Cafelat Robot and DF64 grinder making 10 second shots

[Grantmasterflash]

Hello, I have a Cafelat Robot which up until recently I was buying espresso beans preground from my local roaster. About 25% of the time the grind was correct and the espresso was spot on - 16 grams of espresso, 60 grams of water, 30 second pull with about 34 grams of output. The other 75% of the time the grind wasn't right and it's really hard to just feel it and tell if it's going to be good.

Soo, I bought a DF64 with SSP Sweet Cast burrs to solve the inconsistency problem. Not knowing where to start the grind I zerod the pointer and ground at 35 which felt similar to the grind from the roaster that is currently working. Water shot out so fast that it drenched my counter.

I dropped it to 26 and the same thing happened.

Then to 10 with the same results

and finally to 3 (basically powder). This time I got a little pressure and then boom, straight through.

The last puck had a large channel right through the middle. The other pucks came out in one nice solid piece.

I'm suspecting that the puck is lifting and the water is going around it. Anyone else with a Cafelat Robot and your own grinder that can give me some tips? Thanks in advance.

 

[Lindsey]

This sounds like a grinder issue, not a Robot issue. I also just recently acquired my setup which is similar to yours. Robot and DF64. I didn't upgrade the burrs though.

Did you check the burr alignment? I can tell you that, out of the box, my burrs were horribly misaligned. At the finest setting, it wasn't grinding fine enough for espresso and water was shooting straight through. Obviously, the grind also lacked uniformity. Most people seem to have no trouble with the bottom burr and can fix misalignment by rotating or shimming the top burr. In my case, I did have to shim the bottom burr. Once that was fixed, my grind range for espresso was much wider and the resulting coffee grinds were very uniform. If I had to guess, your issue is misalignment. There are several videos on how to check and fix misalignment.

Hope this helps!