'New' Rancilio Epoca single group ST1

FreshCoffee2

Hello Pat. In the first post you mentioned modifying to a "procon vibrational pump", and in the second you just mention procon. KISS. Leave it alone. There is no advantage changing from one brand pump to another, except if the first one is stuffed and needs replacing. I have never heard of a procon vibrating pump....in any case....see the previous couple of sentences. Usually when people refer to a "procon" they are referring to what has become on the WWW, the iconic market leader BRAND in rotary pumps. We see all manner of pumps (there arent many brands by the way) in machines here, and if they pump water at a specified pressure, then they are operational. That's it. I will be happy to sell you somehting with the name Procon on if you like, but I will definitely be the winner there! 😉 Also when people talk about that stuff, all they really mean is to change to a water connect...if they know what they are talking about! Reiterating, forget about pump brand names and leave it alone. If your pump (whatever it is) is working....then its working and a change to another brand name will achieve absolutely zilch. The other thing about pumps, is the never ending internet discussion between vibrating VS rotary (irrespective of brand name) where rotary is purportedly "better". An internet myth. I've authored something elsewhere that I might lift and repost here....after all...its mine! WRT your machine, use and enjoy. Hope that helps. Attilio very first Crema site sponsor EDIT: AM, it seems you chimed in while I was writing my own reply 😉

beanflying

Like the others leave it alone 'unless'. Noise aesthetic if your going to use this at outside functions like your old machine then vibe pumps are more noisy. 2nd if you are going to be puling from an under bench water tank then vibe pumps won't do that very well at all and that's were a second diaphragm pump sometimes is sometimes called for (going to cost 1/2 a new procon to do). If it were me in this case I would simply do as you are suggesting remove the existing ukla or whatever it is from the water and electric circuits (leave it in place in case you sell the machine). Then get Josh to drop you an external Procon (put it beside the tank) but have it wired back yo the machines controller. Dial up the pressure relief valve to suit zero input pressure rather than a more normal plumbed in 2-3 bar and make coffees 🙂 As to the ripple with a vibe pump at 50Hz if you can taste the difference you would have to be the super taster to end all super tasters 😃

FreshCoffee2

Ok if it helps, here it is: I wrote it elsewhere but I stress.....I wrote it. ".................... With regard to the diff between vibe/solenoid and rotary pumps: Simply put, the difference lies in the capability of the different type pumps for volumetric delivery. EG: A vibe pump in a 1 group machine = no worries. A vibe pump in a multi group machine = cant deliver the volume if you have more than 1 group operating at the same time ( or the boiler auto fill). A rotary pump in a multi group machne = no worries. What's the real difference then? Ability to pump volume in multi group machines. Vibe pump machines can be and are in various circumstances, hooked up for mains water operation but again (in my experience), only in single group form And..... If you built a multi boiler machine that had an individual vibe pump for each group as well as the auto fill, it would operate as well as a machine with a rotary pump. Or.... If someone built a vibe pump that was physically larger than the current type, it would pump more volume....... But of course the fact is, why bother with all the extra design and build, when a rotary pump can already do the job? What is he only other real difference that I can see then? Smoothness and noise level during operation of the pump. The rest, is nothing more than web based myth, very often perpetuated in sales pitches to get clients to buy one machine over another..............." After that. If you want a rotary pump machine, its far easier to just buy a machine that comes as standard, with the rotary pump, otherwise in addition to the issue of how to modify the plumbing to suit, there is the very real space issue of where to put it (machines with vibe pumps usually have a smaller body because the extra space that would be taken up by the motor/pump, is not required). And wrt BF comment above: "...As to the ripple with a vibe pump at 50Hz if you can taste the difference you would have to be the super taster to end all super tasters...." Spot on and once again thanks to Crema participants for having common sense (just that I would have called them super cuppers rather than tasters! 😉 Hope that helps. Attilio.

UNM

just curious. rotary pumps have a built in adjustable over pressure valve. Can the vibe flutter cause issues with the simple spring opv used in most espresso machines designed for domestic use?

