Decent Espresso Machines (DE1) - Any thoughts?

[tinkerfrog]

[ATTACH=CONFIG]20932[/ATTACH]

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

[>decentespresso]

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.

[Lyrebird]

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.

[gc]

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?

[Dimal]

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

Mal.

[gc]

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

Mal.

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

[>decentespresso]

Decent Suitcase v2



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

[>decentespresso]

v1.1 Shipping Update



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

[>decentespresso]

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.

[>decentespresso]

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

[>decentespresso]

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

[TampIt]

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

[level3ninja]

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.

[>decentespresso]

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.

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

[>decentespresso]

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