La San Marco single group lever

Posted on January 7th, 2016

converted La San Marco single group lever

Dual boiler, dual PID commercial lever beast!

This beast started out life as a La San Marco 85 series, single group volumetric heat exchanger. I bought it last year as a fixer upper, the boiler was over filling and it needed a general going over. 9 months or so later and it’s a very different machine to the one that came in!

Turns out the over filling problem was a fractured heat exchanger, so that ruled out keeping the machine conventional – the heat exchanger would have to be decommissioned, capped off and become part of the steam boiler volume – I didn’t like the chances of a successful repair.

At that point it became a total strip down, and while I had the bare chassis on the bench, I started playing around with the possibility of fitting a lever group that I had spare. With an extra cross member in the chassis, it would totally work! So, off to see my mate Gonz who worked his magic and welded in a cross piece to take half the group flange. The group was already fitted with cartridge heaters, from back in the days of the Quick Mill Achille testing with Talk Coffee, so why not take advantage of that? Then, why not add some extra precision with a dedicated brew boiler as well? Yep, it would fit with a bit of wrangling. I also adapted a small volume heat exchanger into the existing steam boiler to provide pre-heated water to the brew boiler. Serious overkill at this point but why the heck not?!

So, this ended up being the most advanced lever machine I’ve built to date, with a PID controlling the group and a PID controlling a dedicated brew boiler just behind it, temperature control is phenomenal. By tweaking the two set points, you can even control the shape of the traditional lever temperature profile.

The original boiler is slightly under-specced at 1700W, but it allows the total machine wattage to stay at approx. 10 amp draw, with 600W in the brew boiler and 200 in the group. It takes a while to reach 1.5 bar, the group is hot well before then – but is ready to go after 25 min approx. and steam pressure is never an issue due to the huge volume for a single group, and added insulation.

It’s plumbed in only, as the line pressure primes the brewing circuit and is used for pre-infusion. The spring installed in the group (new of course) generates 10 bar peak pressure. It’s a delight to use and pulls wonderful shots. I’m mad to sell it, but that’s the reality of running a business, I can’t hang on to everything!

Summary of work done:

solved issue with heat exchanger crack
entirely new brewing system – group, boiler, pre-heater, PID control X2.
new autofill controller, SSRs, wiring as required.
rebuilt all existing valves, plumbing.
powdercoat exterior panels in electric blue hammertone (bold, I know, but it looks stunning!)

It’s probably the most advanced lever machine in the world, in terms of temperature control (at the time of writing – 2016). Offers will be considered. I am in the process of finalising fitment of the front panel, as it was never intended to cover a lever group. Once that’s done she’s ready to go, will not take me long!

Linea Mini paddle modification

Posted on January 6th, 2016

La Marzocco Linea Mini paddle modification

enabling the true function of the Manual Paddle

As usual, there are aspects of any piece of equipment that can be improved. My main gripe with the Linea Mini is that as standard, the paddle switch is not a ‘real’ paddle switch.

Let me explain – the original MP ‘mechanical paddle’ group is much loved by baristas for the control it allows over the pre-infusion phase of espresso brewing. The mechanical nature of the group allows the water flow to be turned on first at a lower, or ‘line’ pressure – this is simply the water pressure present in the mains and through the boiler/group, usually around 3 Bar. When the paddle reaches the end of it’s travel, the pump is engaged, and full brewing pressure (around 9 bar) is applied to the coffee. This two stage operation allows a skilled barista to perfect each shot by allowing the most critical first stage, where we want an even saturation of the coffee bed, to happen at a lower pressure. This improves the chances of the coffee puck saturating evenly, giving us a tastier shot.

So, a Mechanical Paddle group is a good thing in terms of control, but, being mechanical, there is a down side. It’s relatively complex to make and thus expensive, and, requires fairly regular replacement of o-ring seals. La Marzocco chose to fit a paddle switch to the Linea Mini, but the important distinction here is that it does not operate a mechanical valve, but a single microswitch which engages the water flow and the pump, practically simultaneously. Thus, the ethos of the paddle is lost because there is no first stage. It doesn’t matter how you move it, quickly or slowly, the result is the same. All this is not to say that it doesn’t work – clearly it does, and well, we just lose out on control over the infusion process. Perhaps La Marzocco chose this for reasons of simplicity – my argument would be all well and good, but if there is a paddle switch present, the expectation is that it works like a real one.

Well, we can make that happen! On the pump outlet I’ve added an extra solenoid with an adjustable needle valve, that is switched on as soon as the paddle is out of it’s stop position. This allows the first stage of the paddle’s movement to replicate the line pressure stage of a mechanical paddle group. In fact, the pressure can be set internally by adjusting the needle valve setting to give whatever pressure is desired for the pre-infusion phase.

