Breville Dual Boiler "Slayer shots"? - Page 50
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blazarov
- Posts: 28
- Joined: 5 years ago
Hi again,
I have implemented the Mod on my Silvia as described above, using the "Jake" Clippard valve.
It is my first day and still testing. Apparently it is working somehow, but so far i find it quite inconsistent in the low flow rates (anything less than 2ml/s)
The flow seems to completely stop (dry out) while the pump is still running and it start again 10 seconds later. At this point almost no backflow from any of the 2 OPVs which is rather surprising. I have no easy way to measure the pre-NV OPV to set it to something meaningful.
Clip: http://www.youtube.com/watch?v=u9qcz9z4GYk
This time there is backflow from the pre-NV OPV because i have lowered its setting just to see if it will help but it doesnt. I have tested the entire range of the pre-NV OPV, but this effect of uneven flow at low rates remains.
So far havent changed the post-NV OPV because i dont see the point - all my tests are with no portafilter and it never sees any pressure at all.
BDB also has 2 OPVs like in my setup, right? 1 pre- and 1 post- needle valve?
I am wondering what would be a good idea for their pressure settings..?
In your BDBs do you see the flow nice and steady even at the low rates?
Thanks!
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blazarov
- Posts: 28
- Joined: 5 years ago
Sorry for posting after myself, but i just got the Eureka! moment after watching my own video.
The hissing sound was pointing the obvious cause for my troubles - with so slow flow the water was overheating and thus boiling.
As expected the PID needs serious tuning to be adequate in such extremely low flow rates.
Temporarily i set the PID to 70C and the proactive factor (power offset during pump active) to 0 and voila flow is nice and smooth and so far tests show pretty consistent.
Will keep in touch.
Now i am happy
thanks to all of you for sharing the knowledge and experience!
The hissing sound was pointing the obvious cause for my troubles - with so slow flow the water was overheating and thus boiling.
As expected the PID needs serious tuning to be adequate in such extremely low flow rates.
Temporarily i set the PID to 70C and the proactive factor (power offset during pump active) to 0 and voila flow is nice and smooth and so far tests show pretty consistent.
Will keep in touch.
Now i am happy
thanks to all of you for sharing the knowledge and experience!-
pcrussell50 (original poster)
- Posts: 4030
- Joined: 15 years ago
The BDB only has one OPV on the brew system (there is another one on the steam system because the BDB has a separate dedicated pump for filling the steam boiler). The needle valve in the BDB is just before the solenoid. Flow is perfectly steady and can be secondarily read by reading the pressure gauge, which shows group pressure. This pressure gauge is very nice though not absolutely necessary.blazarov wrote:
BDB also has 2 OPVs like in my setup, right? 1 pre- and 1 post- needle valve?
I am wondering what would be a good idea for their pressure settings..?
In your BDBs do you see the flow nice and steady even at the low rates?
Thanks!
Is there any way you can put your needle valve after everything, but just before the solenoid? Good job by the way. You may have the best Silvia on the planet if you get this worked out.
-Peter
LMWDP #553
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blazarov
- Posts: 28
- Joined: 5 years ago
Hi,
I agree that ideally NV should be after boiler, but in Silvia that would need very precise custom machining. Almost to a point where actually purchasing a Slayer is more likely for me than successfully implementing the mod
For this reason i was unsure about the success of my mod, but actually when them temp is low it works beautifully - flow is perfectly steady and consistent.
Unfortunately so far anything close to actual brew temp flows like in the clip.
So now i am trying to find emperically what is the temperature threshold.
Btw BDB owners do you need to tune PID or at least change brew temp for slow shots?
I agree that ideally NV should be after boiler, but in Silvia that would need very precise custom machining. Almost to a point where actually purchasing a Slayer is more likely for me than successfully implementing the mod
For this reason i was unsure about the success of my mod, but actually when them temp is low it works beautifully - flow is perfectly steady and consistent.
Unfortunately so far anything close to actual brew temp flows like in the clip.
So now i am trying to find emperically what is the temperature threshold.
Btw BDB owners do you need to tune PID or at least change brew temp for slow shots?
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myso
- Posts: 187
- Joined: 5 years ago
Hi,
BDB and Silvia are quite different in design. Silvia pumps cold water to the boiler whereas BDB pumps preheated water (thru HX in steam boiler similar to LM GS3). Thus water entering the brew boiler is higher in temperature maybe even near brew temperatures. Also BDB benefits from heating element inside the brew head. So it is intrinsically less prone to temperature fluctuations.
I can suggest the recent thread where pid settings overshoots temperatures during shots. Or you can check the alarm output option during shots (during shot heat elements are running partially to prevent temperature drop)
Gaggia Classic 2019 - REX C100 PID
https://www.coffeegeek.com/forums/espre ... 1567812782
BTW when you first mentioned I thought it maybe air stuck inside boiler but evaporated water also explains since it's also compressible. I was going to suggest "priming the boiler manually" by letting water flow out of the steam wand then closing steam valve to have flush from brew head.
