mohninme wrote:Its really user dependant. Some likely start with the valve fully closed and then consider the start of the shot when they crack the valve rather than when they open the brew lever. Everything after that will be adjusting to your grind level, roast level, target brew pressure, yield etc.

You can expect a softer or even sloppy puck with finer grinding and longer PI.

The Bianca paddle on a vibe pump actually allows the user to stop the built-in preinfusion that occurs with vibration pump espresso machines. In other words, the vibration pump typically takes 7-9 seconds to get the pump at full pressure... hence a pre-infusion. With the paddle in the full closed position for 9 seconds, the pump can ramp up to the pressure of the OPV, thus taking away from the pre-infusion.

Hi Jim,

That's very interesting, after that 9-second cut-off, we push the paddle to full open position, how long does it take to see a full level pressure in the group head gauge? Does it still take a bit time for the viber to build up the pressure in the coffee puck? Thanks.

EthanL wrote:That's very interesting, after that 9-second cut-off, we push the paddle to full open position, how long does it take to see a full level pressure in the group head gauge? Does it still take a bit time for the viber to build up the pressure in the coffee puck? Thanks.

I can speak to this. If you already have the group head filled with say 2 bar PI on the puck then the pressure build is almost instantaneous when you open the paddle. If you are starting with an empty group you can expect a few seconds delay to build full pressure as it fills the cam chamber and head space.

I have not read the whole thread so forgive me if I repeat.

I installed the paddle kit on a Lelit Mara. I didn't change the restrictor(or gicleur). When the paddle is fully to the left, it shuts off the flow completely. The problem is when the paddle is fully to the right, the flow rate is only ~1.6ml/sec. Is that normal? If not, will change the restrictor help? Because the flow rate is so slow, it takes a long time and there is really no need to move the paddle.

I have a Lelit Bianca that comes with a paddle. When fully opened, the flow rate is ~6.4ml/sec, about 4 times faster.

Thanks in advance,

Yes, you need to change the restrictor. The restrictor and the needle are designed to be a matched pair. As you've noticed, smaller restrictors greatly increase the precision of the valve at the expense of sensitivity. Conversely, larger restrictors offer much better "throttle response" at the expense of precision.

I think Lelit did a nice job striking a balance between sensitivity and precision with their design. Use their restrictor and you will like the results.

Cheers!

- Jake

Thanks for the reply. Will do.

The reason I didn't change the restrictor was I didn't have the haxagon wrench and it looks the same between the existing and new one.

robertw wrote:I installed the paddle kit on a Lelit Mara. I didn't change the restrictor(or gicleur)

I have a Mara and have the have the Lelit kit installed. The stock gicleur orifice size on my Mara was way too small to accept the tip of the profiling valve assy. I hope you haven't damaged your valve. What model is your Mara?

mohninme wrote:I have a Mara and have the have the Lelit kit installed. The stock gicleur orifice size on my Mara was way too small to accept the tip of the profiling valve assy. I hope you haven't damaged your valve. What model is your Mara?

<image>

It is the cheapest one. Should have come to this forum earlier....

Jake_G wrote:...I think Lelit did a nice job striking a balance between sensitivity and precision with their design. Use their restrictor and you will like the results.

Cheers!

- Jake

Jake, you nailed it!

Two years of development, testing, more testing, more refinement, more testing... to get that perfect balance. Although some will want more flow, I believe the HOLY GRAIL was found within a certain range of flow.

I confirm, the gicleur in the mushroom MUST be changed.