The volumetric dosing on my Mini Vivaldi II has always been inconsistent (with or without portafilter / coffee in place), but I don't know if this is typical?
I programmed one of the buttons to 58 grams, without portafilter in place.
I ran the shot 6 times (still no portafilter) and got these results:
58g, 8.5 seconds
52g, 8.7 seconds
55g, 8.7 seconds
40g, 8.8 seconds
45g, 9 seconds
73g, 8.6 seconds
The times are consistent, and not completely accurate as measured by me with a stopwatch. The weights out are obviously quite variable.
Is this normal / expected? If not, what should I be looking at in terms of parts or other possible problems?
Inconsistent volumetric dosing
Re: Inconsistent volumetric dosing
Did some more testing, immediately following a backflush.
The times are always the same, around 9 seconds.
1. 82g
2. 55g
3. 72g
4. 59g
5. 59g
6. 59g
7. 38g
8. 80g
9. 63g
10. 40g
11. 78g
12. 45g
13. 77g
14. 48g
As the pours take the same time, there is a noticeable difference in flow rate. It also seems that when I get a short pour, the next one will be long to compensate.
Adding the weights of the short pour and the following long pour, they generally average out to 60g (the volumetric target).
Eg:
Pours 7&8: (38+80)/2 = 59g.
Pours 10&11: (40+78)/2 = 59g.
Pours 12&13: (45+77)/2 = 61g.
The times are always the same, around 9 seconds.
1. 82g
2. 55g
3. 72g
4. 59g
5. 59g
6. 59g
7. 38g
8. 80g
9. 63g
10. 40g
11. 78g
12. 45g
13. 77g
14. 48g
As the pours take the same time, there is a noticeable difference in flow rate. It also seems that when I get a short pour, the next one will be long to compensate.
Adding the weights of the short pour and the following long pour, they generally average out to 60g (the volumetric target).
Eg:
Pours 7&8: (38+80)/2 = 59g.
Pours 10&11: (40+78)/2 = 59g.
Pours 12&13: (45+77)/2 = 61g.
Re: Inconsistent volumetric dosing
Hey Jon,
Saw your post & it got me thinking. I’ve had my Dream T for a month now. I really like the machine overall. I have just started setting up the volumetric dosing as part of the various user profiles. I’m seeing some inconsistencies too.
I set a dose for one of my main coffees today. With 17 gr coffee in the PF, I’m pulling 28-29 gr out in 27 sec @ 201 deg.
I emptied the PF and tried measuring the water mass without coffee in the PF.
Like you found, my run time has been pretty consistent @ 15-16 sec. The first volumes were 142, 146 gr. Consecutive shots kept climbing in volume ranging from 155 gr. - 173 gr. water. I paused a couple of minutes between shots so that the boiler could get back up to temp.
These variations seem like a huge difference in volume. Explains why when I think I have a volumetric dose set right, the next shot or two is either too short or too long.
I guess I’ll give Chris Coffee a call and ask them what’s going on.
Saw your post & it got me thinking. I’ve had my Dream T for a month now. I really like the machine overall. I have just started setting up the volumetric dosing as part of the various user profiles. I’m seeing some inconsistencies too.
I set a dose for one of my main coffees today. With 17 gr coffee in the PF, I’m pulling 28-29 gr out in 27 sec @ 201 deg.
I emptied the PF and tried measuring the water mass without coffee in the PF.
Like you found, my run time has been pretty consistent @ 15-16 sec. The first volumes were 142, 146 gr. Consecutive shots kept climbing in volume ranging from 155 gr. - 173 gr. water. I paused a couple of minutes between shots so that the boiler could get back up to temp.
These variations seem like a huge difference in volume. Explains why when I think I have a volumetric dose set right, the next shot or two is either too short or too long.
I guess I’ll give Chris Coffee a call and ask them what’s going on.
Re: Inconsistent volumetric dosing
I also have the mini vivaldi 2, and getting inconsistent shots. I measure my double espressos, and with same bean/grind/dose it can vary 3-5 grams per shot.
Re: Inconsistent volumetric dosing
I spoke with Chris Coffee today. They are going to test their Dream with & without coffee and get back to me. I’ll post what I find out.
Re: Inconsistent volumetric dosing
Any update?
I had similar inconsistencies with my Breville Oracle
it got to the point I stopped using volumetric dosing.
I'm hoping that's not the case for Dream's too.
I had similar inconsistencies with my Breville Oracle
it got to the point I stopped using volumetric dosing.
I'm hoping that's not the case for Dream's too.
Velcro
Sette 270
La Spaziale Dream v1.24
IMS Baskets & Reg Barber C-Flat 53.3
Sette 270
La Spaziale Dream v1.24
IMS Baskets & Reg Barber C-Flat 53.3
Re: Inconsistent volumetric dosing
The volumetric dosing on my mini Vivaldi II didn't work at all from day 1. Based on what I read here I stripped it down and removed the usual brass shavings from inside the little doser spinner thing, and it has worked perfectly and consistently ever since.