ash4889 wrote:Would love to see a video of the work you've done?

In the video, the water's flowing through a shot simulator that approximates the flow rate of an espresso shot. I run a shot through this to stabilize the temperature and pressure of the machine so I don't need to sink the first shot.

The machines in the video are:
1. Vibiemme DoubleDomo v2 with Fluid-O-Tech vibe pump direct plumbed.
2. KitchenAid Pro with Eaton vibe pump
3. Fiorenzato Doge 83 with Mazzer Major burrs - single dosing on espresso setting
4. KithchenAid grinder with Mazzer Mini burrs - drip setting

https://www.youtube.com/watch?v=DeUs41WyEf0

bas wrote: I have just replaced the Ulka EX5 pump by an EX4 pump with a Quickmill Pulsor on my QM Silvano.
(...)
And maximum pressure is reached after 10 seconds in stead of 5 seconds.
Kind of active preinfusion.

pizzaman383 wrote: (...)
The Ulka with a quickmill pulser (available from Chris Coffee) or the fluid-o-tech does seem a little quieter.

Thank you Bas and Curtis for sharing your mods. I am interested in experimenting with a slower pressure ramp for my Quick Mill Silvano, and it sounds like the Ulka EX4 + Quick Mill Pulser may help me achieve that -- with the bonus of a quieter machine as well. Could you please help me with a few questions ?

1) I've checked the Chris Coffee website but could not find the Quick Mill Pulser. Is that something which requires a special order ?
2) In a few words, what does a Pulser do ?
3) Would you say the slower pressure ramp is mostly a result of replacing the EX5 with the EX4, of adding the Quick Mill Pulser, or the combination of both ?

Thanks in advance.

Fernando

Here's a picture of the pulsor that quickmill uses. If you call Chris Coffee they will sell it to you.

It's got a membrane inside that damps the pulses from the vibratory pump. This is the only one I've seen with threads that will fit standard fittings.

Thanks a lot for the picture and explanation Curtis.

Based on my limited understanding of the two mentioned parts, it sounds like the pulsor would mostly contribute for reducing the pump noise, while the EX4 might be responsible for the slower pressure ramp (which is actually what I'm after). Hopefully Bas will chime in with his comments as well.

Thanks again !

pizzaman383 wrote:It's got a membrane inside that damps the pulses from the vibratory pump. This is the only one I've seen with threads that will fit standard fittings.

Hadn't heard of this before - interesting.

pizzaman383 wrote:The Ulka with a quickmill pulser (available from Chris Coffee) or the fluid-o-tech does seem a little quieter.

Sounds like it's effect is marginal. What's your opinion of it as an add-on? Worth doing?

I may be blind or stupid or both but that Quick Mill part just looks like a brass bushing. I fail to see how that reduces noise (vibration). Can somebody enlighten me?

earlgrey_44 wrote:Sounds like it's effect is marginal. What's your opinion of it as an add-on? Worth doing?

I don't have it installed in my Vibiemme. My brother has one installed in his Gaggia Classic and it made a big difference.

3) Would you say the slower pressure ramp is mostly a result of replacing the EX5 with the EX4, of adding the Quick Mill Pulser, or the combination of both ?

Yes the pulsor only reduces vibrations and resonance quite a lot. It does make a notable difference soundwise without a doubt.

The EX4 has a much slower pressure build up compared to the EX5. I reach max pressure around 10 bar on my Silvano now after about 10 seconds. Before with the EX5 after only 4 sec.

So I consider the slower pressure ramping as a kind of passive preinfusion. Machines like the Silvano could benefit from it as they do not have a build in preinfusion chamber like E61 machines.

For a picture of the EX4 with pulsor on my machine check my recent topic on the Dutch coffee forum:

http://koffiepraat.nl/forum/viewtopic.php?f=12&t=6355

EX4 plus pulsor is really a nice combination and a pretty cheap mod. My Silvano runs as quiet as many rotary machines I know. There is enough room in the Silvano case for teh EX4 plus pulsor, but the bottom of the frame is not that easy to reach. Crowdy in there. You have to remove the aerator/bypass that is connected to the EX5 pump. Otherwise it does not work. The two parts don't work together and there is not enough room.

Good luck.

Bas

I finally got around to installing the pulser in my Vibieme DD. It's installed right at the pump output. Here's a video with before and after sound. It's definitely quieter with the pulser installed.

https://www.youtube.com/watch?v=3tym1_Z4dkc

Thanks for taking the time (and thought) to do this. It is a very nice video.

The o-rings that can be (should be) used to seal the fittings to the Ulka pump and the pulsation dampening device are as below:

OR 2025 (Italian designation)
AS-568 size: -010
McMaster-Carr P/N P/N 9396K15
Material = Silicone