Gerry wrote:Biggest question: Have you confirmed that shots taste better with pressure profiles other than what would normally happen with a gicleur-limited E-61 or equivalent?

It's sweeter and I think my espresso now can taste closer to how the coffee smells.
So yes, IMHO it does taste 'better' than it did with the unmodified GS/3

But I think the interesting thing here is the different approach to creating (and using) profiles.
The problem is that I have to pay full retail price for all coffee that I use, my palate isn't an educated one and I probably own most of my barista skills to the Robur. We really need to put a system like this in the hands of someone with both good skills and some previous experience with 'hard coded' profiles.

A tread called "Everyone started out as a newbie" made me look up my own newbie questions
and April 2007 I simply had to ask "How are these pressure profiles created?"

The Slayer approach The AP approach with visuals

Procon cmp 7000 pump, are they still selling this pump? it looks to be discontinued, i wanted to get one for my 2 group la marzocco linea that is on its way.


Let me know.


Matt

Hey folks,
very nice developments on this thread.
I'm new in the forum, as I usually have access to the german forum.
Since I'd like to build mi own custom Marzocco based machine, I'm trying to find out more about the EP way of pressure profiling.
I just ordered the MG204.
But I have really no idea how it will be connected to any electronic device.
Maybe I would like to buy a microcontroller sold here in germany called Arturo, by faustino. It comes with a software, thats specially for single circuit Espresso machines, as the rancilio silvia.
It provides several PID channels and the possibility of creating pressure profiles with a Vibrapump.
Now I dont know if I am able to use it for this 24VDC Motor of the MG204 Pump.
Here a link to the mentioned microcontroller: Arturo

I would really appreciate your help.
If you wold be so kind to send me some wiring diagrams of your connections of the gearpumps, and/or the way you connected them to the arduino or manual potentiometers.
Thanks a lot
Kind regards
Ali

The bundle MGFR (MG204 + Crouzet motor) is the easy way as the motor requires 24 VDC and a 0-5V signal to control its speed.

You have probably bought a MG204 + brushed motor, like they use inside Strada. You have to PWM the 24 VDC source to control the motor speed, I think you can do that with any motor drive with adequate power (I think this motor is max 2A).

Márcio.

Hello Márcio,
thank you for the answer.
Could you please tell me some more precise, what I would need to PWM the source?
My knowledge does not reach to these heights of electronical understanding yet.
But I am willing to learn more.
Thank you

I'm not sure either.

I think you have to find some MOSFET, like this.

[quote="darrensandford"]Wow, I read this and my brain says "PIC controller! PID control! Graphic display with profile graph!"

I can see using a PID controller with pressure sensor feedback and programming the PID's ramp/soak feature for declining pressure during a 30 second shot. Of course the PID would have to have seconds, not minutes, in its programming. Most are setup for minutes.

Ali wrote:Hello Márcio,
thank you for the answer.
Could you please tell me some more precise, what I would need to PWM the source?
My knowledge does not reach to these heights of electronical understanding yet.
But I am willing to learn more.
Thank you

PWM between the 24V source and the motor, there are lots of cheap pwms around with potentiometer already attached so manual control is already there

Does anyone know how many teeth the MG204 gears have? I did have it apart once, but didn't think to count at the time - now I want to measure the motor speed from the note it makes.
I'm using a cheap adjustable laptop power supply. This works fine down to 12V, and is one less box, although PWM is better at lower flows.

I did have it hooked up to cheapy pwm and 24v supply, it worked fine but some pressure feedback + pid type calculations would be better. Since then Ive taken it out of my machine and had it hooked it up to an arduino (ruggeduino+rugged motor driver) to have pressure feedback calculations, open the 3way when the pump starts and maybe even volumetric shots, still waiting on a pressure transducer, LCD screen, and sliding potentiometer. Its alot of fun even if it never results in a better cup.