FreshCoffee2

Some will differ but I really dont believe so. You adjust (where there is a means to) the bypass on a vibe pump, and it does the job! By the way what everyone seems to call OPVs when in relation to these water pumps, are actually bypass valves. Most dont realise that the pumps just pump at their full rated pressure and are not actually adjustable. The pressure relief is in the bypass. In the case of vibe pumps the bypass is external to the pump body and with machines that are not plumbed, that resulting bypass goes back to the water tank reservoir. In a rotary pump the bypass is across the outlet and inlet sides of the pump ie, the water bypass goes back to the inlet side and goes back into the pump with the fresh feed. You are adjusting the outlet bypass (basically as with a vibe pump) when you turn the screw in the adjuster......not the pump pressure produced by the pump itself which as stated, remains static at its maximum rated pressure. Just one of those little points!

askthecoffeeguy

well that about answers it for me then _ i'm still yet to pull a shot on this beastie as the side cover 'fell' off when I picked the machine up at purchase (yes its a second hand machine from flea bay but I've had it looked at and described as being in 'as new' condition - the machine that is - not the side panel) Considering its pretty much just a good looking S24 (which is my old machine) under the bonnet, and I loved the coffee that the s24 produced - I'm going to go with the advice of if it aint broke dont fix it I personally prefer the tank version for a multitude of reasons not the least of all being: a) there's no room in my kitchen for a plumbed in version, and b) I love the convenience of the tank when it comes to small catering jobs - all I need is access to a waer supply and I can do all the rest Should have the side panels fixed by friday and be pulling shots at home on the weekend!

askthecoffeeguy

well the machine has had the covers off and a good clean and descale, the shower screen was filthy - I mean really people looking after your coffee machine should fall in the same category as personal hygiene and should be compulsory and become second nature! anyway, covers go back on today and side panels should be fixed as well - which means fingers crosses this little beastie should be on my kitchen bench tomorrow! 🙂 🙂 🙂

beanflying

Fresh Coffee wrote:

Some will differ but I really dont believe so. You adjust (where there is a means to) the bypass on a vibe pump, and it does the job! By the way what everyone seems to call OPVs when in relation to these water pumps, are actually bypass valves. Most dont realise that the pumps just pump at their full rated pressure and are not actually adjustable. The pressure relief is in the bypass. In the case of vibe pumps the bypass is external to the pump body and with machines that are not plumbed, that resulting bypass goes back to the water tank reservoir. In a rotary pump the bypass is across the outlet and inlet sides of the pump ie, the water bypass goes back to the inlet side and goes back into the pump with the fresh feed. You are adjusting the outlet bypass (basically as with a vibe pump) when you turn the screw in the adjuster......not the pump pressure produced by the pump itself which as stated, remains static at its maximum rated pressure. Just one of those little points!

In the case of positive displacement pumps like the procon the pump pressure inside the casing is actually the same as the outlet pressure. They are fixed volume (not perfectly as per their pump curves) not fixed pressure and by bypassing some of this volume back to the inlet side they see a reduction in pressure at the outlet. That means that the valve is open (it always is unless producing a lower outlet pressure than set) pressure on both sides of the valve allowing for a small loss across it due to friction is the same. In the case of say pumping into a bucket with little to no restriction (very low back pressure) internal pressure in the pump housing will be still the same as the valve will be closed so very low pressure. If this PRV was to become stuck and then the pump kept running with no flow it would destroy itself internally due to very high internal pressure as I have seen happen in industry.

askthecoffeeguy

well its been an eternity of grumpy starts to the day and not enough caffeine but I finally pick up my baby tomorrow with side panels firmly attached, a clean and descale throughout, and not much else really - as it was in pretty good nic to start off with so picture should be up shortly I've held off for now on replacing the plastic side panels with some other material as I'd rather be drinking coffee than waiting on a cosmetic mod to the machine! P

askthecoffeeguy

Ok so I got to have a play with the beast tonight and the verdict? Shot quality very good 40mls from 40 seconds - but milk production very slow: 40 secs to heat 180mls of unhomogonised milk - too slow for any commercial application The wand is clean and the steam is dry and even so I'm pretty sure it's not the wand - any ideas in how to trick it up a bit? Cheers, Pat

