Vesuvius Pressure Profiling Machine - General Discussion

KKape17 · Mar 15, 2023

From another forum where Dave C used to be said (dated 2-16-2021) “If its a V sold in the last year or 2, then the Cruzet, who make the induction part of the pump for Fluid-o-tech changed the impulses per second parameters. This means the pump acceleration numbers may have to be far lower than the ones in my documentation… giving a smoother transition from one pressure stage, to another”.

I remember what I read in another forum Paolo from ACS recommended to lower the pump acceleration below 150 for those who have the Cruzet induction part if your pressure overshoots.

JahLaza · Mar 15, 2023

Kape17 thanks but I’m not sure this would explain what’s happening. Why would it jump to 15+ bar in the middle of a 2 bar step? Higher pump speeds attempt to achieve pressure changes faster. Why would it happen 50% of the time, and again half way through a 2 bar step that lasts 8 seconds

Edit: The settings I have listed above have worked using various profiles including the current one over the past months with no issue

JahLaza · Mar 15, 2023

I reduced pump acc to 330 this morning and shot pulled fine. Still don’t understand why it would suddenly start to jump in middle of a step rather than when transitioning from one pressure to the next.

DavecUK · Mar 15, 2023

JahLaza If for any reason it sensed a momentary reduction on pressure….bam away goes the pump. With high acc, it can peak super fast against a resistant puck.

A few pressure profiling machines which will remain nameless actually told you the pressure they were trying to make and not actually the pressure they were making. The Vesuvius tells you immediately and accurately what the momentary pressure is.

JahLaza · Mar 15, 2023

DavecUK thanks Dave. I get that logic, but strange that’s only happening now. The above settings had been in place for months now. I’ve used many types of profiles and lots of different bean types, the only time I observed funny operation was when it would either over shoot (not by much more than a bar or so) or not reach target pressure in a step. That would be rectified by changing the speed or kp value, but as I say the above settings had been in place with no issue for a good while, but shooting up above 15 bar half way through a 2 bar step just seems odd! Everything seems fine now anyway, thanks for you and other’s input (It’s a great machine😊!)

prezes · Mar 15, 2023

As previously said this happened on my machine as well twice or three times . Same as yours around year old.

Very odd and doesn’t seem right at all. The group pressure gauge didn’t register any increase in pressure and was showing 0 yet the pump was going at 15 bar .

I’m glad it didn’t happen for a while now.

prezes · Mar 18, 2023

In the recent weeks I noticed the pressure on the group gauge running around 1 bar higher than shown on display. I would normally ignore it but they were always showing perfectly same pressure since day one and remember reading @DavecUK post about this.

What could be the issue ?

Video a bit short as first shot of new beans so need to grind tad finer but basically when the display shows 8 bar the group is 9 as it falls to 7 the group will show 8 etc.

DavecUK · Mar 18, 2023

prezes As the pressure is equal in all parts of a system that is sealed, which the brew circuit is at the inlet end….the pressure differences can only be due to either the:

Software PID fluctuations that the system reads but the gauge doesn’t react to
Software PID fluctuations that the system doesn’t respond to, but the gauge does read
gauge reading incorrectly
pressure transducer reading incorrectly

As the gauge is a mechanical device, using a coiled bourdon tube, it’s never likely to be that accurate, or consistent across the range of readings e.g. it might be accurate at 5 bar, over/under read at 2 bar and 10 bar? They can also become less accurate over time.

What happens if you try it on a blind filter with the machine set to a constant 9 bar…

prezes · Mar 18, 2023

DavecUK thanks @DavecUK as said only picked up on it as it always read perfectly same so noticed the difference. Don’t want to be overly worried without reason but rather nip issues in early stages.

DavecUK · Mar 18, 2023

prezes I don’t think there’s anything to be worried about, the gauge perhaps overreading by 0.3 or 0.4 bar.

prezes · Mar 18, 2023

DavecUK great news ! Thanks Dave

John_Yossarian · Mar 19, 2023

prezes Since I have bought my V (three years ago) there has always been a difference between 0.5-07 bar but as @“DavecUK” mentioned we have two different systems of detecting the pressure so I decided this should not be out of the norm. The most important thing is, is your coffee what you expect/like it to be? 😀

prezes · Mar 19, 2023

John_Yossarian absolutely, coffee is great and that’s the main thing !

Only asked as mine always perfectly matched and only recently started noticing the difference.

JahLaza · Mar 19, 2023

prezes I would swap out the gauge on the group or get it re calibrated if I was worried or curious..?

prezes · Mar 25, 2023

I think I got to the bottom of this. This morning noticed the group gauge is sitting at around 0.5 bar when not brewing. I was sure I had a photo from last year to check if it was always like this and it wasn’t so definitely issue with gauge. Anything I can do about it or is it replacement only ?

DavecUK · Mar 25, 2023

prezes As I thought it’s the gauge..you can “try” twisting the outer shell a tad, but I think it’s keyed with a square piece, so it won’t adjust it….replacement is the only option I am afraid.

Note to self: “the OCD is strong in this one” 😁

KKape17 · Mar 26, 2023

DavecUK

prezes you can get a replacement at The Espresso Shop. Part # 5530011

Cuprajake · Mar 26, 2023

Do you need that gauge there?

prezes · Mar 26, 2023

I don’t at all but as it’s there it is bothering me ever so slightly being out !

I know what the issue is which is the main thing so might get rid or learn to live with it. I don’t think I’ll be replacing it

Cuprajake · Mar 26, 2023

Was that stock? I thought they had a grub screw in there?