Katoci wrote:I'm playing with it a few weeks for now and really like it. Experiencing with different pressure profiles surfaces the same coffee's different faces (subtle, but definitively noticeable differences). Still need a lot of time to learn how to use it's full potential.
I see you are hitting 9 bar on your pull. It is very interesting because I have learned this week that my "muscle memory" Cremina shots hit a maximum of 6.5 bar or so and then slowly decline from there. This is something that I did not expect.
I'm having a lot of fun learning "what 9 bar feels like" and "what 3 bar feels like."
I'm playing with some new profiles too, such as "preinfuse at 3 bar for 10 seconds, then ramp up to 8 bar and pull the shot."
Previously I had found that preinfusing at specific pressures was pretty much flying blind, especially since at that stage there is no flow to watch to help you know whether you need to let up or lean on it.
I've liked my Cremina as long as I've had it but I've never quite been able to make coffee sing with in the way that I can with the President. This pressure gauge may change all that.
As far as assembly goes, it took me about an hour from start to finish, although I did have some hiccups that others probably won't have, such as a lever pin stubbornly refusing to remove itself, and the fact that I lost my snap ring pliers and had to get creative.
Naked-Portafilter has an "assembly" video which I followed; it is pretty good but since there are no textual instructions (at least not yet) I can list a couple "gotchas" I encountered.
First of note is that you will want to have your own piston seals available in case they need replacing or one breaks while you are removing it from the old piston. The kit does not come with its own piston seals. It does come with a piston fitting ring however which is extremely convenient for getting a piston with new V seals back into the group. I wish I'd had this thing 4 Pavoni restorations ago!
Second: I want to take some time to clarify this part since its not made obvious in the video, and its the one thing that caused me a bit of grief even though the fix wound up being rather easy. After you insert the new piston and shaft into the group, there is a small brass washer you insert into the top of the piston shaft and then you screw in the pressure gauge mount. Screw the mount in very tightly, and make sure you don't unscrew it when you are adding the pressure gauge. This can happen if you aren't paying attention while fiddling with the pressure gauge to get it to lock in at the correct angle. I made that mistake the first time around and got a slow leak out of the base of the mount. The fix was very simple: re-tighten the mount.
Here is an image of the shaft with the pressure gauge mount screwed in. The part at the top is what actually controls the tightness of the mount. The two nuts at the bottom have nothing to do with the mount or the seal. They are simply there to control how far the piston is allowed to travel down the shaft. Essentially they simulate the "shaft cap" that used to be there on the original shaft.
Lastly: If you bend a snap ring taking it off, don't use it to hold the new lever pin in place. Due to the design of the piston pin braces, a bent snap ring will pop off when used.