Hi all,
Im new here.
I have been a barista for a few years but have a background in electronics & fiber optics. I also like to tinker....

I have bought both of Todd's 2 group Lineas & will be doing the rest of the rebuild, as well as a few mods. Here is the link to his thread La Marzocco Find...What have I gotten into!

So Im going to rebuild them one at a time. While Im at it, I figure I might as well do a few mods.
I'll be doing the PID upgrade first.
Im thinking I will also insulate the boilers as well for greater thermal efficiency. Anyone know if this will cause problems with the PID unit?

Im thinking that since the machines dont have pumps, I might as well get myself a TMFR pump & controller & be done with it. Any ideas how much these cost?

Any ideas how much these cost?

The TMFR Pump/Motor and Drive are about $300. But to that you need to add in:

Properly configured Fuji PXG4 Controller ~ 269
Pressure Transducer ~ 155
Regulated Power Supply ~ 44
Project Box ~ ?
Miscellaneous Wire, Terminal Strips, Connectors ~ ?
Blood, Sweat, Tears ~ ?

It "ain't" inexpensive BUT see this for a somewhat less expensive but still very effective and neat manual control setup:

'Pressure Profiling' With The Fluid-O-Tech TMFR Pump - Or, Wholesale Copying Greg Scace's Ideas

Hi Erics, Thanks for your reply.
This will be a test subject for me, if it goes well, Ill implement the changes in the FB/70 3 group at work.
I want the repeatable aspect for a busy cafe.
Also I eventually want to do a 4 group Linea with separate temps & profiles on each brew boiler, for a guest SO espresso as well as the staple Blackcat.

I would love a pair of Chronos keypads, not a fan of the AV keypads. Prefer manual controls but I like the integrated timer.
Want to put in some barista lights & maybe a reflective strip a la the Slayer machine.
I hate the standard steam knobs, thinking of making an Synesso style side lever.

Thinking of using pressure & temp sensors very close to the groupheads & using the internal flowmeter (I suspect it just sends pulses, but not sure).
For now Im thinking of using a few programmable analog input units to record & display data (temp, pressure & flow rate) on my netbook.
I can also use a programmable analog output unit to feed S-curves with adjustable curves & trapezoidal ramps with programmable ramp rates to the input of the pump motor controller. Then its a scace II device to calibrate my system.
I would also like to use an output from the brew PID module so that I can compensate for any small margin of error from brew boiler temp to head temp.
Once thats done & working well, Ill do a microprocessor with enough memory to save a few hundred profiles, a dot matrix display & a serial interface for tuning & dumping data

Can anyone tell me what the output signal of the Lineas flow meter is?

Is it a pulse or varying voltage?

Why use a tmfr pump instead of a gear pump?

Pls enlighten me on gear pumps

Will I still have the same degree of control over the pressure, as I want to do exponential pressure curves & linear ramping, etc

Pls enlighten me on gear pumps

See page 3 of the link I originally provided. Sometimes, it helps to use this site's search engine

If it were me (and it's obviously not) rebuilding two Lineas, I would CONSIDER making a rather insignificant investment in a 220-240vac vibe pump to prove out the machine's fully before engaging into a substantial investment in pump's and controls.

Rosscopico0 wrote:Pls enlighten me on gear pumps

Will I still have the same degree of control over the pressure, as I want to do exponential pressure curves & linear ramping, etc

They are what LM are using in the Strada for that pressure control, plus by counting revolutions of the motor you have a pretty good flowmeter. Its a better solution for sure, at a third the cost.

Hmmmmmm, very interesting!!

Sometimes, it helps to use this site's search engine

Silly me, I used google!

So to check Ive got this right, the flow rate & the pressure vary proportionally to the input voltage?

If you insulate, only insulate the steam boiler. Since you will be adding Temp controls (PID), you will need the heat loss from the boiler to get the temp controller to function properly. A little insulation is OK but not greater than about 1/8 inch.

For the gear pump, these things are great. Essentially it depends upon what kind of motor you are using, but with a brushed DC motor you can either vary the voltage or send a PWM signal to it to control the speed of the motor. The speed controls the flow rate. Since pressure is directly dependent upon flow rate it also controls pressure. Another cool thing about gear pumps is that they are pretty accurate (as good or better than a flow meter). This means that you can also use the gear pump as a flow meter.

If you are using this on a 2 group you will only be able to use one group at a time.


bill