Then when the standard microswitch is engaged mid-way through the travel, the bypass solenoid is switched off and the pump comes to full pressure. In addition I’ve added a spring loaded pre-infusion cylinder to the group to further soften out the pressure ramp-up and decline. The group pressure control ends up being a hybrid of Slayer, Kees van der Westen Speedster and La Marzocco Mechanical Paddle – with the best of all worlds. All electric, no seals to replace and fully adjustable. I’m very happy with the result!

Summary of the modification:

two-stage operation with adjustable ‘line’ pressure
spring-loaded chamber further smooths out pressure ramp-up
All electric, no seals to wear out
works in tank mode or plumbed in, with adjustment of needle valve accordingly
hybrid of Slayer, Speedster and La Marzocco pre-infusion systems
paddle action refined for perfect smoothness and feel

At this stage the installed modification is only available for machines brought to my workshop, and there are no plans to distribute a kit as modifications of factory parts, plumbing and electrical connections are required. If you are confident to handle this work as a DIY install, please contact me for pricing and availability. Alternatively you could contact a trusted technician local to you to perform the install work with my instructions. The modification is available for both 230V and 110V machines.

SOLD – Kees van der Westen Mistral

Posted on June 16th, 2015

Mistral machine no. 32

Kees van der Westen

cm20150603_Kees-van-der-westen---Mistral-Duette-side-V1

Complete nuts and bolts rebuild – new legs, chassis powdercoat, and full re-polish of panels. Every gasket and valve replaced. Over a year part time on the project at this stage!
New coffee boiler.
Insulated steam boiler.
A total of three PIDs, one for the coffee boiler and one per group cap via cartridge elements. Steam is pstat/SSR.
Power is 25 Amp single phase, about 5 amps more than original.
Steam valves converted to lever type, one lock-on direction forward and momentary purge backward. Valve bodies are Nuova Simonelli adapted and feature a LM anti-vac valve on each wand.
Custom paddle switch – functionally the same as Marzocco MP group, two stage operation, but electrical rather than mechanical so there are no seals to change.
Chronos key pads for shot clock, volumetrics on both groups with a manually controllable preinfusion function. Use either touchpad or manual paddle at any time. I find I like to flush with the paddle and pour shots via the touchpad.
Custom made dispersion block in POM-C (same as current Speedster setup) for cleaning ease, temp stability.

SOLD – Conti Prestina

Posted on November 23rd, 2014

Conti Prestina

single group lever machine

For sale is my Conti Prestina single group lever machine, fully restored. These machines are very rare in Australia and is the only one I have ever seen. The Conti group is unique, using a series of linkages to convert the lever action to a vertical piston movement. This machine has an incredibly small footprint for it’s capability and boiler volume, Conti used an innovative compact construction to place all the necessary components on the massive boiler flange.

This machine has been rebuilt from the ground up with OEM parts sourced directly from Conti in Monaco, who still make spares for the group. Replaced parts include the group spring, pressurestat, wiring, silicone boiler insulation, nuts and bolts where mild steel was used, and all gaskets and seals.

Operationally the machine is in perfect condition, and cosmetic condition is excellent. There are a few spots where the protective lacquer is lifting off the brass plated panels, and a few minor blemishes in the front panel and base.

This is a 10 amp (standard household power) machine and requires a plumbed mains water supply or flo-jet pump.

Price: $2,900 including GST.

Andy’s Londinium

Posted on August 9th, 2013

Andy’s Londinium

Domestic lever dual boiler conversion

The Londinium Espresso L1 is a new addition to the market for single group lever machines intended for domestic use. There has been a recent resurgence of interest in lever espresso machines, as we are finding out more about the subject of ‘pressure profiling’, or controlling the water pressure applied to the coffee puck at different stages of the extraction.

Andy was a little disappointed with both the fit and finish and the temperature stability of the machine, so we decided to see what we could do to take it to the next level. Without going into too much detail, the Londinium uses a fairly uncommon thermosyphon arrangement to get enough heat into the massive group. After gathering some data on how the thermosyphon functions and comparing this with other user’s data from around the world, it appears that there are conditions that can alter it’s performance, resulting in low group temperatures and sour shots.

We considered a few options, one of which was reconfiguring the thermosyphon into a true heat exchanger that operated from mains water pressure instead of the built-in tank, but Andy was keen to retain the ability to run from tank. This meant a drastic alteration of how the group was heated, and the fabrication of a separate brewing boiler to tightly control the water temperature at the group. Luckily, the internal construction meant that the original boiler could be retained and minimal alterations to the layout were required.

The end result is a traditional lever machine that has all the inherent temperature controls of a modern dual boiler machine. Changing the set temperature of the brew boiler controller results in a quick change in the idle temperature of the group itself, which governs the temperature profile of the shot.

