Cafelat Robot User Experience - Page 194

A haven dedicated to manual espresso machine aficionados.
jpender

#1931: Post by jpender »

superdudeo wrote:What is the going consensus on tamp pressure with the robot? I think in the manual it says only a gentle tamp is required?

I think the most recent consensus (regardless of the machine) is that tamping pressure doesn't really matter as long as you at least tamp a little. After that you aren't going to make much of a difference. Coffee grinds are really, really hard to squash. Once you reorient them a bit with a tamper that's about all you're going to get. So you might as well save your wrist/shoulder/hand the trouble and just give a light tamp.

Nate42

#1932: Post by Nate42 »

cooperpwc wrote:Here is an interesting article. It provides some support for the excellent results we get from the Robot at lower pressures:

https://www.smh.com.au/national/interna ... JA_qfIgkRg
Remember, our "low pressures" on the Robot aren't actually that low, because of the measurement point. The robot pressure port is right in the cylindar, so it should be a very accurate representation of the pressure at the puck. In most other machines the pressure meter taps off somewhere before the group, which often includes some kind of flow restricter that will produce back pressure. The gicleur in an E61 for example.

At the puck, our 6bar probably isn't that far off from 9 bar on an E61 machine. Someone smarter than me has probably already done the math. :)

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Spitz.me

#1933: Post by Spitz.me »

Paul_Pratt wrote:I m a big believer in getting stuck in and finding things out for yourself.

Not directed at you, just a general comment - I would not say it is a mistake for people to read as much as they can when they are getting into coffee, but it is important to experiment and learn and be prepared to waste a bit of time and coffee and have an open mind. Hopefully the reading will shorten the learning curve.
+1

You can read all you want, but you always find out how much less you actually understand when you start practicing. Sometimes it seems as though we're trying to manage to not take life threatening risks with things that are effectively meaningless and with a maximum risk of "it tastes bad" and coffee waste (as if this is NEVER going to happen).

For instance, do we really need to ask, "Can I try this coffee as espresso?" Why not just see if it works? Maybe you're actually wondering, "How can I pull this X type of coffee designed for filter to get a passable espresso?" There just generally seems to be a fear of insignificant failures that can only lead to learning - at all times.
LMWDP #670

vit

#1934: Post by vit »

Nate42 wrote:Remember, our "low pressures" on the Robot aren't actually that low, because of the measurement point. The robot pressure port is right in the cylindar, so it should be a very accurate representation of the pressure at the puck. In most other machines the pressure meter taps off somewhere before the group, which often includes some kind of flow restricter that will produce back pressure. The gicleur in an E61 for example.

At the puck, our 6bar probably isn't that far off from 9 bar on an E61 machine. Someone smarter than me has probably already done the math. :)
Pressure difference through the restrictor is proportional to the square of the flow. So you measure your water debit and flow when making coffee and if pump pressure is known, it's easy to calculate.

Let's say water debit is 250 ml/30s and flow when making the coffee is 50ml/30s (1/5 of water debit). You know that pressure difference without PF is equal to the pump pressure, so if it is 9bar, then pressure difference on restrictor when making the coffee is 1/25 of that or 0.36bar when the flow stabilizes. At the beginning, flow is considerably higher, so is the pressure difference, so there will be a smooth pressure ramp up

So pressure drop on restrictor is not that high actually ...
★ Helpful

Nate42

#1935: Post by Nate42 » replying to vit »

Huh, I would have thought it would make more difference. I'm an electrical guy though, fluids hurt my brain.

Dogshot

#1936: Post by Dogshot »

Absolutely loving my Robot. It is probably the best espresso machine I have ever owned (which includes an Elektra Semiautomatica, Ponte Vecchio Export, and Expobar Brewtus II). I have purchased a Bellman stovetop steamer for my wife's morning cappuccino, and together with my Vario, the combination is unbeatable in terms of value for cost.

My wife made coffee yesterday, and when I got home I found this:


Do any locations in the US carry shower screens for the Robot, or am I going to have to order directly from Cafelat? The only problem with ordering direct is that I have no idea how much import fees will be to Canada, and more importantly the shipping can take anywhere between 10 - 60 days. I'd rather not wait 2 months for the part.
LMWDP #106

baristainzmking
Supporter ♡

#1937: Post by baristainzmking »

I would check with Prima Coffee, as they now carry the Robot.
Julia

Dogshot

#1938: Post by Dogshot » replying to baristainzmking »

Thanks - the part is not listed on their website, so I have sent them an email to find out for certain whether they carry the screen.
LMWDP #106

notarealbarista

#1939: Post by notarealbarista »

Dogshot wrote: My wife made coffee yesterday, and when I got home I found this:
image
Just out of curiosity..how was she able to achieve that? seems like she would have had to apply quite a lot of force but how does this bend like it did?

MNate
Supporter ♡

#1940: Post by MNate »

Dogshot wrote:Absolutely loving my Robot. It is probably the best espresso machine I have ever owned (which includes an Elektra Semiautomatica, Ponte Vecchio Export, and Expobar Brewtus II). I have purchased a Bellman stovetop steamer for my wife's morning cappuccino, and together with my Vario, the combination is unbeatable in terms of value for cost.

My wife made coffee yesterday, and when I got home I found this:
image

Do any locations in the US carry shower screens for the Robot, or am I going to have to order directly from Cafelat? The only problem with ordering direct is that I have no idea how much import fees will be to Canada, and more importantly the shipping can take anywhere between 10 - 60 days. I'd rather not wait 2 months for the part.

I bet Paul would tell you to bend it back and it will work fine. He seems fairly laid back about that aspect.

On the tamping pressure discussion...
I have wondered even about not bringing the tamper for my airplane travel setup. It just might not make that much difference to press down with the screen. I'll try a bit. I've also though of leaving the scale behind. Which is more detrimental:
A) not knowing how much coffee you're using, or
B) not having a great (any) tamp?