dcbrown1 wrote:Hi, I have a GS3 and I find the idea of a flow valve intriguing. That said, if you were doing it all over again...would you do it all over again. Interested to know if the juice is worth the squeeze! I've had pretty good luck striking the right balance between time and quantity by tweaking the grind. Thoughts? Cheers, Dave

Dave,

Thanks for chiming in. I had a commercial HX machine for the last 6 years or so that I modified for flow profiling about a year ago before I received my GS/3. I made very good espresso on the GS/3 in stock form, but it was immediately apparent to me that I made consistently better espresso with my profiling HX machine.

Everything Peter said is spot on. If I had to sum up the compelling reason to have a profiling machine in one paragraph (or 17 ), it would be this particular post from Jim's Bianca review:

The Bianca for Espresso Newbies and Intermediates

If you're at all interested in the "why do any of this?" Side of things, feel free to check out the ramble, which documents my entire journey into profiling espresso machines in gory detail.

The GS/3 is quite a forgiving machine in stock form. It has a gentle flow rate and excels at pulling consistent shots and steaming effortlessly. What I've found is that although the stock shots are very consistent, they also consistently leave a little bit on the table as far as performance in the cup goes. Are the shots very good? Absolutely. Even so, I have yet to find a bean that doesn't benefit from some sort of profiled shot. Be that a declining profile to minimize the bitterness in the tail end of a shot, or preinfusion at 2-3 bar to soften the puck and enjoy a more extracted ristretto with a tight grind, or both. Back to back shots are almost always more enjoyable to my palate when exploring the wider extraction space provided by profiling.

Cheers!

- Jake

Jake...
I am intrigued about the ease of your mod. I have a GS/3 AV that sits under low cabinets, so you mod is perfect since it does not increase the height of the machine. I will need to modify the firmware to exceed the 50 second limit the GS/3 AV has for pulling a shot. Could I get a link to the modified firmware and what I would need to flash the machine ? Also, the file for the 3d printed custom knob and bracket you created which I would send to an online 3d printer site to manufacture it for me.

thanks..

Loren

In the meantime you'd probably be pretty pleased with the new capability even without the firmware timer extension. AND you can still use the machine as if totally stock. So you don't have to commit to an un reversible situation. All win, IMHO.

-Peter

Jake, interested to see how phase 2 of this is coming along...this looks pretty sweet.

Loren,

Please keep us posted on your progress with the mod when the fittings come off back order. Did you flash the firmware yet?

Peter,

Absolutely 100% correct. Though I do wonder what lurks beyond 45s...

Jason,

V2 has been on the back burner for a bit for a couple reasons.
First, V1 is really nice to use and I like the results quite a bit as is.
Second, V3 may very well find it's way to fruition first, leaving V2 in the dust... I'll keep you posted, but don't hold your breath. I'm notoriously cautious and slow when it comes to developing stuff.

Cheers!

- Jake

There's a V3? What does that entail , or is there another thread I missed.

Perhaps V3 has wires. A red one, a black one, an orange one and a yellow one.

Perchance?

Mulling over Jacob's build I am starting to think he never tapped into the flow meters. That part was overkill on my side. That is why his RPM is relatively consistent.

Considering that the FG has a tachometer output that is tied in to the Hall Effect sensor, you have all the making of a pretty good volumetric pump. My guess is that it isn't going to be as simple as ml/sec = pulses/sec x vol/pulse due to slip. But more likely pulses/sec * vol/pulse * correction where the correction will depend on the drive (orange) voltage. A calibration lookup table with interpolation may be easier.

It is quite a pump.

Wait,

The tach output is tied to gear speed, not motor speed?