Solis Barista Perfetta - Design issue or channeling

Need help with equipment usage or want to share your latest discovery?
Rene-java

#1: Post by Rene-java »

Hi all,

I am new to this group. I received the Solis Barista for Christmas and have been working to improve my espresso shots with this machine. I have noticed that the machine produces 2 divots (like when a golf ball lands on a moist green) in my pucks.



They are always located in the same place in the puck. I believe the divots are being produced by two streams of water that come through the screen while the rest of the water tends to drip or gently pour from the rest of the screen.



My question is whether this is a problem and is it impacting the extraction process? I called the seller but they were not able to receive my media and so they insist that it is a channeling issue caused by my lack of skills (my interpretation of what they said). But I feel that in this case the pictures may tell a different story so i thought i would get some input from this group. Thoughts?

checkwhatsleft

#2: Post by checkwhatsleft »

It's likely that was puck prep caused it.

User avatar
Jeff
Team HB

#3: Post by Jeff »

Another possibility is that they are due to how the water leaves after the shot is complete.

JohanR

#4: Post by JohanR »

I had a similar problem which I resolved by rotating the puck screen and the dispersion plate such that the holes do not line up with the outlet from the group head itself.
Johan

captain_walnut

#5: Post by captain_walnut »

Hi there, was this issue ever resolved? I've noticed the same thing with my Perfetta, regardless of puck prep. I wonder if indeed it is actually due to how the 3-way solenoid pulls off water at the end of the shot, or if I need to adjust the dispersion sceen.

User avatar
cafeIKE
Supporter ❤

#6: Post by cafeIKE »

Stop the shot about 5 seconds after the pump starts and have a look. [I don't know anything about the machine, so you may have to pull the plug]

Rene-java (original poster)

#7: Post by Rene-java (original poster) »

Hi Captain,

No, it was never resolved. I tried adjusting the screen (not sure i would call it a dispersion screen as its just a screen, no real dispersion designed into the screen) and it created one hole instead of two holes. I tried to send pictures (the ones posted here) to Seattle coffee to get their input but they said they never received any of my emails. I have given up of fixing the issue as I think it is just part of a cheaper machine. I have kept my machine and i am happy with it as I upgraded from a 10 year old Breville cafe roma predecessor which is totally manual.

Good luck with yours and post if you find a solution.

mikedp

#8: Post by mikedp »

I'm new to espresso and bought this machine as it seemed a good starting point.

I noticed the apparent channeling per the photo in the OP, so after a few months I had a proper look. (BTW I'm a retired engineer, so solving things like this is fun.)
I thought it was likely due to the way water was fed to the screen, so I removed that and there are two ports, plus moulded channels in the head. Looking down on the machine, or basket there is a smaller port at about 12 o'clock and a larger at about 4 o'clock. The channeling indents occur at the 12 o'clock location, so I think this is the water feed port and the other, larger, is the pressure relief port.

My theory was/is that the water port tends to jet liquid through the screen holes under it, while other water has to turn a right angle and follow the channels to get to the rest of the screen.
Possible solution - block the holes under the port (water will find it's way to the area underneath anyway).

I thought about thin plastic but I think the screen needs to be tight to the head for the channels to direct correctly, or at least as they do now, and changing that could lead to other unforeseen consequences.
So my applied solution is:
Remove and clean the screen.
The injection port centre is ~12mm from the centre, so I chose a radial line of holes and found the one closest (2nd or 3rd from the centre IIRC).
Include the holes around this one and mark just outside - this gives you a square of 9 holes.
Block these 9 - I used a little bit of 2-part epoxy (Other stuff might do but it needs to be able to cope with hot water) pushed into the holes and spread thin from both sides.
Once fully cured I used a pen to mark the row of the middle hole and also on the machine the line of the port, then refit the screen making sure the blocked section was under the water port.

I've only done a few extractions but there is a noticeable difference. No holes in the puck, the crema is not 'paling' out like it usually did and I think (I haven't timed it) the extraction is running longer.

I don't yet have the experience to say the taste is better and I've only used it for milky drinks so far - sorry.

mikedp

#9: Post by mikedp »

My patch as described above has not worked out quite as hoped. As the screen is only held with a centre screw I knew it might turn and misalign the patch, but as it's a clearance fit in the basket I had fingers crossed.
However after a few uses I noticed some dimpling/channeling in 'that' location and it looked to me that the screen had rotated a little.
So I've just done a bit of engineering and fit a small screw to stop it rotating. I'll report more on that when I've seen how it works out in practice.

mikedp

#10: Post by mikedp »

mikedp wrote:I'll report more on that when I've seen how it works out in practice.
I think I've got it sorted now.
First iteration of the screw was in the water port (as that was where I was blanking holes it was easy to judge the position) but there was some disturbance of the puck surface and maybe channeling nearby. I think the presence of the screw was making the water 'jet' a bit (like putting a finger over a hosepipe).
So I moved the screw to the larger port. This is a bit trickier as you need to ensure the relative positions of the screw and blanked holes are the same as the two ports. This seems to have worked well with no significant or consistent dimpling or channeling in the surface of the used puck. (The centre area where the main screw is is always a little raised as you'd expect.)

The trouble is this makes it a much harder mod than just blocking a few holes. I used a 2mm brass screw in a threaded hole in the screen, protruding 4mm above the screen to engage the port and sealed in place with epoxy. I then used a mini drill to cut the part of the screw below the screen off and smooth it, and to taper the top part a bit where it is in the port.
Just drilling the s/s screen is not trivial, and most won't have the tools and parts to do what I did, but it might be possible to just epoxy something to the top of the screen to locate it. Success would depend on how well the epoxy lasts and how much rotational force is applied to the screen when the handle is being turned to fit/remove the basket.

Anyway, I hope that at least adds something to the knowledge. :)