Mini II group pressure adjustment

[Dodger1]

I adjusted my group pressure to ~ 8 bars but in the process I put a pretty good crimp on the bottom plastic (or whatever it's made of) tubing; please refer to the photo.

I tried to remove that tubing and reinstall it but it just won't come off. Before I muck around and break something. with my size 14 fingers, has anyone figured out how to reposition the tubing to remove that crimp.

[MDL]

I don't have a mini, but that looks to me like a piece of plastic tube on the outlet of the over pressure valve (OPV). In the VII the OPV just drips into the drip tray so a bit of a crimp would not make a big deal. On the other hand, the VII doesn't come with a tube on the end so I don't really know how things work in the mini. Adjusting the OPV is not setting the group pressure in the VII; the pump in the VII sets the group pressure. Again, I don't know how the mini handles the group pressure adjustment.

Good luck,
Mark

[Dodger1]

Thanks Mark but it's not the OPV, it's a view of the group pressure adjustment taken from the rear, as covered in the thread below.

http://www.s1cafe.com/viewtopic.php?f=3 ... ent#p11604

[Endo]

This is the bypass water outlet line from the OPV. When the pressure goes above the set point (usually 9 bar), the excess water goes back to the pump. Blocking it could oveload the pump or spring a leak. Best to remove the kink.

I'd try heating it gently with a heat gun and see it you can twist it back. If this doesn't work, you could try cutting it short and reattaching. If this still doesn't work, call Chris Coffee and order a new line

[JohnB]

I'd say Endo has the right idea, use a hair dryer or heat gun & just twist it back so you lose the kink.

[Dodger1]

Thanks for the tip Endo, it worked like a charm BTW, it's nice to see you back and posting.

Hey John, when you want to get rid of that Speedster and come back to your first love, let me know because I need a "backup machine" for my Mini II

Seriously, thanks a lot and I hope you two deadbeats made out like bandits this
Christmas.

Keith

[oton]

I adjusted my group pressure to ~ 8 bars

Mmm, should I adjust mine to 8 bar too? Or at least low the pressure a little? Mine fluctuates between 9.0 - 9.2 (Vibrating Pump). I always have early blonding in most shots, which is something that always puzzled me, specially when I watch some E61/Saturate groups extraction videos on youtube.

[Dodger1]

Try taking it down to ~ 8.5 and see if you like the results. If you do, try taking it down to 8 and reevaluate.

FYI, as you can see in my picture I ended up removing the back panel to adjust it, which was somewhat of a PIA, but it was the easiest way for me to get to the valve.

[Endo]

I adjusted my group pressure to ~ 8 bars

Mmm, should I adjust mine to 8 bar too? Or at least low the pressure a little? Mine fluctuates between 9.0 - 9.2 (Vibrating Pump). I always have early blonding in most shots, which is something that always puzzled me, specially when I watch some E61/Saturate groups extraction videos on youtube.

I use 9 bar. I had adjusted it to 8 bar for a while, but I couldn't see much difference so it's now back at 9 bar.

If you are getting early blonding, have a look at my "close-up extraction" YouTube video and tell me if this appears OK. I find most "early blonding" experiences I've had are simply caused by either coffee older than 3 weeks from roast or simply not grinding fine enough.

If you are sure you're coffee is fresh, then try this exercise: grind fine enough for a SLOW 45 seecond shot, then lighten up your nutation and tamp enough to speed it up to 30 to 35 seconds. See if this doesn't change things.

[oton]

Try taking it down to ~ 8.5 and see if you like the results. If you do, try taking it down to 8 and reevaluate.

FYI, as you can see in my picture I ended up removing the back panel to adjust it, which was somewhat of a PIA, but it was the easiest way for me to get to the valve.

Could you tell me (us) what differences did you find between 9bar and 8.5/8 bar? Taste? Channeling? Blonding? Thanks.

[Dodger1]

I found that my espresso simply tasted better at 8 bars. As to early blonding, reducing your pressure may well help but I did a quick search and ran across the following; which you might find helpful.

viewtopic.php?f=13&t=1036&p=12349&hilit ... ing#p12349

http://www.home-barista.com/tips/extrac ... ly#p130239

http://www.home-barista.com/tips/elektr ... ly#p123045

http://www.home-barista.com/tips/early- ... rly#p74555

http://www.home-barista.com/knockbox/es ... rly#p51439