Time for an upgrade - Page 4

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puffinjk
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#31: Post by puffinjk »

Silicone gaskets being more flexible do tend to absorb quite a bit more variation without leaking, Great machine you have there. Jim

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EddyQ (original poster)
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#32: Post by EddyQ (original poster) »

Thanks all,

So this weekend I obtained new group gaskets, installed and pulled a few shots. The old gaskets were in fact very hard and at end of life. The naked PF did seem to seal for a few shots, but this morning I had a minor leak. Applying slightly more tightening pressure fixed and saved the shot. So, I think the new gaskets have made things much better. The PF does need fixing IMO and I plan to do something in the next week.

I measured the new gaskets and they seem to be identical to a Cafelat Silicone gasket. So I may go ahead and order silicone gaskets for the future.

I also picked up new sets of piston gaskets. So in the next week I hope to dig into the piston and make them like new.
Meanwhile, I'd like to wrap my head around a few new baskets (rimless) to order. The 20gm VST is working well, but I hate the rim. I may go ahead and order a EPNW HQ21.
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Balthazar_B
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#33: Post by Balthazar_B »

Not familiar with the Idro to know whether those two portafilters are the ones that originally came with the machine, but it's hard to see how Kees would let one out the door that has the obvious flaw yours does. If you talk to someone at Espresso Parts -- I've gotten good service from Dave Merkin -- ask whether they have any portafilters in stock that are absolutely, positively guaranteed to fit your rare machine (there are no one-size-fits-all portafilters, especially the ear fitment). Even if you take a grinder and try to fix your flawed one, it's always good to have a backup.
- John

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EddyQ (original poster)
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#34: Post by EddyQ (original poster) »

Well, I sandwiched the PF between two thick, flat plates in my vise with thin shims and managed to bend the PF almost perfectly back to being flat. And this technique did not make a mark in the chrome plating. Plus, it seems to work great now.

I suspect this PF was significantly over tightened in its past that resulted in this condition. I very much doubt it can from KvdW that way.

Today I replaced both groups piston gaskets. Yeah, the old ones were far past end of life. Brittle and likely failing to seal. The job of replacing them was rather simple. I did't have to shut down the boiler to do so. Just flip a valve, purge and pull the piston after it cooled a bit.

Today, I also made an attempt to measure brew temps with my Amprobe logger and a thin thermocouple over the puck. It leaked a little, but I got some indication of temperature. Tomorrow I plan to redo these measurements with new piston gaskets. I don't suspect temps will change, but preinfusion will since with old shot gaskets preinfusion started early. I'll likely have questions about brew temps soon!
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EddyQ (original poster)
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#35: Post by EddyQ (original poster) »

LONG POST . . .

So it is approaching a month since I pulled my first shot with the Idro. And shots most to date have been quite disappointing. Not that I did anything wrong with preparing the shot, but temperature management has been a challenge. I'm finding this machine is NOTHING like any other discussed on the internet.
I started with the assumption that the previous owner had the boiler temperature right (matched the owners manual of 257F, ~1.25bar), 3bar line pressure per owners manual and left the thermosiphon adjustments as is. I placed a group head thermocouple about 1.5" up and at 2:00 position (close to back of group) and the long term idle temp (with no PF installed) held 180F. This seemed a little high relative to many Bosco group temps published here on HB. BUT, my shots were coming out hugely sour! So, I increased the group temp 5 degrees by adjusting thermosiphon flow. This worked, but my shots were not consistent and off in many ways.
What makes this machine much more different than a Bosco is that it has a throttled thermosiphon HX. I read many things in the past weeks about HX machines and the need for a HX flush after an idle, but most of these machines are E61 groups and the water comes out way too hot at first. This Idro doesn't ever have flash boiling water come out after a long idle even with a hotter adjusted thermosiphon. My Idro has a special optional flush feature from KvdW. According to the manual, I am supposed to push this button and a solenoid flushes the perfect amount of water from thermosiphon without altering the group temps. Seemed to be ingenious with knowledge from other HX machines. But, there was no mention in the manual how much time I am to wait to pull a shot. Based on HX E61 threads here on HB, I concluded I should pull rather quickly (like <30s) after a flush. But that was NOT working out. More very poor inconsistent shots. And longer, like a minute or two also proved to not work out.
This weekend I decided I needed to attack the thermal problem with a series of tests. For starters, I needed to be certain my group head was stable. The boiler has an electronic (manual says thermostat, but I think it is a PID) boiler control. It senses boiler temps in steam above liquid. The manual says this results in better thermal management when steaming. The boiler is a whopping 14 liters, so it is pretty stable.



I ran my Amprobe TMD-56 for 9 hours over night measuring group temp and room temperature. I think this plot shows I have no concerns of stable group idle temps. My room fluctuated between 63 and 67 and my group held within a half degree.



