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'Pressure Profiling' With The Fluid-O-Tech TMFR Pump - Or, Wholesale Copying Greg Scace's Ideas - Page 25

Postby Carneiro on Tue Jan 03, 2012 1:51 pm

Interesting thing about the bypass.

Strada uses the gicleur indeed and I think if GS/3 or any other machine will be plumbed in the glicleur helps to limit the flow at the start, considering line pressure and possible high flow.

Márcio.
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Postby shadowfax on Tue Jan 03, 2012 1:58 pm

Carneiro wrote:Strada uses the gicleur indeed and I think if GS/3 or any other machine will be plumbed in the glicleur helps to limit the flow at the start, considering line pressure and possible high flow.

There's no question that you need a gicleur. If you leave it off you'll find that the machine makes some really awful noise when flushing and preinfusing, because the lack of a gicleur (effectively, an orifice of ~1.2mm, what the opening in the solenoid face of the TL30 tube is) means that there's enough of a pressure drop that the water in the heat exchanger feed to the boiler gets to flash boil in the tube—at least, I'm pretty sure that's what's going on from my armchair reasoning based on the sound and where it seems to emanate from. And it is awfully annoying, at least to me. In my experience you shouldn't go wider than 0.9mm on the orifice if you want to avoid this noise. I use somewhere in the 0.7-0.8mm range myself (sorry, I can't remember what it is exactly), as I feel this lets you have a soft infusion but allows you to get control of the pressure somewhat sooner, say by about 2-3 seconds.
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Postby Jacob on Thu Jan 05, 2012 4:42 pm

Things are coming together and I should be able to connect and test run the new motor as it is :D



Display:

Row 1, Column 1: state (idle/fill) or current shot shot-time while brewing.
Row 2, Column 1: Last shot-time (if any) for brew-activations longer than 10 sec.

Additional info while brewing:

Row 1, Column 2: number of flow meter clicks (I like - it's a keeper).
Row 2, Column 2: duration of last click-interval in milliseconds.

Row 1, Column 3: PWM-output for the motor ("preinfusion value" to "max. value" here 36-255).
Row 2, Column 3: Potentiometer input (0-1023) which is converted to the above PWM output.
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Postby mitch236 on Thu Jan 05, 2012 4:59 pm

So if what I'm seeing is correct, you can use the total flowmeter clicks to determine shot volume and click interval to control the flow rate. This is very cool! Are you using the stock LM flowmeter? I didn't realize it provided such fine detail.
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Postby Jacob on Thu Jan 05, 2012 5:16 pm

Correct! And it's the stock LM flowmeter (used by the GS3 at the same time).

In the video the pressure really builds up at 7 sec. (long click-duration).
At that time I have already used 55 out of 100 clicks of water :shock:
(my std. dose just happens to be 100 clicks).
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Postby mitch236 on Thu Jan 05, 2012 5:28 pm

That's really good news! I can't wait to have this running on my machine.
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Postby Jacob on Thu Jan 05, 2012 6:35 pm

Just to clear any misunderstandings:
I'm only registering and showing the duration between clicks (the output is not adjusted in any way as it is)!
The new pump/motor is not connected! But the output numbers are for real and pin 9 is hot :D
This is nothing more than a more informative version of the most simple analog Potentiometer control when it comes to functionality.
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Postby Maciolus on Fri Jan 06, 2012 3:32 am

You can avoid drilling the bypass valve by adding an external regulated bypass circut to your pump.

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Postby Jacob on Mon Jan 16, 2012 7:32 pm

Still have a few things to do before I'm able to hook up the new pump/motor - meanwhile

Imitating auto profiling ruled by flow.
From "preinfusion value" to "max. value" (here 36-252) the flow meter click-interval is simply divided by 2!


Display:
Info while idle or filling the steam boiler:
Row 1, Column 1: state (idle/fill).
For brew-activations longer than 10 sec. (if any):
Row 2, Column 1: Last shot shot-time.
Row 1, Column 2: Last shot average flow meter click-interval in milliseconds.
Row 2, Column 2: Last shot max. flow meter click-interval in milliseconds.
Info while brewing:
Row 1, Column 1: current shot shot-time.
Row 2, Column 1: Last shot shot-time (if any).
Row 1, Column 2: current shot number of flow meter clicks.
Row 2, Column 2: current shot duration of last click-interval in milliseconds.
Row 1, Column 3: PWM-output for the motor ("preinfusion value" to "max. value" here 36-252).
Row 2, Column 3: User compensation (using a rotary encoder).

Image

- I probably need a separate flush function!
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Postby dsc on Mon Jan 16, 2012 7:50 pm

Out of curiosity I've decided to have a look at the HB forums and I can't believe this thread is still going! :D craaaaazy espresso geeks!;) Good to see someone else messing around with the idea, especially with the new pump, should simplify things a lot.

Regards,
dsc.
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