# Pressure gauge on Robot (Barista vs Regular) and other lever machines



## BobbyAxelrod (Jan 12, 2021)

Hi,

I recently read the following recommendation on the UK cafelat blog (https://www.cafelat.co.uk/blogs/cafelat-robot-manual/barista-vs-regular)



> We always recommend Regular Robot for home-user, but it's completely your choice. The Barista Robot with the gauge system is also a bit more involved whereas the Regular Robot is bullet proof.


 I was really expecting the pressure gauge to be essential to reduce variance in shot quality. However, this page claims



> After a dozen or so uses you will get a feeling of how much force they need to exact and not read the gauge anymore.


 I am curious to hear about people experiences on this topic.

Is it really possible to consistently pull great shots without a gauge?

How fast could you learn that skill from scratch without a gauge?

And finally, does that depend on the lever machine used? Is the Robot particularly "forgiving"?

Cheers,

Bobby


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## newdent (Feb 20, 2021)

BobbyAxelrod said:


> Hi,
> 
> I recently read the following recommendation on the UK cafelat blog (https://www.cafelat.co.uk/blogs/cafelat-robot-manual/barista-vs-regular)
> 
> ...


 I get the vibe that Paul's original vision with the robot was simplicity, no pre-heat, no gauges, etc, hence his biased recommendation - the cost is also kept down. There's no doubt that if you're pulling more traditional roasts and you're not chasing clarity of flavours from lighter roasts, you can pull shots by feel but what's the point or risking a bad coffee? I can guess the speed I'm going in my car but if there's a speed camera coming up I'm going to glance at the gauge, I really don't see why you wouldn't want to use the gauge...

As a robot owner who strives for consistency in my shots, I would say get the gauge. In the lower pressure ranges, it's quite easy to generate pressure and your pre-infusions could be all over the place. The difference in force applied and 1 bar vs 3 bar of pressure is negligible but it makes a huge difference on how long it takes the basket to saturate, like double the amount of time.

I'd say that flow rate is the parameter to chase once the shot is underway and that can only be done by eye and ears in absence of a fancy scale (none of them fit under the robot anyway, possibly the small acaia goes diagonally) so the gauge becomes less important but for how much extra it costs to add the gauge, no question go for it.


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## 2971 (May 7, 2012)

I have the Robot with the gauge, and would be very happy without the gauge. After a few shots, you pretty much know how hard you have to push to get 9 bars. The gauge is not very elegant, and I dislike the snaking tube that runs into the body of the Robot.

I may not be the most sophisticated drinker, but the Robot seems to pull tasty shots far more than any other machine I've had (which includes the Cremina for example), and it's much harder to muck things up. I reckon if I'd bought without the gauge, my coffee would have been fine, but I'd forever be wondering if I was pushing with the right pressure.


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## newdent (Feb 20, 2021)

Just to add to this, the pressure I use is the most pressure I can apply without any visible surges on the underside of the basket. Generally, I've found that for the first 1/3 to 1/2 of the shot, the puck can tolerate much higher pressures but as the puck erodes, you need to come down to 4 or 5 bar to prevent surges.

What the gauge is handy for is consistent pre-infusion pressure and peak pressure. I think these are the pressures that are important to keep consistent. I hear the original mounting position of the gauge isn't ideal but it's easily changed with a custom bracket similar to the naked portafilter mod:










I don't see why the robot would be any more forgiving than any other manual lever, there's certainly no logical reason I can think of. A manual lever in general is more forgiving than a pumped machine for sure. Being able to feel the puck pressure and immediately adjust pressure is incredibly useful, whereas even a flow controlled machine like the bianca, you'd have to wait until there are visual cues before adjusting the flow.


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## BobbyAxelrod (Jan 12, 2021)

newdent said:


> I get the vibe that Paul's original vision with the robot was simplicity, no pre-heat, no gauges, etc, hence his biased recommendation - the cost is also kept down. There's no doubt that if you're pulling more traditional roasts and you're not chasing clarity of flavours from lighter roasts, you can pull shots by feel but what's the point or risking a bad coffee? I can guess the speed I'm going in my car but if there's a speed camera coming up I'm going to glance at the gauge, I really don't see why you wouldn't want to use the gauge...
> 
> As a robot owner who strives for consistency in my shots, I would say get the gauge. In the lower pressure ranges, it's quite easy to generate pressure and your pre-infusions could be all over the place. The difference in force applied and 1 bar vs 3 bar of pressure is negligible but it makes a huge difference on how long it takes the basket to saturate, like double the amount of time.
> 
> I'd say that flow rate is the parameter to chase once the shot is underway and that can only be done by eye and ears in absence of a fancy scale (none of them fit under the robot anyway, possibly the small acaia goes diagonally) so the gauge becomes less important but for how much extra it costs to add the gauge, no question go for it.


