ECM Synchronika with flow control pressure gauge faulty?

#1: Post by **Poskantor** » August 15th, 2022, 5:06 pm

Hi, I recently got a new ecm synchronika with flow control. I have tested the flow at 1/4, 1/2 turn etc and it is working as intended. I am also pulling tasty shots. My issue is with the flow control pressure gauge. The gauge will always shoot up to about 9 bars and decline slightly from there for the duration of the shot, regardless of the flow. Even with a 20 sec pre-infuse at a 1/4 turn, the dial will show as 9 bars or so. Anyone experienced this issue?

#2: Post by **Jeff** » August 15th, 2022, 7:05 pm

A flow-control kit adds a variable restriction into the path that feeds the basket. It does not directly control flow nor does it directly control pressure. The flow across a restriction will be related to the pressure across it. The bigger the difference (such as an empty basket) the greater the flow. Once the basket is close to pump pressure, the position of the valve, will have little effect, until almost closed. If you think about it, no matter the position of the valve (except for completely closed), a blind basket will eventually reach 9 bar (or whatever your pump pressure is).

A practical example is An Even MORE Considered Approach to E61 Flow Control (now with video)

#3: Post by **PIXIllate** » August 15th, 2022, 7:35 pm

Flow creates pressure (regardless of the input flow rate as the input space is finite) and then pressure restricts flow. It's not a direct 1:1 relationship.

There are some very clear phases in the example of espresso as you initially introduce water into the air above the puck, then into the puck itself, then pressure rises. After that you get flow out of the puck, at a certain point enough of the soluble material in the puck erodes into your cup and then the flow is no longer as restricted and therefore speeds up.

It takes some time to get a feel for how it all interacts.

#4: Post by **JRising** » August 16th, 2022, 8:11 am

If what you're saying is that your flow control can not close off the flow or reduce it to the point where you want it for pre-infusion, then make sure to point that out... If the gauge shows 9 Bar when the flow control is neither closed off nor very close to closed off, then it's normal. As long as the gauge is able to go to 9 and also to 0, it sound like the gauge works well.

August 16th, 2022, 1:06 pm

Thanks, yes it does go to 0-9 (12 the the blind basket). Where I'm have trouble is that I cannot seem to replicate videos like WLL, where they maintain 2 bars, then up to 9, back to 4 etc. while I can replicate the flow and timing of those shots, my gauge will generally read 7-9 bars

#6: Post by **Jeff** » August 16th, 2022, 1:13 pm

My suggestion would be to work with Pixillate's profiling technique An Even MORE Considered Approach to E61 Flow Control (now with video to start. Many times a vendor's videos are more about selling machines than they are representing current practice.

You may need to check the adjustment of your valve. At least in my experience with profiling on a different system, being able to close off flow is more important than the last 10% or whatever of basket-fill rate.

Link added for clarity

August 16th, 2022, 5:10 pm

pixxilate profiling technique? Would you have a link? I can't find anything on that. Cheers

#8: Post by **PIXIllate** » August 16th, 2022, 5:17 pm

The link in post #2 above.