Your pump noise sounds fine to me. The sound will vary. It's ok.

Also, I do mine "Slayer style". I don't bother with the programmable pre infusion. I just run the pump at full power the whole time and control the flow with the needle. Slayer has only one pump speed, high, as well. Some others do use the programmable pre infusion part of the time, like you are.

Finally, re sensitivity, response will never be linear. Pressure, as distinct from flow, will always start slowly and accelerate for a given needle position. And as the puck erodes, flow will increase for a given pressure. Life in flow profiling.

Welcome.

-Peter

rosslyn568 wrote:Also, out of curiosity, what do you have your OPV set to?

Hi Chris,

Not sure I saw this question answered for you...mine, and many others are set to 9 bars. That's sort of "industry" standard, however, I know a few people that like their OPV set to 10 bars, while others like 7 to 8 bars.

10.5 bars with a blind insert results in 9 bars at the puck for me.

I did not touch mine. After preinfusiom it is almost always dead on at 9 bars. Sometimes it fluctuates a little between 8.5 and 10.

Just finished the mod on my BDB. First shot pulled was an Ethiopia Bensa Shantawene. I was just guessing at the pressure profile and ended up with a sweeter shot than the traditional 9 bar shot I was pulling this morning. Maybe I got lucky. But it's pretty exciting.

I had no trouble routing the line to the water nozzle-the coat hanger worked first try. All the plumbing took under five minutes.

The only issue I had was sealing the water nozzle. I cut a circle out from a food grade collapsable water cup, but it leaked the first time. I simply added more circles and pushed them down to create a slight bit of pressure. It sealed after I did this.

What a great idea you guys! Now I'm noodling how to mod my GS3 . . . .

Welcome to the world of profiling.

Quester wrote: What a great idea you guys! Now I'm noodling how to mod my GS3 . . . .

Boy, if that isn't the question of the year! Ever since I got my first BDB when they first came out in fall of 2011, I always told myself I'd just see what this dalliance was all about, then I'd cut to the chase and get a GS/3... And, yet... over the years, this little dalliance was able to keep up with all the hottest extraction techniques, while also proving quite reliable to boot... It just has never (yet) given me good reason to leave. It's the darndest thing.

As to flow profiling the GS/3, it seems like your best/easiest route would be to rock it old skool and go the "Slayer" route. By this I mean, instead of having the whole shot under our direct control from start to finish through the needle valve like you do now with your BDB, you would plumb in a second path, one for high/normal flow, and one for low/pre infusion flow. This second path will have a needle valve that you pre set before the shot, but have no direct, on-the-fly control over. If you don't like where it's set, adjust it up or down before your next shot, and repeat until it's to your liking. You start your extraction in low flow, then switch to high for the main part, then back to low, to finish. Having only two discrete flows sounds crude in comparison to what we have now, but I and some others suspect that while it's crude, it still captures a lot of the benefit of full control all the time, even if it's not quite as capable. Look up HB'er Shawndo. I think he did this on his LM Shot Brewer (GS/3 without steam). Otherwise you are looking a Assaf's "Chimera" gear pump with Arduino custom controller or Pepperssas Dick Green's similar. These sound immensely capable, though they are using gear pumps on a custom controller for precise flow control. Might be a considerably bigger job than taking the "Slayer approach".

-Peter

Very much this ^^^

If you think you can abide a situation where you can plumb a valve outside the machine, with a direct knob right on it, you should be able to do it this way. If you have the MP, you would be using the paddle strictly for on-off.

-Peter