they check out the local kiosks, sub's etc... and within a week, the service crew turned up at our house to verify my instruments against their own. They were satisfied with the accuracy and method used then indicated that they would be happy to do some measurements of their own around the local district.

    The upshot was, that they adjusted the tap settings on a main distribution txfr and then did the same to a number of kiosks/sub's as well. Our local voltage now sits reliably between 228 - 242V AC so not too bad an outcome in the end. Anyone whose local supply voltage is significantly out of spec' might benefit from completing a similar exercise, or engage someone who can do it for you so that your case can be stated and hopefully addressed.

    Mal.
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  35. #1735
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    Quote Originally Posted by decentespresso View Post
    Very helpful info. So, obviously, every machine we ship has to self-adjust to whatever it's given. No "I live in Australia" setting would tell us much.

    -john
    G'day John

    It actually is worse than that here in Oz in terms of power. Read on if you dare / care.

    Rumour from when my family moved from NSW* to West Oz in 1964: SECWA, our local electricity supplier, had recently bought a pile of secondhand transformers from South Africa which were 260V and they could only be modified down to 250V. Fact: Vic Park was 258V to 264V at the time. Most of our precision gear blew within a couple of months so my dad actually fitted a voltage reducer to our Vic Park house switchboard to take it down to 230V. Most Perth suburbs at the time were still measuring around 255V, and Osram must have made a fortune because they actually made a 260V light bulb for sale in West Oz "at a price" - the only bulbs that did not destroy themselves in a few days. About 10 moves later (civil / safety engineer dad on mining / oil rig projects) in 1972 we moved to Mackay in Qld. We were the only house at one end of a brand new suburb - voltage swings from 450 (yep - they screwed the phases up the day we arrived and started to unpack in our brand new house) down to 245V. Dad bought a large Variac whilst the Qld electricity board processed a several thousand dollar claim for a brand new Wurlitzer electronic organ which happened to be the first thing we plugged into the new house (music while we unpacked was S.O.P.). One huge bang and it launched my mum a few metres backwards. I have seen less electronic damage from a lightning strike (the 450V was constant at a high amperage, lightning is a low current, rapid, one shot event). The electricity board also covered an additional three weeks at a hotel whilst they sorted the power out. An "after complaint / regulation" 160V to 245V random cycle (no joking!) was their best effort until we moved again a year or so later.

    I have also read a couple of technical articles which claim that tinkering with voltage can save the electricity suppliers some money as the house meters actually read more than the provided power. Not my professional area, however I would not be surprised at any power company dirty tricks here in Oz.

    Back to the west. Over the last year in the West I have measured voltages from 210 to 255 at various metro / outer metro (i.e. half of greater Perth including Rockingham is outer metro) locations. Most of them also have cyclic voltage variations over each day however the frequency is very stable. No problem for cheap & nasty switch mode power supplies but heaps of grief for a lot of more expensive gear using better quality power supplies.

    Your "I live in Oz" would only forewarn you that the voltage regulation at too many places is fairly notional. Perhaps a bit of software which senses the voltage at the beginning of the shot and modulates accordingly would be a good move? Not everyone has a variac.


    TampIt


    NSW*: i.e. level3ninja's home turf nowadays where they have been slowly (erratically?) working down from 240V since the '50's. Cannot rush these things whilst the overcharging by privatised power companies keeps their profits up...

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    Quote Originally Posted by decentespresso View Post
    Yes, that is 100% the idea. I posted about the "puck simulator" accessory here on this forum some time ago:
    https://coffeesnobs.com.au/brewing-e...tml#post631924

    Armed with a Bluetooth scale, a 0.2mm basket (will be available for sale soon ~AUD$30) and the espresso calibration program (which is simply an advanced shot), you'd be able to re-create what we have done.


    That's a good insight.

    However, I didn't mean to make you scrape the graphics for the data. Just ask: I'm happy to share the data itself on anything I post.

    Here are three CSV documents showing the three calibration tests at different voltages:
    http://magnatune.com/p/presstests_csv.zip

    Note that these CSV export documents are now created automatically when you save a "god shot", as part of a recent tablet software upgrade I put out.

    -john

    screen 2019-01-15 at 1.50.36 PM.png
    Thanks John! I would have asked for the data at some point, I was just looking for something to do on the train ride home!

    Great that you've incorporated the csv export functionality. Much easier to parse than the old format. I would note that having spaces between the values makes it more readable in text format, but it would be better without them from a data analysis perspective (less steps to clean up the data).

    I knocked together a few plots (colour coded by nominal voltage), one with the raw data and one with a crude calibration (which actually seems quite good).

    Uncalibrated.pngCalibrated.png
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    Quote Originally Posted by MrJack View Post
    would note that having spaces between the values makes it more readable in text format, but it would be better without them from a data analysis perspective (less steps to clean up the data).
    Good suggestion. I've now gone ahead and done that both for the standard CSV export and for the new EEX CSV format that we have developed in partnership with SEP https://www.naked-portafilter.com/sm...esso-profiler/

    was:

    espresso_elapsed, espresso_pressure, espresso_flow, espresso_flow_weight, espresso_temperature_basket, espresso_temperature_mix, espresso_weight
    0.0, 0.0, 0.0, 0.0, 88.0, 88.0, 0.0

    is now:


    espresso_elapsed,espresso_pressure,espresso_flow,e spresso_flow_weight,espresso_temperature_basket,es presso_temperature_mix,espresso_weight
    0.0,0.0,0.0,0.0,88.0,88.0,0.0

    Quote Originally Posted by MrJack View Post
    I knocked together a few plots (colour coded by nominal voltage), one with the raw data and one with a crude calibration (which actually seems quite good).
    That's great news.

    Ray was hoping that a simple calibration based on these charts would work and was about to apply it in a few days.

    He's working on a phase locked loop as part of determining voltage accurately, and once he has that working will be applying a correction in much the same way as you have.

    -john
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  38. #1738
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    Refill kit video

    After nine months of work, we finally have the three components of our refill kit finished and in stock. I made a video yesterday showing how it all works together.

    About half our current customers have purchased the Pro version of our Espresso machine and have been very patient in waiting for us to finally ship these three parts which will allow them to fully plumb their machines in. I'm hoping to start contact next week with all those Pro customers, verifying their current postal address, and also talk to them about the free update pack they should be receiving (of things we've improved since releasing our version 1.0 machine).

    -john

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    Calibrating to reality

    screen 2019-01-17 at 6.32.44 PM.png

    Before we ship an espresso machine to a customer, we always calibrate temperature and pressure at the puck, uniquely for that machine.

    Small physical variation in pressure sensors and temperature sensors are a real thing, which is why we use a Scace 2 https://www.espressoparts.com/scace-...ressure-device to verify that our puck measurements are correct to within 0.1şC.

    I asked Parry to keep track of the calibration numbers that he puts into the firmware for the first 19 machines we shipped of our v1.1 model. I've charted and attached the data here.

    You can see that our pressure sensors don't have much variation, whereas the temperature sensors do need typically 1/2°C of calibration from each other.

    Also note that all temperature and pressure sensors are slightly not as the manufacturer has stated (~1.69şC for temperature, and 1.23 bar for pressure), which is why we calibrated to the Scace.

    I prefer to never trust a manufacturer's specification sheet when we can measure against a known accurate benchmark.

    -john

    screen 2019-01-14 at 6.30.44 PM.png
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  40. #1740
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    Ben's DE1CAFE research setup

    Decent engineer Ben Champion shows us a tour of his working setup.

    He’s aiming to increase the power, control the dry/wet mix and controllability of steam for our upcoming DE1CAFE espresso machine.

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