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  • Modded Linea Mini just arrived

    I first made contact with Rick Bond (aka site sponsor the Coffee Machinist) in early January. I was pretty intrigued by his Linea Mini modifications. A Slayer style pre-brew or preinfusion has always been of interest to me... I like the texture of ristretto shots (I'm a dinosaur I know) and felt that longer shots with that sort of texture as well as the potential for more tasty shots because of the ability to grind finer with that style of pre-brew would be a great combination. It was really good working with Rick as I had many other custom features that I wanted. I like my steam wand to the left, so Rick managed to reroute all of the tubing, I really wanted a shot timer (I'd been spoilt by my last machine, a Profitec Pro 700), and I wanted to be able to reduce pre-brew flow rate to something like 1.5 grams per second which was achieved by fitting a smaller diameter 0.6mm gicleur. The shot timer in particular is a work of art, having been beautifully integrated into the paddle housing.

    I've only had the machine for a couple of days but it's clear that it's a really capable machine. Commercial strength steaming is an eye opener having come from three prosumer machines. I'll need to improve my steaming capabilities to handle a full 2 bar of steam pressure (milk was literally being blown out of my small milk jug) and so have dialled pressure down to 1.6 bar. I spent about an hour and a half checking brew temperature with my Scace and the integrated group head is extremely temperature stable.

    Other things that delight about this machine/setup:
    - The Linea Mini looks really amazing in the flesh (much better than photos)... the stainless panelling is thicker and more robust than I had expected;
    - The drip tray has a little funnel extending out of the back middle which makes it really easy to empty;
    - La Marzocco spouted portafilters are deep enough to accommodate triple baskets;
    - The paddle is super solid and feels wonderful - I understand that Rick does work on the paddle as consensus suggests that LM sends Linea Minis out with paddles that are much to stiff.

    Things that are not delightful:
    - The little wheel that drives the potentiometer/PID for control of the brew temp is way off... I found that it suggests that brew temp is a full four degrees celsius less than what the Scace is measuring. The only upside is that it is consistently four degrees off so once one is aware it's fine... however if I didn't have a Scace I'd feel very confused;
    - The steam and hot water knobs have LM fleur de lys symbols on them, but they are not aligned vertical when the knobs are in their off positions.

    Currently I'm running pre-brew at 2 bar for 20 seconds, with first drops of espresso hitting the cup at about 18 seconds followed by 22 seconds of 9 bar extraction. Brew ratio is 1:1. Extractions are very clean and tasty with grind only slightly finer than what I had been using on the Profitec.

    All in all, this has been a great purchase. Rick's done a great job.
    Attached Files

  • #2
    Rick has to Melbourne's #1 when it comes to coffee machine mods. LEGEND.

    Great setup there - enjoy

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    • #3
      Nice write up. What did you do with the Profitec?

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      • #4
        Originally posted by herzog View Post
        Nice write up. What did you do with the Profitec?
        Sold to a friend of mine... it was and is a wonderful machine.

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        • #5
          Congrats on the machine, it looks fantastic. I have recently ordered one through Rick. Great mods that have been done to yours. Love the shot timer.
          I too think they look a lot better in the flesh (I have also gone with the stainless steel). As you say the stainless steel panels are so thick, and it just oozes quality.

          I'd be interested to hear your thoughts on the difference you notice in the shots you pull using the preinfussion as apposed to just going to full pressure.

          One of the reasons I wanted to go through Rick is if I want to do the modified paddle upgrade later down the track.

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          • #6
            Originally posted by Davie View Post
            I'd be interested to hear your thoughts on the difference you notice in the shots you pull using the preinfussion as apposed to just going to full pressure.

            One of the reasons I wanted to go through Rick is if I want to do the modified paddle upgrade later down the track.
            Great question. I have an initial answer for you but there are so many variables that it's not at all a definitive response. Yesterday I roasted some washed Ethiopian Sidamo Bulga for pour over at work. Thought I'd run it through the Linea both at full pressure and with preinfusion. The results are not surprising... with 20 seconds of preinfusion and a finer grind (such that the brew ratios are the same) the coffee is noticeably less acidic, thicker in texture and a little sweeter. Straight to full pressure with a coarser grind produced more citrus notes. Both shots were great, it's all about your preferences. It's important to note that Rick adds a spring-loaded pre-infusion chamber so that even when I go straight to full pressure the modded version still has significantly more preinfusion time than the stock Linea Mini.

            One other thing that I didn't note in my original post is that the small brew boiler really does adjust very quickly. Brew temp reaches a new stable temperature in at most two minutes... that was the interval I was using to measure... so with my preshot routine I expect that the brew temperature is truly adjustable shot to shot.

