DavecUK I’m quite surprised… Overshooting is only a response from a pressure blockage at 2 bars, not a software issue. It’s obviously a physical thing. I’m talking, of course, about my machine but videos from kautivo seems to be very similar. Machine has to be hot, about 45 minutes iddle. No matter if you tweak pid settings or pump acceleration. Does it happen every time? No, not every time but unfortunately it’s very frequent. When it happens, coffee is spoiled. After this first ruined espresso, the circuir will be free of “extrange” pressure and next espresso will be fine. Always the same behaviour.
I know exactly what are you talking about when you are explaining this software things. I’m aware you have to learn to use this machine, profiling will depend of dosing, grind size, puck prep, tamping, etc. You may prefer a more agressive approach to profile steps or you may prefer a more softer approach (I do) looking for a mild curve. No difference, this is no related with this issue.
If you see my videos you can easily notice that there is a stop at two bars. Forget what comes next, just focus on this stop at two bars. This only happens when steam boiler is hot, over 125º aprox. If steam boiler is cold, there is no stop at the two bar mark and, just because this and no because software settings, there will be no overshooting.
My machine is from 2018, I’ve been using it everyday. Steam only for breakfast. It took quite a while to understand what was going on at first. Making lots of coffee, about 5 or 6 a day during this 5 years I have understand where the problem comes. How am I dealing with this? Playing with eco mode and not letting the service boiler to go over 120º before making the espresso. Do I think this is ok? Mmmm, no, I don’t think so. Machine should work the same way either steam boiler is ho or not.
video: you can see what I’m trying to explain when the counter hits the 8 seconds mark. This was a 10″ 2 bar preinfussion profile. The gauge is ramping up smoothly until this 2 bar mark. The pump has to “break” this barrier and the the overshooting arrives. This is very different from a software related overshooting, believe me, I understand what you are trying to explain.
130
With steam boiler colder, there is not any “stop”. You can notice how the gaude passes through the 2 bar arriving about 3,5 bars, this is for me the normal pressure my machine gets with a profile like this.
120
As I said before: my machine was serviced and repaired, quite a lot of spares where changed under acs supervision. Problem seems to be hard to solve. It seems if it is even hard to reproduce? Hope it works this way at my place!
Edit: words on bold letters, sorry, I wrote it will overshoots where instead of it will no overshooting!