 Thanks @newdent 

I was also guessing the gauge would help speed up trial and error, by making it easier to more or less fix the pressure profile if you play with another variable (e.g. grind setting). And I'd expect gauge feedback to be more accurate than muscular feedback ????

I did not realize pre-infusion could bring that much variability in the shots, and how the gauge could help for that. That's super interesting!

Also I did not know that monitoring the flow rate was a good strategy, thanks for sharing that!



wintoid said:


> I have the Robot with the gauge, and would be very happy without the gauge. After a few shots, you pretty much know how hard you have to push to get 9 bars. The gauge is not very elegant, and I dislike the snaking tube that runs into the body of the Robot.
> 
> I may not be the most sophisticated drinker, but the Robot seems to pull tasty shots far more than any other machine I've had (which includes the Cremina for example), and it's much harder to muck things up. I reckon if I'd bought without the gauge, my coffee would have been fine, but I'd forever be wondering if I was pushing with the right pressure.


 Thanks @wintoid  I'm not the most sophisticated drinker either, but also definitely not the most skilled barista ???? So the gauge might still help me taking out a lot of the guessing game and wasting less coffee.

Aesthetically speaking, the gauge has indeed a bit of "patch" vibe as it was not in the original design.



newdent said:


> Just to add to this, the pressure I use is the most pressure I can apply without any visible surges on the underside of the basket. Generally, I've found that for the first 1/3 to 1/2 of the shot, the puck can tolerate much higher pressures but as the puck erodes, you need to come down to 4 or 5 bar to prevent surges.
> 
> What the gauge is handy for is consistent pre-infusion pressure and peak pressure. I think these are the pressures that are important to keep consistent. I hear the original mounting position of the gauge isn't ideal but it's easily changed with a custom bracket similar to the naked portafilter mod:
> 
> ...


 That puck erosion -> lower required pressure makes sense 

The dynamic adjustment thanks to pressure feedback is really cool, especially if you "save a shot", that must be so satisfying ????

Quick question about that mod - it seems you can't watch both the extraction (I mean the portafilter from under) and the gauge from the same position. Wouldn't it be better to be able to have both in sight?


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## 2971 (May 7, 2012)

newdent said:


> I don't see why the robot would be any more forgiving than any other manual lever, there's certainly no logical reason I can think of. A manual lever in general is more forgiving than a pumped machine for sure. Being able to feel the puck pressure and immediately adjust pressure is incredibly useful, whereas even a flow controlled machine like the bianca, you'd have to wait until there are visual cues before adjusting the flow.


 There could be lots of reasons. For example, the Ponte Vecchio I had was a 51mm basket (I think), and the Caravel and Cremina were 49mm (again, from memory). Perhaps it was basket size?

That said, the Caravel could make a faultless ristretto, time after time, just not a longer shot.


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## newdent (Feb 20, 2021)

wintoid said:


> There could be lots of reasons. For example, the Ponte Vecchio I had was a 51mm basket (I think), and the Caravel and Cremina were 49mm (again, from memory). Perhaps it was basket size?
> 
> That said, the Caravel could make a faultless ristretto, time after time, just not a longer shot.


 I've heard of deeper baskets being more forgiving due to less chance of channelling but them lacking clarity.

The 58mm pucks are thinner and make clarity easier to obtain but better puck prep required due to it being thinner and more fragile.

The former is just from what I've read as I've only ever had 58mm machines but seems to tie in with what you said.


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## newdent (Feb 20, 2021)

BobbyAxelrod said:


> Quick question about that mod - it seems you can't watch both the extraction (I mean the portafilter from under) and the gauge from the same position. Wouldn't it be better to be able to have both in sight?


 Yes, better to have both in sight. My retro-fitted gauge is in a similar position to the picture I added (but not as high) and I use a shot mirror to the right of it for visiting the backer, then my scales are on diagonally with the display to the lefty of the gauge. Then I can see the weight, pressure and basket with just a quick movement of the eyes.

The gauge looks even worse positioned there but it's actually fine as I store the robot with the gauge side against the wall so the aesthetic isn't ruined too much.


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## BobbyAxelrod (Jan 12, 2021)

newdent said:


> Yes, better to have both in sight. My retro-fitted gauge is in a similar position to the picture I added (but not as high) and I use a shot mirror to the right of it for visiting the backer, then my scales are on diagonally with the display to the lefty of the gauge. Then I can see the weight, pressure and basket with just a quick movement of the eyes.
> 
> The gauge looks even worse positioned there but it's actually fine as I store the robot with the gauge side against the wall so the aesthetic isn't ruined too much.


 Ahh using the shot mirror a good trick! Thanks!


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