BDB has a tube from boiler to grouphead so it's a bit easier to make sure to control only the hydraulic path.
BDB and Silvia are quite different in design. Silvia pumps cold water to the boiler whereas BDB pumps preheated water (thru HX in steam boiler similar to LM GS3). Thus water entering the brew boiler is higher in temperature maybe even near brew temperatures. Also BDB benefits from heating element inside the brew head. So it is intrinsically less prone to temperature fluctuations.
I can suggest the recent thread where pid settings overshoots temperatures during shots. Or you can check the alarm output option during shots (during shot heat elements are running partially to prevent temperature drop)
Gaggia Classic 2019 - REX C100 PID
https://www.coffeegeek.com/forums/espre ... 1567812782
BTW when you first mentioned I thought it maybe air stuck inside boiler but evaporated water also explains since it's also compressible. I was going to suggest "priming the boiler manually" by letting water flow out of the steam wand then closing steam valve to have flush from brew head.
BDB has a tube from boiler to grouphead so it's a bit easier to make sure to control only the hydraulic path.
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blazarov
- Posts: 28
- Joined: 5 years ago
Hi,
I have reconfigured the PID so it does not turn on the heating element at all during the entire shot time. Nevertheless water still seems to be boiling at low flow rates at otherwise completely normal brew temps.
I was also thinking of some sort of air pockets due to the throttled boiler inlet, but this effect is completely gone at say 80C.
I have reconfigured the PID so it does not turn on the heating element at all during the entire shot time. Nevertheless water still seems to be boiling at low flow rates at otherwise completely normal brew temps.
I was also thinking of some sort of air pockets due to the throttled boiler inlet, but this effect is completely gone at say 80C.
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pcrussell50 (original poster)
- Posts: 4030
- Joined: 15 years ago
So my La Marzocco subscription coffee this month had a recipe for a "ristretto". The recipe calls for a 18in/25out 6 bar pull for 50'ish seconds or so. Perfect for a machine with the capability. Little awkward doing the needle valve while trying to film interesting camera angles:
The pressure needle movement early on is me fiddling the needle valve knob back and forth while holding the camera with the other hand.
Ground at 2.8 on Monolith FlatSSP. A little acidic but how I like it. If you wanted, you could mute the acid a little by grinding finer and doing a slow drip pre infusion for 15s (or as long as it takes to get the acid level where you want it). This is the beauty of this mod.
-Peter
The pressure needle movement early on is me fiddling the needle valve knob back and forth while holding the camera with the other hand.
Ground at 2.8 on Monolith FlatSSP. A little acidic but how I like it. If you wanted, you could mute the acid a little by grinding finer and doing a slow drip pre infusion for 15s (or as long as it takes to get the acid level where you want it). This is the beauty of this mod.
-Peter
LMWDP #553
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pcrussell50 (original poster)
- Posts: 4030
- Joined: 15 years ago
It occurs to me from the general message traffic over the past few months, that perhaps a brief synopsis of what we're talking about here is in order...
What is meant by a Slayer shot?
Slayer is the granddaddy of the flow profiling (flow control) movement. It offers essentially two "speeds" or flows. Low and high. Pre Brew and Brew in the Slayer vernacular. You start one paddle click left, in low, in which the pump runs at full power, but flow is at a greatly reduced rate, set by a needle valve you pre set inside the machine. Slayer calls this mode, "Pre Brew". The rest of us might refer to it as pre infusion. When you are done with it, you move the paddle one more click left, and the flow bypasses the needle valve and runs as usual just like any other espresso machine. You can finish your shot by going back one click right, to the pre brew/pre infusion position where you started your shot, or go full right and shut it off altogether. This is similar to using the BDB pre infusion in manual mode. Slayers used for todays super light roasts might pre brew for 30s before first drops begin to appear.
A stock BDB has almost the same thing:
If you press and hold the manual button, the BDB stays in pre infusion until you release it, then it goes into regular brew. You can set the pre infusion flow/pump output in the pre infusion menu. I think the lowest you can go is PP55. If you want to taper the flow towards the end, you can crack open the water knob. If you want to crack open the water valve a long way, you will have to move the microswitch off of the knob and you can open it as much as you like to taper off the flow. Differences with Slayer: With Slayer, you can set your pre brew/pre infusion flow as low as you want. Most people settle on something around 1.5ml/s. The BDB at PP55 will be around 2-2.5ml/s. Full flow with Slayer or BDB will be about 7ml/s. This will offer a HUGE amount of the benefit of a Slayer, although at the highest levels, some people will still want pre brew flow of 1.5ml/s, where the stock BDB can't quite go that low. If I had my guess, I'd bet most people couldn't begin to tell the difference.
