I'm wondering how this device would affect the Lelit Mara X's preinfusion function. Trusted sources have advised not to bother with it. I still want to mess with one.

GC7 wrote:Can you post the flow rates (ml/sec or 10 seconds) at fully open and each 1/4 turn of the knob to slow flow? I'm curious to see if this device can reproduce profiles posted using other devices. Thanks.

I use the hex nut under the valve handle to reference my adjustments per 360 degrees. Thankfully I was able to set the handle right in line with the middle of a edge of the hex, so visual divisions of the rotation are pretty easy! The first point is 30 degrees, the next edge is 60, the next point is 90, etc. Here are my findings so far:

360deg: basically full flow, between 7.5-8.5 mL/sec
180deg: restricted but still high flow, about 6 mL/sec
90deg: restricted flow, about 5-5.5 mL/sec
30deg: slow flow, about 4.5 mL/sec
15deg: slow flow, about 3-3.5 mL/sec
~5deg: a trickle at 1.5 mL/sec

For espresso I don't have much need for going beyond those first 90 degrees of rotation. I open it up to about 180 for backflushing.

I've started getting acquainted to this by trying to reproduce Slayer style shots, since I'm quite familiar with them from my time at Prima. I'll set the valve to about 10-15 degrees, aiming to see drips after 20-30 seconds. Then I will open it up to 90+ degrees to increase flow rate until within about 10 grams of my desired yield, at which time I'll taper it back to about 30 degrees until complete. I'm still getting a feel for this, but those shots do seem to perform and taste like the Slayer shots I've been familiar with.

Thank you so much. I'm happy to see you can get a sort of linear gradient across the range of motion of the handle. That's good data for the QM device and incentive to try it on my QM DB.

Received mine today and installed it immediately. So far I'm disappointed. Like the person above me said, it won't work like the way you thought it would work. Once I turn pass 1/4 turn, it just shoot up to 9 bars and stay there unless I shut off the valve completely

Alright so, I played around with mine a good bit this morning and this afternoon. First things first, I put the stiffer spring, the one that ships with the new profile mushroom, in the grouphead as well(I had been trying it with the stock spring for curiousity)

My bad on not having hard numbers for flow rate manipulation for free flowing water from the group. However, its obvious visually you are able to go from absolutely no flow, to gradually more and more, even way more than the usual E61 would give you.

In actual use. I have my knob fully closed off, to be set at 9 oclock. So like, on the left side of the grouphead. And for brewing espresso, I dont need to go past a 90degree turn, or there abouts.

Heres what I CAN say. You absolutely can introduce a really slow, low pressure preinfusion, of around 2-4bar. Getting it exactly at a specific target finer than that, say you wanted 3.7bar, is probably impossible. But with proper manipulation, I could keep the flow there indefinitely. Keeping in mind, to stay at that flow rate past 30 seconds, the knob is nearly closed off.

All of adjustment seems to be in that first 1/4turn, from roughly 9oclock to roughly 6oclock. I was able to produce, somewhat repeatably, the slayer style shot, long preinfuse somewhere around 3, ramp up to 9ish, let it flow a bit, and start to bring it back down. But again, you will basically be at the point where the knob is closed off. What Im trying to say, is the action of the valve, the turning of the valve, does NOT equal a linear rise and fall in pressure.

I would like there to be more granularity to the control. Maybe thats not possible with this design, IDK, Im going to try and watch some videos of those with the other brands of E61 flow control devices and see what theyre doing.

Its decieving in that, you can turn the thing like what, two full rotations to fully open, yet once you have finished pre-infusion and have let it ramp up to ~9bar, the amount of travel in the knob to lower the pressure back down for the finish of the shot, is tiny. It really is the last little bit before the knob is closed off that youre almost pushing against to get the pressure to drop a little lower.



Im sorry for the somewhat rambling nature of the post, Im very in two places at once. On the one hand, in essence, I can pull the slayer style shot with some degree of repetability. That was the goal mostly. But I think I expected much more travel in the handle to have more of an effect. I certainly didnt expect Strada EP levels of granularity across the travel of the valve, but, and this could entirely be my fault for simply not knowing, I didnt expect all the manipulation to be within what equates to between 7 and 9 on a clockface.

Question for those that have installed it: Would it help the usability to have a longer knob or handle on the device? It seems that if we're looking at a 90 degree arc to control the flow then there's no need to clear the back of the group and a longer lever, like the Lelit version, or even longer, would help controllability. BTW the Lelit version is limited to 200 degrees (generous 1/2 turn) according to the manual. The Quick Mill knob is threaded in -- does anyone know the thread size ? I'd like to pickup or fabricate a longer knob while I wait for mine to arrive. Thanks!

JmanEspresso wrote:Alright so, I played around with mine a good bit this morning and this afternoon.

All of adjustment seems to be in that first 1/4turn, from roughly 9oclock to roughly 6oclock.

But I think I expected much more travel in the handle to have more of an effect.

I didnt expect all the manipulation to be within what equates to between 7 and 9 on a clockface.

Jeff

It would be really helpful if you would do the experiment and measure the flow rate (ml/ sec over a 20 second time frame or grams H2O per second over 20 seconds) at each knob position. That graph would show the effectiveness of the device to produce a flow gradient.

OK, Ill do it and report back

With my Duetto plumbed in, I can preinfuse at line pressure all day. This is about 3.5 bar at my house, and that pressure hasn't changed over the last decade. So, what I'm hoping to take advantage of with the flow control mod is the ability to ramp up slowly and ramp back down for the last third or so of the shot. I'm curious to know if the group pressure gauge is useful. I guess I'll find out later this week.

Ok I got a hang of this thing now but for some reason my brew pressure at group head never reach 9 bars. 8.5 bars is my max. My machine is plumbed in so I will try to adjust brew pressure up a bit to see any change at the group head