Someone's custom build espresso machine - Page 2

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3phase

#11: Post by 3phase »

Quick video of software testing. Running a simple profile with a flow-controlled preinfusion and a flat 6 bar shot through a "puck simulator", made from a spare basket and a needle valve. Still a lot to do, but it's almost usable now.

Top plot is pressure and flow, bottom is temperatures (although the heaters were turned off for filming)

Sorry about the noise, for now I'm powering the pump off a 1u rack mount power supply with a loud fan.

harleyujoe

#12: Post by harleyujoe »

I may just have wait little longer to purchase new Espresso machine..You have caught my eye on progress..

Enjoy your project and keep us informed..

3phase

#13: Post by 3phase »

More progress!

Blog post about flow estimation, flow control and pressure control:
https://build-its-inprogress.blogspot.c ... mware.html

And here's a video of actually making some espresso and controlling the machine through a touch screen gui:
Now that everything's mostly working it's time to start designing the real machine.

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redbone

#14: Post by redbone »

Interesting machine concept, kudos. Now you need a good grinder project. May I recommend a DRM hybrid. A little ditty about DRM Srl hybrid burr type.. Willing to test prototypes.
Between order and chaos there is espresso.
Semper discens.


Rob
LMWDP #549

longpvo

#15: Post by longpvo »

I have a feeling that top end non-commercial machines of the near future are going to move away from vibratory Ukla pumps and be fitted with a miniature rotary pump with a DC motor like Fluid-o-Tech GA series (currently fitted on Crem One 2B LFPP and possibly the recent VBM Domobar Super Digital/Electronic)

And that begs the question, is controlling flow rate / pump pressure with a rotary & dc motor more reliable than that of a vibratory pump? Like what Breville is doing by waveform manipulation of the power to the pump.

I don't want to steer this post into another conversation but I wonder why the Decent DE1 doesn't use something like the mentioned miniature rotary pump. If I read the Fluid-o-Tech spec sheet correctly, it can easily output the water gush of a Londinium, not that one needs it, but since they start tapping into pour over, and I remember correctly they acknowledged that the new XXL is more capable of serving larger pour over batch.

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Jeff
Team HB

#16: Post by Jeff »

One of the challenges is accurately measuring flow rate at low rates and being able to moderate it quickly. The DE1 does this by modeling the flow that would result by a single, pump stroke at the current pressure. Early DE1s had a flow meter, but it was found to be insufficient for the desired accuracy and speed of control.

The XXL, from what I understand, plans to address the flash-heating demands of prolonged flow through higher-power heaters (that require more than a 120 V, 15 A circuit can provide). This is similar to flash steamers being available for 230 V, but being anemic in 120 V markets.

Capuchin Monk

#17: Post by Capuchin Monk »

3phase wrote:Now that everything's mostly working it's time to start designing the real machine.
Can't wait to see "Order" click button.

crwper

#18: Post by crwper »

A couple of thoughts about the heater:

First, I'm wondering if you could use a heater with several sections to avoid the overheating issues. In the first section, you have relatively cold water entering the heater, so you can drive it fairly hard without risking boiling. In subsequent sections, the heater would be kept progressively closer to the desired temperature so that extreme gradients are avoided. This would allow you to get closer to the target temperature with a shorter total length over which the water is heated.

Second, would it be beneficial to add a section similar to an epoxy mixing nozzle to generate turbulent flow? This would help make the temperature of the water more uniform, but I'm not sure at what cost.

tinman143

#19: Post by tinman143 »

Love when I see home hacks. So much winning here