We were also able to address a few of the annoyances with machine fit and finish, such as ease of emptying the drip tray, placement of switches and internal venting of the anti-vacuum valve.

Andy is stoked, and the proud owner of what may be the most technically advanced lever machine in the world.

Restoration projects

Posted on September 21st, 2012

Restoration projects

creating functional classics

It could be argued that espresso machine design reached it’s peak in the workshops and foundries of northern Italy in the mid 20th century, and everything since then has been a bit boring! There’s a certain character about machines of that era that just exude flair, passion and artistry. And while not many of us are lucky enough to own a Gaggia Esportazione, Cimbali GranLuce, La Pavoni Concorso, La San Marco Lollobrigida or Faema Urania, it’s certainly true that any vintage coffee machine is eminently restorable to perfect working condition given enough love and attention.
Whether you’ve got an older second hand machine that you want to bring up to scratch for domestic or cafe use, or you’ve uncovered a gem in a forgotten corner of the garage, I can help you with either a complete restoration from start to finish, or a particular aspect if you’re doing most of the work yourself. My aim with restorations is always function before aesthetics – what’s the point having a shiny beautiful machine if it makes rubbish coffee or no coffee at all. After that, anything is possible including installing modern electrical systems, re-plating or re-manufacturing worn parts, re-spraying paintwork and reproducing original factory artwork. My preference and advice is always to preserve original finishes where possible, as this preserves character and adds value to the machine in the long term.

Naturally these hands-on processes can be very time consuming, and I assess and quote each restoration project as a flat labour fee plus expenses, according to the result you want to achieve.

Repairs and servicing

Posted on September 21st, 2012

Repairs and servicing

Keeping you extracting – commercial or domestic

Repairs and servicing are what I spend most of my waking hours on. When things aren’t working as they should, you need the problem rectified quickly so you can keep enjoying your equipment. With many years of experience working on all brands of commercial and domestic espresso equipment, I’ll ensure that you’re back up and running with the minimum of fuss – whether it’s as simple as changing a filter or adjusting pump pressure, right through to a major breakdown.

You’ll also get the kind of personal service and attention to detail that you can only expect from a dedicated individual. I want you to be happy with my work, and I’ll take the time to make sure that you are. Crucial to that is that I don’t just know machines, I know coffee and I can have a conversation with you about how different parameters in the machine affect the results, and look at your whole system including the machine, grinder, coffee and water source to identify issues that may not have been readily apparent.

For domestic equipment, if you are dropping off at my Northcote workshop location I aim for a 48 hr turnaround. Otherwise, an on-site call may be required if the equipment is hard to move, or in commercial use. See the FAQ page for more details.

For commercial clients, if it’s not a breakdown I’ll work with you to attend at a time that suits your business. The last thing you want is to be turning customers away because your machine’s out of action.

Improvements and modifications

Posted on September 21st, 2012

Improvements and modifications

Getting the best from your gear

While most domestic and commercial espresso equipment on the market is capable of achieving excellent results, there are occasions where better performance can be gained from making a few simple internal modifications. Through monitoring how the machine is behaving, we’d be able to assess what, if anything, could be gained in terms of temperature stability at the group or other usability improvements eg. better steam pressure, quicker recovery time etc. If you’ve got something in mind, I can tell you whether it’s going to A. give you the result you want, and B. remain safe and cost effective.

Thermosyphon Restrictors

In most cases, excessive group temperatures in traditional heat-exchanger machines can be controlled through the addition of a thermosyphon restrictor (a small disc with a precisely sized opening, placed into the heat exchanger) that is tuned to the particular temperature that you want to achieve. This allows you to lower the temperature at the group without losing steam pressure, and negating the need for a cooling flush. It’s a very simple but significant upgrade for most domestic E61-group machines that run hot – associated with burnt or bitter flavours in espresso and steam/spluttering from the group when the pump is activated.

Temperature studies, PID control and boiler upgrades

For the ultimate temperature control, some machines may benefit from replacing stock thermostats or pressurestats with modern PID hardware. This often has a dual benefit in terms of easy temperature adjustability, and long term reliability as digital controllers and associated devices have no moving parts.

Usability improvements

The list of possibilities are almost endless. If you’d like to improve your existing machine rather than upgrading, give me a call and we’ll see what can be done. Some suggestions to get you thinking:

Swapping steam and hot water wand locations
Upgrade to lever-activated steam valve or cool-touch wands
Custom steam tips for more usable steaming
Two-stage pre-infusion switch for semi-automatic solenoid groups
Upgraded heating element control system incorporating solid state relays for greater reliability
Adding auto-fill controllers to older manual fill machines
Plumb-in conversions for tank machines