Londinium 1 extraction issues - Page 5

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espressotime
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#41: Post by espressotime »

LObin wrote:I will definitely measure temp in the cup tonight. I did read about TS stall and always flush after a shot. I also tried a half a second flush prior to locking in the PF.
I have left my machine on for anywhere between 16 and 48hrs. Never less...

I do however hear a little water sound that seems to be coming from the TS. Not sure if it should be silent or not. I bleed the air of the TS twice but it's still there. Thought it might be the water cycling in the TS that I'm hearing...
Maybe someone with an L1 can comment on this?
Reiss should know all you need to know?

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another_jim
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#42: Post by another_jim »

LObin wrote:IThis leaves me with 2 possible explanations:
1. The modern lever group is way, way to fussy compared to traditional designs that have stood the test of time.
(Read Paul Pratt on this matter...)
Isn't the Astoria group on the 3000 modern, with the same cylinder and springs as the Bosco group in the Londinium?
Jim Schulman

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LObin (original poster)
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#43: Post by LObin (original poster) replying to another_jim »

The CMA cylinder is a tad narrower and longer. Piston has 3 seals but is a little different whitout the plastic ring.
My group has the external double bearings and plastic top casing. I wouldn't know about the spring.

Isn't one made by CMA and the other one by Rossi?

Also, the portafilters are different. There is more space above the wings of the bezzera vs the Londinium.
Pop-on shower screen and round pf gasket vs E61 shower screen and 6mm(?) gasket.

The CMA group seals slipped on the L1.
LMWDP #592

walt_in_hawaii
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#44: Post by walt_in_hawaii »

My L1 is silent if the vibe pump is not on and the boiler is at stable temp. Tank, not plumbed in. Set at 1.1-1.2 bar.
I never go over 16g in the L1, although the Strega seems happiest near 19g. both will pull excellent doubles although the L1 is happier with ristretto ish shots.

Pino
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Joined: 19 years ago

#45: Post by Pino »

As mentioned a bottomless porta filter may help here. Recently I was getting half the basket (looking at the bottom of the basket during extraction) with coffee coming out and the other half just had beads of coffee. So looked like only half of the basket was being extracted. The result was an under extracted shot.(may have been similar to yours)
Unlike a previous comment, that the L1 is not forgiving, I was getting the opposite impression. To try and solve that problem I would increase the setting on the HG-1 by one increment every time I made a coffee. I have increased by six steps and now extracting across the whole bottom of the basket.
However (to complicate) just yesterday started to use an IMS 200 micron screen, which appears to have helped a lot by making the extraction uniform.
Numbers: 15.9 grams coffee(nickel barely leaves an impression indicating a nickel width between coffee and screen)
25 gr wet. 15 - 20 sec wetting; 25 - 30 sec extraction.

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Almico
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#46: Post by Almico »

LObin wrote:I do however hear a little water sound that seems to be coming from the TS. Not sure if it should be silent or not. I bleed the air of the TS twice but it's still there. Thought it might be the water cycling in the TS that I'm hearing...
Maybe someone with an L1 can comment on this?
I flush after each shot. I hear a faint {pish} which sounds like the TS topping off. Other than that, no sounds that I can notice.

I've never used Cafelat seals, but I did try the portafilter gaskets. They did not hold up well in a commercial environment and tore up fairly quickly. After that experience, I would not use them for piston seals. The hard rubber ones are a pain to install, but they work great.

LObin (original poster)
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#47: Post by LObin (original poster) »

I might have been a bit quick to come to the conclusion that my group is running at a proper temperature. I contacted Reiss and will investigate further more. I'll report back.
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Paolo
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#48: Post by Paolo »

A stick-on thermometer strip is all you need to ascertain group temperature. I have one located on the group just above the bottom lip. It is approximately 35mm above the bottom of the group.

To get a great shot with this group (temperature-wise), just make sure that the temperature is at or above the 70C rectangle on the thermo strip.

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Paul_Pratt
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#49: Post by Paul_Pratt »

LObin wrote: Higher PI? But then I would notice a difference with active PI with the L1...
Open loop TS vs closed loop?? Maybe. But again, with all the different successful design in lever machines, this can't justify such differences in shot quality.
This leaves me with 2 possible explanations:
1. The modern lever group is way, way to fussy compared to traditional designs that have stood the test of time.
(Read Paul Pratt on this matter...)
2. The issue is pressure related. It will be resolved with better seals and shower screen.

I'm not taking the amateur barista (me) off the equation. I'm just looking at the only variable that has truly changed... the machine.
I would refer to Jim's quote from David Ross. Pressure and water temp.

The group works fine I merely tried to highlight the fact that the piston could be better and for some unknown reason people try and complicate things more than they really need to. Fracino are 1st rate manufacturers and Reiss does know his stuff so it is unlikely the machine is the culprit unless it has debris or limescale blocking it.

The best way is to borrow a scace 2 and see what is going on. And experiment.
Almico wrote:I've never used Cafelat seals, but I did try the portafilter gaskets. They did not hold up well in a commercial environment and tore up fairly quickly. After that experience, I would not use them for piston seals. The hard rubber ones are a pain to install, but they work great.
That is unusual to hear as we get nothing but praise for the silicone group seals. I will say though it does take time for baristas to adjust to not having to really crank in the portafilter to get a seal and to make sure no sharp tools are used to install them.

LObin (original poster)
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#50: Post by LObin (original poster) »

I appreciate your contribution Paul. Sure enough, Reiss asked me to get some temperature readings as well since he's suspecting obstruction in the TS circuit, most likely caused by scale.
LMWDP #592