# What elements are needed to make the perfect home machine?



## angio (Jul 10, 2015)

I need your help!

I've been tinkering with a knackered gaggia classic and I've come to the conclusion that I could potentially make my own ideal coffee machine. I have a lot of the tools I'd need to fabricate parts but what I need to understand is what makes the difference between say the Gaggia Classic and a commercial grade unit costing thousands of pounds so I can add them to the design.

I'm not even sure this project will get off the ground and if it does it will be a long term project but if it works out I could end up with something quite special and unique!

What features are present in a commercial machine that makes them superior to a home machine?


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## Dylan (Dec 5, 2011)

Things to look up, in no particular order of importance.

Heat Exchanger type

Double boiler type

Pre-infusion/ pressure control, and pre-infusion control (Vesuvius/ Rossa PG)

Accurate brew temperature control (PID)

E61 group head design history

Obviously is depends on your level of expertise and dedication, but I would say its a pretty mammoth project to be considering.

Have a look for the ZR-71 grinder project on here, a now virtually complete custom built grinder by one of the members on here with features that read like a dream list for a grinder (if you dream about grinders)

Building a machine has been mused about a few times before, never seen it done. It may be a good idea to buy a broken machine for cheap on ebay and repair it, that would give you a really good idea of the internal workings.


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## The Systemic Kid (Nov 23, 2012)

God loves a tryer

Commercial machines introduced volumetrics - delivering set amount of water through the puck. Latest development is gravimetrics - delivering shots to pre-determined weight output. Then there's variable pressure profiling but this is available on some high end domestic machines.


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## Dallah (Jan 31, 2015)

Volumetrics available on the Sage and La Spaz. As far as I am concerned on a morning when I am cranking out milky espresso drinks for 4 people in 15 minutes, the volumetrics are a god send.

If you are serious I would suggest that you get an account with LF as they have components for lots of machines. You could assemble your dream machine from the parts with the body work being the custom part.


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## angio (Jul 10, 2015)

It certainly is a mammoth project, I'm certainly not entering into this with the expectation that thiswill be quick or easy. I do however know my way around the inside of a domestic machine sufficiently will that I could put together a pastiche of a gaggia classic.

I'm not sure my abilities would stretch to a gravimetric dispensing system and to be honest I personally prefer manual systems anyway.


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## DavecUK (Aug 6, 2013)

Always love these build a machine yourself threads. It can be done (rarely), but usually people don't realise what they are taking on....good luck with the project.


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## Jumbo Ratty (Jan 12, 2015)

I doubt this is ideal, but may give you some idea of what others have achieved.

I like the look of the boiler but the portafilter is a bit dubious.

http://gadgetshow.channel5.com/gadget/episode-2-coffee-machine-build


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## jeebsy (May 5, 2013)

Giant boilers


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## Cana (Mar 7, 2015)

angio said:


> I need your help!
> 
> I've been tinkering with a knackered gaggia classic and I've come to the conclusion that I could potentially make my own ideal coffee machine. I have a lot of the tools I'd need to fabricate parts but what I need to understand is what makes the difference between say the Gaggia Classic and a commercial grade unit costing thousands of pounds so I can add them to the design.
> 
> ...


http://conversation.ceramichelea.com/2012/08/seppl-ceramic-espresso/#more-3812

Have a look at this for design and simplicity. Very stylish espresso machine.


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## Cana (Mar 7, 2015)

Jumbo Ratty said:


> I doubt this is ideal, but may give you some idea of what others have achieved.
> 
> I like the look of the boiler but the portafilter is a bit dubious.
> 
> http://gadgetshow.channel5.com/gadget/episode-2-coffee-machine-build


Oh love that boiler.. Even if you would have to manually release pressure... They didn't seem to include an antivac valve though.


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## angio (Jul 10, 2015)

Jumbo Ratty said:


> I doubt this is ideal, but may give you some idea of what others have achieved.
> 
> I like the look of the boiler but the portafilter is a bit dubious.
> 
> http://gadgetshow.channel5.com/gadget/episode-2-coffee-machine-build


Stick a couple of wheels on it and set up a track and you could have it chugging around your house or an office dispensing shots of steam propelled joy!


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## angio (Jul 10, 2015)

So this is still in it's infancy but in the interests of bringing it along I decided to use a preexisting machine as the basis for the project. So I picked up this for £50:









I had hoped that it was the Rancilio Tecna but its the next model up with the 11 litre boiler and 3 phase heating element. The heater is wired up to run off single phase but the amperage means I'll need to hard wire it into the wall. I can temporarily spur it off the cooker feed but if i keep this boiler/heater combination I'll wire up it up to the consumer unit with it's own rcd. I think the boiler is a bit big but this machine gives me the volumetric control plus a solid foundation for my dream machine.