Lacehim

different steam tip? What's the pstat set at?

askthecoffeeguy

Dunno I'll have to whip the top off and have a look I'll also experiment with different steam tips to see if I can get a better result which theoretically should be possible as my S24 has plenty of steam power and as far as I can tell they're indentiacal under the hood

FreshCoffee2

Pat.....its not really a commercial machine though is it, and we dont know if that is normal for the model. Its used.....and maybe there is a partial blockage in the steam valve assembly. Until you check that out, you cant say whether the steam delivery is impaired or not...it could be normal for the model, and all that makes playing with different steam tips quite superfluous at the moment. Hope that helps.

askthecoffeeguy

It's rated at 90 coffees per hour and indeed I've knocked out 60 in an hour on the S24 although I had to work pretty hard out to do that - Im famaliar with the specs from the S24 which I owned previously and I had the steam cranking on that machine so I'm hoping that a little tinkering will produce a similar result

FreshCoffee2

well, that leads to a partial blockage somewhere in the steam circuit, whether it be the tip or further up the line. Does the tip look like the "regular" tip you had on the other machine? ie number of holes and size of orifice.

askthecoffeeguy

Fresh Coffee wrote:

well, that leads to a partial blockage somewhere in the steam circuit, whether it be the tip or further up the line. Does the tip look like the "regular" tip you had on the other machine? ie number of holes and size of orifice.

no - new tip is four holes and different shape to old machine which was three - it appears to be original though as the shape is harmonious with the rest of the steam wand - cant seem to budge it though to get it off and even though the machine is only two years old and has only had domestic usage - there was quite a build-up of lodged coffee grinds on the shower screen - which leeds me to believe that it has not been that well maintained. A descale removed a bit of material but not much, so I think its pretty clean inside I'll try again to get the tip off and a pipe cleaner inside the steamwand - otherwise the whole assembly may need to come off to clean it up a bit cheers, pat oh and here's some long awaited photos!

askthecoffeeguy

note the bolts on the side of the machine - we had to bolt the side panels on to stop them from falling off - not particularly sturdy construction - but much lighter to lug around than the previous model!

FreshCoffee2

They're usually loktited on during assembly so the first time you try and take it off its difficult. Italian manufacturers are not that fussed on the milk side of the machine because they dont do milk (like we do)..... so its not uncommon to find them having fitted tips on small machines, that are like the ones on their big machines, where there is a lot more steam volume. ie....More holes, bigger holes (than they should have for the capacity of the smaller machine) This results in a massive steam grunt at first, that dies quickly and the machine cant recover unless you close the steam tap and give it a minute.....ie it wont recover while you keep pulling steam out. When the steam dies, and if the operator keeps going, you can eventually end up with a bit of a milk suck back that may go as far as the steam tap/valve where it dries into a grunge and does a partial or total black. Disassembly & manual clean is required. OR...nothing is blocked and the tip is simply too big for the machine causing it to die quickly. Try temporarily blocking two of the four holes with toothpicks and see what that does. Also smell the steam. The smell usually tells you if there is milk up there going off.

askthecoffeeguy

Anger Management wrote:

Pat. In most cases that I have seen where the issue is actually in the steam line has been due to; 1: Milk that has been sucked back and dried out. Usually in the tip and close to the tip in the actual steam pipe. 2: Scale in the steam valve 3: Crap in the steam valve Can say for sure as to the steam valve as different configs can change the behaviour. But steam valves are also a play that many skip and or fail to take care of and thus can be am issue. When you drop the valve spindle etc a good strong light may also you to see if the seat is OK and or if there is any scale on the inlet side; as this can and does get over looked...

Sounds about right to me - I'm happy to start with popping the steam tip off and giving it a clean from the bottom up - but the bloody tip is stuck on rock solid - any tips for getting it off!

UNM

giving the steam tip a thermal shock may help. play your blow torch on it for a few seconds (running steam through would be second best), then a glass filed with ice water to chill it quickly., in the absence of any other tools, pliers with a layer of rubber to protect the surface of the tip should then help dislodge it. rubber gloves folded over a couple of times or silicone pot holders will work. this is of course assuming it is removable and not brazed in place.