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            • #7
              That is AWESOME. First machine for a while that has me thinking about upgrade

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              • #8
                They really are an amazing machine. Rick's mod turns a 5.5/10 into a good 8.5. Sample one if you can....

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                • #9
                  Thanks heaps for the write up kwantfm!

                  Thanks also for your confidence in the preinfusion system, patience during the lead time and latitude to let me do my thing with the shot timer etc! It has been a pleasure putting this 'mini with the lot' together for you.

                  The paddle feel is something I work alot on. The stock setup is super stiff, and I find the hard edges from the bakelite mouldings particularly offensive. Bakelite is a great material to the touch, but it has to be SMOOTH! So that's the first step. The paddle itself rides on thick teflon friction pads, which are locked down with a double nut and some spring washers. I back off the tension, change the grease to something with lower viscosity, and change the spring washers to a star washer, to lessen the chances of the washer turning against the nut. This may need to be tensioned up slightly down the line but I figure it's better that it feel right from day one.

                  Some observations from my end on the temperature wheel - These come calibrated from the factory (you can see the notes from the factory techs in sharpie), but I sometimes need to make my own 'adjustment' - this consists of pulling the wheel off the potentiometer, taking an average of a few temperature measurements at the group and re-setting the position of the wheel. Kinda crude, but I find it works.

                  I have a theory why you're seeing higher temperatures on the scace device than the wheel position indicates, and it comes down to flow rates (again!). The standard gicleur in the scace measures from memory 0.3mm. When translated to flow rate from the group at 9 bar pressure, this is much higher than we'd be typically extracting an espresso at, especially with my (and yours it seems) preference to ristretto style extractions.

                  This is where Newton's law of cooling plays a part. If you lower the flow rate down to a 1:1 ratio when taking measurements of temperature at the 'puck', you would see a significant drop due to the fact that heat is being lost in the portafilter/basket due to the increased dwell time.

                  For a few years now I have ditched the standard fixed jet on the scace in favour of an adjustable needle valve. This is how I've set the calibration on your machine and the number should correlate once you get down to a more realistic flow rate when measuring temperature. I also semi regularly calibrate the probe to the meter in a boiling water bath.

                  If you do get more data on the temperature offset at different flow rates, I'd be keen to know your findings. I use a mini gear puller to remove the dial from the potentiometer shaft but I think it could be done easy enough by hand.

                  Yeah the steam pressure takes some getting used to! Do I see a different steam tip in one of those photos? What's the hole pattern/size?

                  The steam knob insert alignment - yeah a few people have commented on that but I gotta say it doesn't bother me in the slightest! They are threaded, so what I'd suggest as a fix is to take them out, and carefully score the plastic thread of the white insert with a blade, against the direction of the thread. This would give enough friction to hold them in place at any angle. Maybe?

                  Again, thanks and I wish you many spectacular shots. They really are a great little machine. Super quiet as well which I really like.

                  -Rick

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                  • #10
                    Thanks Rick, so sounds like I should check temperature using pre-brew right?

                    Very observant on the steam tip... it's a Sproline Foam Knife which I've had plenty of luck with in the past... I might try the stock tip (I swapped it for the Foam Knife immediately).

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                    • #11
                      Congrats. What an amazing difference a "Rick" can make !!

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                      • #12
                        Stock steam tip is fabulous...

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                        • #13
                          Agreed, the stock tip is great. The steam quantity/quality is up there with a full size LM commercial, one thing LM have always excelled at. The dedicated anti-vac, high boiler capacity/ pressure and huge diameter pipe also help, of course!

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                          • #14
                            Modded Linea Mini just arrived

                            Originally posted by coffee_machinist View Post
                            Agreed, the stock tip is great. The steam quantity/quality is up there with a full size LM commercial, one thing LM have always excelled at. The dedicated anti-vac, high boiler capacity/ pressure and huge diameter pipe also help, of course!
                            Since picking mine up from Chris at Talk Coffee (modified by Rick prior to purchase) I have discovered that this is not only the most powerful steamer if have ever used but also the easiest to make silky milk with. Amazing. Tip just below the surface and go for it. About 8 seconds later (or so it seems) and it's all over. A quick swirl and good to go!!



                            Thanks go to both Chris and Rick. Lovely machine and great service as always from both, especially to Chris for opening the shop for me to pick up at a time when he wouldn't normally be open.

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                            • #15
                              Is that the La Marzocco Lux Grinder with that Luke?

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