Thanks for the tips, I'll try right away with dosing down to 14g!

Regarding pressure after pre-infusion I ramp up during 3 seconds roughly.

3 seconds seems fast to me.

TomC wrote:...or change your coffee.

I'd give that a try before pulling all of your hair out.

Sometimes a particular coffee is really difficult to get to work. Sometimes nothing seems to work. Whereas other coffees are so forgiving that every shot is good without even having to try.

Dosed down to 14 and then 12 grams now. Managed to pull two enjoyable shots so now I am on the right path! Ratio roughly 1:3, 10sec pre and a total of 50 sec. Thanks!

ojaw wrote:3 seconds seems fast to me.

What would you recommend? And how does the ramp up time affect the result?

Glad it's starting to work out for you, @Mister Fox. FWIW, I usually ramp up in 3-5 seconds.


Today I took the base off of my Robot as I wanted to polish it. As I am also toying with the idea of adding a short extension to the struts I measured the bolts, base plate thickness, and how far the bolts will go into the struts. What I found was that there is only a few tenths of a millimeter tolerance. That is, my measurement suggests that the bolts go up to at least 0.3mm of the end of the tapped hole.

For a long time I've accepted that my Robot has a bit of "wiggle" between struts and base. But today I found that adding a washer to just one side tightened things up quite a bit. I think the strut is just ever so slightly underdrilled/tapped.

Since the force is primarily downward during a shot it shouldn't matter too much. But I might just pick up a second set of bolts and file them down a tiny bit. Why not.

I find that a decent pre-infusion time (caveat - I don't time mine really, just visually gauge things) followed by a slow pull that gradually builds to nothing approaching 9 bar works best for me, a dark roast aficionado. Also, I prefer bitter over sour every time.

So many paths...

I tend to skip preinfusion and bring down the hammer with darker roasts. And pull short of 1:2.

If your shots are sour I'd check if the temp of your water is hot enough.

I've had the Robot for 3 weeks on the counter exactly...and I have to say I like it more each passing day: amazing machine.