Next, I really needed to measure brew temps. I do not have a scace or shomer basket. But I do have a very thin wired T-type thermocouple which I lap over the basket rim when pulling shots. This proved to be a bit challenging to get good seal and stable thermal measurements. And how to make stable measurements shot to shot? After more research, I found a technique that helped quite a bit. Basically, I ground coffee quite a bit finer than usual which almost choked the machine. Pull the shot and the flow increased with next reuse shot. I found the right grind that resulted in near perfect flow for 10s preinfusion and 25-30s shots repeatedly without removing the thermo probed PF. This approach was not flawless. The repeated pulls start with different conditions than that of real shots. The coffee is wet and hot. The PF is hot. However, the thermoprobe doesn't move, which I feel is more critical. To help even more with probe placement, I sewed the probe to a aeropress filter and placed sandwiched between two filters. This stopped the probe from digging deeper into the coffee bed and held it close to coffee in middle of basket. I think it worked pretty good. Below is data from repeated 10s preinfusion, 27-30s pull followed by 2min wait. The beginning was a stable group temp after long idle (many hours of stable group with no PF).





The data collected showed the group does heat and stabilize from 188F after long idle to 190F after 5 or more shots. The group peaks at roughly 193-194F immediately after preinfusion which is worth noting.
At this point, I likely have dialed my throttled thermosiphon in the ballpark to being correct for pulling many shots based on peak brew temperatures. However, I have not yet tasted any shots after 5 multiple shots. And again, I am assuming the hot PF with wet hot coffee will have a small effect. So, the final temperatures will likely still need to be tweaked based on taste. But I am pretty pleased at the results. The stability shot to shot looks pretty good after 5 shots. The temperature across the shot looks to nicely decline 3-4degrees.





Ok, so I am still struggling with the right "song and dance" I need to do every morning for my first shot and then the proceeding 3-4 shots. I played around more with the machine flush option. The temperature data seems to show this flush does nothing but lower the thermosiphon temperature from a point which isn't too hot to a point that is too cool. And it also seems this drop of thermosiphon temp drops the shot temps for the first 15s. This feature seems pretty useless unless I am still not using this it properly. So, I decided to manual flush through the group while monitoring the group temps. My assumption is that if the group temps match the long term group temp profile, then we are ready for pulling a shot in 2 minutes. This takes a flush of about 100mL and then prepare shot for 1-2min and pull. Above are temp plots where I pulled a shot this morning, Ethiopian Hamela Natural (very fruity), where I flushed somewhat slowly til group temp hit 195F, then proceeded to prepare the shot. 1 min later, the group temp had fallen to 190F and installed PF and pulled the shot. 10s preinfusion, maybe 30sec shot time. The shot was best yet! Nice sweet fruit bomb with no lingering bad after tastes. But the peak group temp never was as high as 5 shot temps and I think this might be because the thermosiphon look and HX still had not recovered to full temperature. Perhaps next times I will wait a bit longer, maybe full 2min before pulling the shot. Perhap my next steps are to put a probe on my thermosiphon pipes with hopes that will aid with the first few shots.
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drgary
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#36: Post by drgary »

Ed,

I wonder if the prior owner had it working well. A quick call might help you dial in.
Gary
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What I WOULD do for a good cup of coffee!

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EddyQ (original poster)
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#37: Post by EddyQ (original poster) »

drgary wrote:I wonder if the prior owner had it working well. A quick call might help you dial in.
Relative to the "flush feature", I did talk to the original owner. He said he didn't find the feature to do anything and it cost him a bundle. The previous owner (who bought the shop from original owner) let me pull a shot before I bought. It was an Onyx Lab roast and I did not catch which one. It tasted pretty good pretty chocolatey with hints of fruit. I suspect it was a darker roast than mine.

The two groups were 5 degree different from each other. The right being hotter. Now, I have it 10 degrees hotter than the left. With the original settings, my Ethiopian Habela tasted like an unsweetened fruit drink concentrate! Wow what a mouth puckering experience. Right now, I am close to dialing it in (I think). Still working it.
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Pipeandslippers
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#38: Post by Pipeandslippers »

This is such a fascinating thread. Do you know why KvdW stopped making lever machines? I don't really believe it was due to fear of liability should someone hurt themselves with one. There are plenty of other ways to hurt yourself with a coffee machine. Simply that there wasn't enough demand for them? I wonder why that would be.

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JohnB.
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#39: Post by JohnB. replying to Pipeandslippers »

Kees told me that Idro production was too labor intensive/time consuming vs the demand. They needed production time & space for the Spirit. The liability issue was why he wouldn't build a single group Idro & that came directly from Kees when I inquired about ordering one.

Eddy - I have an email from Kees archived that describes the Idro timed flush option. I'll try to find it & see if he offered any info you don't already know.
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truemagellen
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#40: Post by truemagellen »

Can you make a video of your technique? From start to finish?

I have found for light to medium roasts (not super light) on a big commercial lever that the niche needs a bit longer preinfusion of several seconds. To do this well grind a bit finer and stir in the basket not in the cup.

Perhaps someone can come over who is familiar with large levers and bring another grinder for comparison and just have a jamm session so to speak trying things to get it right.