I also quite like the idea of gravimetric dispensing - I have considered integrating an android tablet or raspberry Pi so connecting up a balance with two way communication is a very real possibility.

Onwards to the drawingboard.


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## Brewer in training (Feb 7, 2015)

Didn't realise you were after a donor machine..... Had a Gaggia TD 2 group 5l machine that was a 13amp...... Would have been a good starting point.....

Mind you, it did have a few missing bits n bobs.......

Looking forward to how this pans out...... Good luck in your endeavours...


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## angio (Jul 10, 2015)

Honestly, I didn't think I was going to go down that route but that Rancilio came up and it was too good a price to pass up.


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## jeebsy (May 5, 2013)

11 litre boiler...wow. This should be interesting!


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## Gander24 (Apr 11, 2015)

Good luck!!!!


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## angio (Jul 10, 2015)

Just a brief update; the Rancilio was just too big as a donor and I now have an Iberital L'Anna Handy with a borked gicar controller as the base of the project.

With regards to the controller, I'm swinging towards an arduino rather than raspberry pi as they are more capable of handling the complexity of the suite of sensors and relays I am looking at running in the machine. That and I've always wanted to learn C++!


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## angio (Jul 10, 2015)

A bit of an update:

Not only was the Gicar controller not working - looks like water damage but the relay for the heater element was shot and the heating element only had two function loops out of the three.

I figured that to do this properly I needed to start from absolute zero and work my way incrementally up to the "dream machine". This is one big learning exercise for me and although I can open up coffee machine and diagnose what isn't working (most of the time) I may not fully understand what all of the components do - especially the electronic widgets. This was made clear to me when I received the new heating element and I couldn't for the life of me work out why it wasn't heating even though there was power running through it - the LED was lit after all. Turns out that there is a high ohm resistor in the LED ( the resistor protects the LED from the high current of mains electricity) that I had wired in series in the test circuit for the new element and that resistor was choking the current going into the element. I rewired the circuit with the LED in parallel with the element and lo and behold I had heat.

This way of doing it prolongs the project but it does mean I will know the L'anna inside and out.

So, in it's current incarnation, the L'anna makes coffee and is effectively one big Gaggia Classic - everything is controlled electromechanically with none of the electronic control that it came with.









It is now sporting a rather ugly (and very temporary) clip lock tupperware box with a switch for choosing between the solenoids and another for activating the selected solenoid and the pump. It's crude but it means I can use the L'anna to make coffee rather than it sitting sadly in the corner.

The lack of electronics means that unfortunately the level sensor for the boiler doesn't currently work but the chaps at Iberital rather helpfully added a drain valve to the bottom of the boiler. When the boiler is cold I can pop on a clear silicone hose, hold it upright and open the valve the water level in the hose corresponds with the water level in the boiler much like a sight glass you find on a lot of other coffee machines. This obviously only works when the boiler is cold and requires the side panel to be removed. Mind you it's better than accidentally running the boiler under-filled and breaking the element.

The next step is integrating the arduino into the L'anna and regaining all of the lost functionality such as level sensing, automatic boiler filling and volumetric control. I've already figured out the pins in the dispense panel - it's effectively five momentary switches and five LEDs behind the membrane screen so that will be reinstalled as part of the next phase.

I have fiddled with the arduino a steel milk jug of water and I'm pretty certain I can incorporate the conductive level sensing system to control the boiler water level:









I also have the two relays on a board that the arduino can control to activate the boiler fill solenoid and the group head solenoid so I now have everything I need to get the L'anna back to factory functionality.









Now all I need to do is write some code and make some circuits up and the tupperware box can go in the bin! Once this phase is complete I'll have a coffee machine with E61 group head, volumetrically controlled system, automatic boiler fill and water reservoir level sensing and alarms.

Future plans:

PID control. I have a solid state relay that the arduino board can control on it's way to me as I type.

touch screen interface (probably show realtime temp and pressure - not given this much thought yet).

gravimetric control: pressure sensor either under the cup or in the main body of the machine. Again not given this much thought yet either.

wifi/bluetooth control - probably the last thing I'll try to add; I'm still learning to programme the arduino so I'll save android app development for another day.

If there's anything else I you think I should add or consider then let me know!

More to follow soon.


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## Brewer in training (Feb 7, 2015)

Looking good.... Liking the the idea of a touch screen display..... Might have to ask endless questions so I can openly plagiarise the idea..... (Who am I kidding? Couldn't learn to program it...)


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