So I'm torn between a GS3 and Linea Mini. I'd love to be able to experiment w flow rate on the gs3 but the price point on lmlm is obviously nicer to the wallet. I know there's a mod for adjusting g pre-infusion but is there one to completely control flow rate on lmlm? And what other mods are available? I've heard of "heavily modded" Linea minis.

Your profile says you already have a gs3?

There's are mods, starting with easier things like drilling and mounting the Alcorn Engineering DotShot timer, and swapping the .8mm stock flow restrictor for a .6mm.

'The Coffee Machinist' offers a package that replicates the functionality of a Slayer with a 4 position electronic paddle. Off, line pressure, needle valve preinfusion, full flow. They so install a flush mounted PID display in the top of the paddle housing. However you'd need to send the machine to him in Australia. Perhaps if you ever go that route contact me and we could look into putting both our units on a pallet, I also live in STL.

Hi from Switzerland,

I just wanted to start a similar thread

My current setup is an ECM Mechanika Slim and a Eureka Perfetto. Now I'm planning on buying a Linea Mini. However, a paddle without a "real" function is not what I'm looking for. Now I'm planning to either do the "Slayer Mod" or replace the rotary with a gear pump (FG304).

Regarding the FG304: I do not need an arduino or other stuff, a manual paddle will do it for now. There is a lot of great information about gear pump modifications from peppersass, assafL and all the others! Based on this post (GS/3 Mod EP "Chimera" - a fully configurable profiling mod for La Marzocco GS/3 AV), I know how to connect the pump, however, what is not clear to me is how the gear pump is automatically activated to fill the steam boiler. Can someone tell me what I need to connect that it will fill automatically? And at what speed/pressure does it fill?

Furthermore, does someone has any recommendations on how to connect the poti to the paddle?

Maybe this mod is harder than I thought

Cheers,
Roman

sluflyer06 wrote:''The Coffee Machinist' offers a package that replicates the functionality of a Slayer with a 4 position electronic paddle. Off, line pressure, needle valve preinfusion, full flow. They so install a flush mounted PID display in the top of the paddle housing. However you'd need to send the machine to him in Australia. Perhaps if you ever go that route contact me and we could look into putting both our units on a pallet, I also live in STL.

There is another school of thought in flow profiling that is exploding onto the scene that differs from the limiting factory of having only the two discrete steps first offered by Slayer seven years ago, and that is one where the whole shot goes through a needle valve from beginning to end, and is thus continuously variable from beginning to end. This is how it's done on the LeLit Bianca, and several of us have made extremely simple mods to our other machines, to use the same kind of needle valve.

I have been wondering if the Mini is uniquely suited to the same kind of mod. The BDB is very suited to this mod, (takes only minutes) and it is similar to the LMLM in that it has a small, temp stable brew boiler, right above the group. It's for sure, the GS/3 is not suited to this mod. The GS/3'ers are resorting to either the old skool, multiple paths like Slayer, or custom controllers running gear pumps driven by stepper motors.

-Peter

I think the Dalla Corte Mina does also has a valve which is digital controllable. I haven't found out what kind of valve it is.

I know someone who installed this one from Burkert to do flow profiling: https://www.burkert.com/en/products/sol ... ves/235995.

That one looks not like a needle valve, but like a diverter, so you can send your flow either through a needle or through the regular path. You do not need a diverter if your whole flow goes through one needle, as the current trend seems to be doing.

-Peter

If you opt for the 6mm flow restrictor (which is used in the PB, for example), the standard pre-infusion time basically becomes mute in the sense that the amount of water flowing through at line pressure for two seconds just... isn't much. I have a friend who left the 8mm flow restrictor, but adjusted the rotary pump to seven bar and had great results. For what reason do you need the profiling? Planning on using different styles of espressos?

A very general view (that may catch some flack) is that you can tweak your machine to do pretty well with light roast espressos, or pretty well with medium roast espressos, etc. Personally, I think part of the beauty of the LMLM is that it is a very simple, but sound machine. As a barista, you control your shot more with grind, dose, distribution, tamp, and time. Iterating through those variables alone can produce tons of different shots. What sort of grinder are you looking to pair with the machine?

I thought pre infusion on Linea Mini is with pump pressure? I'm anyway going to operate the machine from reservoir. I have also read about the .6mm gicleur change.

Very good point with shot time, dose, distribution etc. I drink more and more medium to lighter roasts and don't want to exchange the machine again. And of course I'd like to play with the machine.

Regarding the grinder: I have thought about the Mahlkonig K30 or the Ceado E37S. I don't like the look of the Eureka Atom. Niche single dosing grinder would be another option. Maybe you have some other recommendations?

Lavori wrote:If you opt for the 6mm flow restrictor (which is used in the PB, for example), the standard pre-infusion time basically becomes mute in the sense that the amount of water flowing through at line pressure for two seconds just... isn't much.

Pre-infusion is driven by OPV/resting pressure, this is why it's critical the OPV is set to 12bar on the LMLM. For a real world example, if I flip the paddle when my brew circuit is reading 12bar i get a nice drop of water (i've read about 5g ish) and then a pause, if you draw water from the steam boiler and it initiates a fill cycle you'll see the brew circuit drops low to about 6 bar and if you then pull the paddle you'll get little to no preinfusion water. If the steam boiler refills before a shot, it's good practice to do quick 2 second flush of the group to get the pressure back up before inserting the portafilter.

pcrussell50 wrote:There is another school of thought in flow profiling that is exploding onto the scene that differs from the discrete steps first offered by Slayer seven years ago, and that is one where the whole shot goes through a needle valve from beginning to end, and is thus continuously variable. This is how it's done on the LeLit Bianca, and several of us have made extremely simple mods to our other machines, to use the same kind of needle valve.

I have been wondering if the Mini is uniquely suited to the same kind of mod. The BDB is very suited to this mod, (takes only minutes) and it is similar to the LMLM in that it has a small, temp stable brew boiler, right above the group. It's for sure, the GS/3 is not suited to this mod. The GS/3'ers are resorting to either the old skool, multiple paths like Slayer, or custom controllers running gear pumps driven by stepper motors.

-Peter

by exploding you mean 2 machines I believe (Decent and Bianca). My issue with the manual style like the Lelit is repeatability, because it's so intensely manual you are challenged to attempt to make yourself a robot to get consistent results. What happens when I go out of town for work, now the spouses have to somehow replicate this magic recipe with manual flow control to get good shots. Most of our significant others probably aren't AS into it as we are, though they may enjoy pulling shots every now and then. I also question what the motivation is, what requires this insane level of variability, is it coping with underdeveloped beans? How long are we going to start committing to dial-ing in a bean? With that many variables in play between time, temperature, dose, ratio, and now infinite variable flow profiles, it could be a couple dozen shots before you even start to close in on the perfect combination.