Quickmill QM67 flow profiling upgrade

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#1: Post by mckolit »

My original thread has been closed due to age. Quickmill QM67 Evo on the way I recently purchased a flow control device. Arriving in a week. I bought the coffee sensor one. Can't wait. I'm watching all I can on flow profiling in preparation. I'm planning on going with a slayer style shot to start things off and then try the ones from the whole latte love YouTube vids.

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mckolit (original poster)

#2: Post by mckolit (original poster) »

Getting the standard flow rate of my QM67. Three shots at 20 seconds:
151.5 grams
153.3 grams
148.8 grams
151.2 grams average
So 7.56 grams a second.
I've tuned down the opv to 6.5 bars. Guess I'll have to raise it back up to 9 bars when I install the flow control device.

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mckolit (original poster)

#3: Post by mckolit (original poster) »

Yes! Package arrived today from DHL. Got my tools ready, time to crack this baby open.


#4: Post by salvia »

a hammer... :shock:

Does anyone know if the Lelit flow control assembly (the one with the paddle from the Bianca) will fit one a QM67?
One of the reviews on 1st Line's site mentions it working on a Lucca M58, which is a QuickMill E61, so maybe?
https://www.1st-line.com/buy/lelit-grou ... -grouphead

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mckolit (original poster)

#5: Post by mckolit (original poster) replying to salvia »

Just in case? :D Not sure if there would be issues fitting a lelit device. I went with the coffee sensor cuz it's a little cheaper than the quickmill one and they are known to fit. In theory, they all should work since they're all made for e61 groupheads. An issue you would run into would be the wood paddle from the Bianca will get in the way. Right now, the full range is two full turns on my machine.

All the parts waiting to be installed.

Thanks to some YouTube vids, install went quickly. Took 15 minutes. Now to run some flow tests.

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mckolit (original poster)

#6: Post by mckolit (original poster) »

Ran flow rate tests
1/4 turn 1.10 grams a second
1/2 turn 3.59 grams a second
3/4 turn 5.52 grams a second
1 turn 6.26 grams a second
Then a weird thing happened. At 1 1/4 turn went back down to 5.6 grams a second. 1 1/2 turns was 6.26 grams a second.
1 3/4 turn 7.33 grams a second.
I'll run the flow test again tomorrow to see if 1 1/4 and 1 1/2 turns change.
After testing had to get a shot in. 18 grams in, aimed for 36 or so grams out.
Started the shot at 1/4 turn. First drops appeared around 20 seconds. I opened it up 1 3/4 turns until the end of the shot at 50 seconds. Didn't look at the pressure gauge at all. Gotta look at that thing next time I run a shot. I have the brew boiler at 204. Shot was very bright. Honduras Copan organic from Bodhi Leaf Coffee roasted to City+/Full City range (maybe).


#7: Post by Marmot »

I think you have to start measuring the flow rate some time after water comes out of the group. In the E61 there is a small chamber filling up before water comes out. There is probably some variation to the time the first water comes out from shot to shot.

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mckolit (original poster)

#8: Post by mckolit (original poster) replying to Marmot »

For each quarter turn I ran each test three times at 20 seconds and got the average. The two results at 1 1/4 and 1 1/2 were the weird ones. On my machine, even before I put the coffee sensor kit in, water would come out right away.
I'll run more tests today and see if it's just a thing with my machine.
I was fortunate to win a giveaway by Jackrabbit coffee of one pound of their espresso beans. Can't wait to run some tests with those beans.

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mckolit (original poster)

#9: Post by mckolit (original poster) »

I think I'm done testing shots for now.

Reran the flow tests and discovered that I mixed up some results. With the knob of the device being able to pivot I got mixed up with the turns. I thought max number of turns was two full turns. It actually maxes at just passed 1 1/4 turns. Oops.
So new results were
1 turn 6.7 grams a second
1 1/4 turn 7.1 grams a second
Each time running the test 3 times per station. Each time the third shot would be significantly lighter than the previous shots. Turns out the flow slowed down while the boiler was heating up.
At max output, it was 140+ grams. Each normal shot is only around 30+ grams so there's a bunch more water coming through. I have the boiler set to 204 right now. It would go all the way down to 197 before climbing back up. I timed it and took the machine 1 minute 30 seconds to rebound. Usually not an issue for me during my normal routine.


#10: Post by sambuist »

so it seems like you are doing a long low pressure infusion (20 sec to 1st drop). this is kind of a slayer shot i think. is it tasting better that without the flow control?