marteccino wrote:...but does this mean that if spring resists initial 5 bars than all the pressure generated equals minus 5. So if pressure that ppl mounted on line into the boiler shows 8 or whatever, the puck is hitting minus 5 which is 3?

Yes. If it takes 5 bar to open the spring when you have zero bar on the back side, it will take 10 bar to give you 5 in the basket, 14 bar to get 9 in the basket, and so on.

marteccino wrote:My impression is that even tho the initial pressure requires 5 bars threshold, any consequent pressure generated by pump over that 5 bar equals what's hitting the portafilter since that small 5 bar spring no longer creates that back pressure perhaps once that threshold is broken....

Nope. If the pressure difference is less than the cracking pressure of the valve, the valve closes...

My guess is that it is closer to 2 bar than 5 bar, so that's not too much a difference in the end.

marteccino wrote:If it was generating that 3 bar it would be noticeable in the taste, but ppl compare these machine made espressos to fully fledged commercial or consumer made espressos.

I should add that I specifically mentioned finding the cracking pressure of the brew valve with a dimmer mod and noting the lowest possible pressure that any flow comes through the brew valve.

If you just turn the pump on with or without a portafilter, you may see a different pressure drop across the brew valve. I know that video showed roughly 5 bar with a blind basket, so it is possible on that specific machine that it truly took 5 bar to crack the brew valve, but this will not be the case universally.

Also. I've had at least six different SIN006 machines and a handful of other machines, ranging from the Breville Cafe Roma (worse in every regard than the SIN006 machines), a few Francis Francis! X5 machines (better in most ways to the SIN006), a prosumer HX E61, a fully plumbed two group commercial HX machine, and home machines with thermally stable saturated brew groups.

I enjoyed my Saeco machines when I had them.

I do not miss them. Yes. You can make great espresso with them, but the quality of life to get consistent results is nowhere near the same level. What coyote-1 is doing to their machine is admirable, and very likely and enjoyable process to them. I can relate to the ethos of taking something very modest and applying some ingenuity to get something that performs way above its price point.

But let's not suggest that anyone who finds one of these machines at a thrift store will have the same experience without the perseverance needed to understand the machine and take it to the next level.

Back to the pressure issue, I've been running my machine at 6 bar for about a year and I am perfectly happy with the results, so I don't think a large pressure drop across the brew valve is a big deal, regardless of the actual pressure number. Adjust the dose, grind and yield to get a beverage you enjoy, and you're done. I've pulled enjoyable shots at line pressure when my pump seized, so don't worry about it too much. Just follow your taste buds.

Cheers!

- Jake

Jake_G wrote:But let's not suggest that anyone who finds one of these machines at a thrift store will have the same experience without the perseverance needed to understand the machine and take it to the next level.

- Jake

While I agree with this statement, I also submit that spending $1500+ on a machine likewise does not come close to guaranteeing that a user will have great espresso! This forum and others like it are bombarded with messages along the lines of my new Appartamento makes nothing but sour shots or water stopped flowing from my Lelit or other such messages. And folks proceed to spend hundreds of dollars on an assortment of gadgets to fix their espresso, or they move from a Rocket to a LaMarzocco for many more thousands of dollars and expect that will fix their espresso.

I'm no genius, no magician. Nearly anyone can do what I did. A user could add the flow control dimmer, a $2 digital thermometer, modify the portafilter to unpressurized, and have truly enjoyable and consistent espresso. And it can be done on 'appliance' grade machines too.

In other words, regardless of what machine you have it's about perseverance and understanding. So I agree with your statement, and IMO it applies to virtually all machines. Incidentally, here's my appliance-grade 20 year old Krups with the flow control, thermometer, and unpressurized basket. While useless for steam, it nonetheless makes very good espresso:

coyote-1 wrote:While I agree with this statement, I also submit that spending $1500+ on a machine likewise does not come close to guaranteeing that a user will have great espresso!

I couldn't agree more!

One of the things that "working for it" with cheaper machines does for you is build the fundamental understanding of what it takes to make a machine deliver what you want in the cup. You find the quirks, and the work around techniques and learn your craft. You then know to take nothing for granted with any machine! The benefits of a machine with fewer quirks are only really appreciated after you've cut your teeth coaxing something great out of something so simple.

Cheers!

- Jake

Well I don't have pressuremetsr to measure it and when it was new noticed a mid extraction flow drop due to low pressure, but I haven't encountered it since, so there might be something variable with that pressure, but it pushes good when it has to.... and repeatability is hard, that's true. Have my machine only few months, but it was overally food experience, but boiler surfing was changing character and that I associate most likely with calcification since where I live water is hard, kettle has calcium residue after few uses, but due to the price of machine I don't and won't bother with filters or soft water (another huge benefit for me and less hassle).
But re boiler I had routine with waiting for it to reach "ready ok"temp, releasing steam and had 10 sec preinfusion and then had about 15 seconds when boiler light was ready. And coffee was great,
However that was only repeatable for couple of weeks. Last week this routine changed and kinda way I wanted to tinker with, which is that upon boiler reaching temp, release steam have that preinfusion 10 seconds, but already there boiler starts to heat up, instead of those 15 additional seconds previously, so now what it does is that during the extraction, the heating element is on, but this creates different crema, it's still thick and nobody would notice. But I see difference in its structure, because it's more sticky. Also coffee tastes slightly difference. It's hard to describe, but my metaphorical impression or how to say that is that while that heating element/boiler is on, perhaps electricity itself affects the water somewhat. The pump pressure is supposedly reduced too while element is on. First time using the pump changed noise while I was flushing while heating up, but now no longer can hear that difference, but was discussing here that pump loses slight pressure as interference. I probably prefer the taste it had before but it's still good. I wanna buy instant thermometer to measure all this,but can't find the right one.
Anyhow my opinion is that either element is calcified already or maybe the thermostat is affected by calcification too switching on sooner than before...
I already run 2x vinegar through it and no residue came out week ago but once I feel like it I will open the boiler and manually clean it since it's easy 4 bolts...
All in all as I said many times, no way in hell I would change this thing for another e61hx machine I had before for many reasons....I literally wish I could compare blind test this sub $100 plastic thing (what matters to me is it has stainless boiler inside) with lamarzocco Micra just for fun, I would probably wake up from my ego ride badly defeated, but I can imagine it could be a close call if I hit the right spot. ( It seems I have 1 great espresso from every 2 or 3 that are just good! But again I didn't plan to buy another machine but finding this thing (it's delonghi stilosa) discounted in supermarket for 65 euros new and non pressurized poltafilter and pro steam wand, I couldn't resist, because before I found it by accident, I was telling myself never ever another machine, only manual lever, but here we are having fun and convincing myself I am getting as good espresso as with any multiple times more expensive machine, probably wrongly so but until I have a wake up shot elsewhere, it's gonna stay

I also believe it's very similar to that saeco. Similar boiler, spring,etc...that's why was kinda treating it but of course saeco better quality! But it's not produced anymore.

(Notice the narrow steam wand. All other machines in this category have the plastic thing. It's probably not sold in US, idk)