But you can still do more with the BDB. A LOT more in fact. More than a stock Slayer:
You can do what we call the "Slayer mod", even though at the end of the day, it actually gives more than an actual Slayer. This is the nut of this thread, and post #1 Breville Dual Boiler "Slayer shots"? of this thread contains a link that takes you to the point in this 50 page behemoth where the process is described. In a nutshell, I don't even want to call it a mod, because you are not adding anything or cutting or drilling or fabricating. All you are doing is swapping the outlets of two existing water tubes and capping off a third. This takes the hot water dispensing out, and you use the hot water valve knob to control flow on the fly, from the super low flow pre infusion, as low as you like, all the way to full flow and anywhere in between. It is this last thing that Slayer can't do. Slayer is high or low only. It cannot go anywhere in between like you can with this mod. In reality, what this is most like is the Bianca, sticking with commonly available machines.
Hope this summary is found useful to newcomers and fence sitters alike.
-Peter
What is meant by a Slayer shot?
Slayer is the granddaddy of the flow profiling (flow control) movement. It offers essentially two "speeds" or flows. Low and high. Pre Brew and Brew in the Slayer vernacular. You start one paddle click left, in low, in which the pump runs at full power, but flow is at a greatly reduced rate, set by a needle valve you pre set inside the machine. Slayer calls this mode, "Pre Brew". The rest of us might refer to it as pre infusion. When you are done with it, you move the paddle one more click left, and the flow bypasses the needle valve and runs as usual just like any other espresso machine. You can finish your shot by going back one click right, to the pre brew/pre infusion position where you started your shot, or go full right and shut it off altogether. This is similar to using the BDB pre infusion in manual mode. Slayers used for todays super light roasts might pre brew for 30s before first drops begin to appear.
A stock BDB has almost the same thing:
If you press and hold the manual button, the BDB stays in pre infusion until you release it, then it goes into regular brew. You can set the pre infusion flow/pump output in the pre infusion menu. I think the lowest you can go is PP55. If you want to taper the flow towards the end, you can crack open the water knob. If you want to crack open the water valve a long way, you will have to move the microswitch off of the knob and you can open it as much as you like to taper off the flow. Differences with Slayer: With Slayer, you can set your pre brew/pre infusion flow as low as you want. Most people settle on something around 1.5ml/s. The BDB at PP55 will be around 2-2.5ml/s. Full flow with Slayer or BDB will be about 7ml/s. This will offer a HUGE amount of the benefit of a Slayer, although at the highest levels, some people will still want pre brew flow of 1.5ml/s, where the stock BDB can't quite go that low. If I had my guess, I'd bet most people couldn't begin to tell the difference.
But you can still do more with the BDB. A LOT more in fact. More than a stock Slayer:
You can do what we call the "Slayer mod", even though at the end of the day, it actually gives more than an actual Slayer. This is the nut of this thread, and post #1 Breville Dual Boiler "Slayer shots"? of this thread contains a link that takes you to the point in this 50 page behemoth where the process is described. In a nutshell, I don't even want to call it a mod, because you are not adding anything or cutting or drilling or fabricating. All you are doing is swapping the outlets of two existing water tubes and capping off a third. This takes the hot water dispensing out, and you use the hot water valve knob to control flow on the fly, from the super low flow pre infusion, as low as you like, all the way to full flow and anywhere in between. It is this last thing that Slayer can't do. Slayer is high or low only. It cannot go anywhere in between like you can with this mod. In reality, what this is most like is the Bianca, sticking with commonly available machines.
Hope this summary is found useful to newcomers and fence sitters alike.
-Peter
LMWDP #553
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Quester
- Posts: 593
- Joined: 8 years ago
My modded BDB is at a location I'm rarely at, but I've been pulling shots on it for the last week. I've been emulating the Londinium R profile I use on my Decent DE1. And I'm using the same beans and the identical grind settings I used on the Decent. Same VST 20g baskets.pcrussell50 wrote:All you are doing is swapping the outlets of two existing water tubes and capping off a third. This takes the hot water dispensing out, and you use the hot water valve knob to control flow on the fly, from the super low flow pre infusion, as low as you like, all the way to full flow and anywhere in between.
The shots are great. They are not the same as the Decent and I could differentiate between the Decent and the BDB--but it's super fun profiling on the Breville. And I'm getting better with the touchy stock needle valve. Practice, practice, practice.
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pcrussell50 (original poster)
- Posts: 4030
- Joined: 15 years ago
It doesn't take much, just a crack, to get a nice slow Slayer'esque 1.5ml/s pre infusion on the stock BDB needle.
On mine I took out the stock one and use the Jake needle which is a little "slower"... IOW less sensitive. It's not night and day mind but a little.Though I never thought the stock BDB needle required astronaut-level fine motor skills.
-Peter
On mine I took out the stock one and use the Jake needle which is a little "slower"... IOW less sensitive. It's not night and day mind but a little.Though I never thought the stock BDB needle required astronaut-level fine motor skills.
-Peter
LMWDP #553
