...split from JetSteam Espresso Machine by moderator...

Ken Fox wrote: On the vibe, there is simply too much vibration and the ramekin has a tendency to dance across the drip tray during the shot

OK, I know I set the standard when it comes to espresso pump snobbery...but this post of yours, Ken, just cracks me up.

Shoutout to vibe pump machine users: why do you let the manufacturers get away with crap like this? You obsess about the aesthetics of your machines, you pimp and polish your chrome-plated mirror-finish groups, you wrap the grinder in a towel so as not to wake up the wife at 6am...then you turn on the pump. It sounds like a sadistic dentist performing a root canal with a jackhammer!

Is it really that hard to design a vibe pump system with some sound deadening? Chris Nachtrieb, Terry Z, are you listening?

AndyS wrote:OK, I know I set the standard when it comes to espresso pump snobbery...but this post of yours, Ken, just cracks me up.

Shoutout to vibe pump machine users: why do you let the manufacturers get away with crap like this? You obsess about the aesthetics of your machines, you pimp and polish your chrome-plated mirror-finish groups, you wrap the grinder in a towel so as not to wake up the wife at 6am...then you turn on the pump. It sounds like a sadistic dentist performing a root canal with a jackhammer!

Is it really that hard to design a vibe pump system with some sound deadening? Chris Nachtrieb, Terry Z, are you listening?

My vibe pump machine has been so heavily modified that I'm not sure I can even blame Cimbali on this. At the moment, there is a knockoff braided hose twice as long as from the factory, which goes out of the vibe pump into the rest of the plumbing, which itself has been modified. The OPV, which does not really function in the stock configuration, has been adjusted to work and has a silicone tube taking the excess water back to the pourover tank. All of the moving parts were replaced last year, and in the process the machine developed many leaks in the old copper fittings, which I tediously got rid of. The orientation of various pieces of copper is not exactly as it was before, but it works well.

I have done a few things to try to mitigate the noise and vibration, but nothing major, such as putting a rubber hose over the braided SS hose coming out of the pump. The reason why I have left everything in its current condition is that the changes unintentionally further damped out the pressure ramp up, as measured by a PF manometer. It takes a full 7 seconds to get up to 9 bar, and does it very very gradually, more than it did before. I consider this a plus, an accidental improvement, and am willing to put up with whatever occasional additional noise it produces. Considering that the machine operates maybe 1 week per month, and makes maybe 3-4 shots per day when it is working, the situation is not very distressing to me.

ken

HB wrote:My electric razor makes about the same noise as a vibe pump running;

I have previously suggested to you to get rid of that old Remington and try out a Norelco.

ken

Just a thought...If the vibe pump depends upon the reaction of the innerd's along the axis of the outer part, the more firmly the pump is mounted, the better the performance and volume as there is no end to end vibration of the housing allowed to reduce the strength of each stroke of the piston. Perhaps adding a heavy mass to the pump and mounting the whole in rubber mounts would be a help. Keep it cool though!
http://jeromeetisabelle.free.fr/articles.php?lng=fr&pg=36
So, if so, I would think that any reduction of the radial and elongation stiffness of the plumbing from it would allow the pump to ramp up more slowly. Or, for instance; a Basket ball is very easy to pump till the last few strokes which take it to full pressure.
1¢
richard

Has anyone ever measured the frequency of the vibe pumps? My guess is that its around 15-20Hz, but I will see if I can test that tomorrow. After finding the frequency of it, it would be fairly simple to design an isolation system. Practicality would depend on the physical size and empty space inside the machine. A rubber mount could be effective, but for total isolation (of the pump at least) it seems like some sort of cradle of springs would be needed.

Just thinking out loud here, unless someone else has already done this, I'll post my results if I can get any tomorrow in a new thread.

espressme wrote:Just a thought...If the vibe pump depends upon the reaction of the innerd's along the axis of the outer part, the more firmly the pump is mounted, the better the performance and volume

I don't understand; the "performance" and volume of the pump is already more than enough.

gtrman wrote:Has anyone ever measured the frequency of the vibe pumps?

Depends on where you are. In N. America, 60 hz.

That would be the frequency of the electricity right? Is it also the frequency of the piston in the pump?

gtrman wrote:That would be the frequency of the electricity right? Is it also the frequency of the piston in the pump?

Yes. The pump uses a diode to produce pulsing DC. This DC repeatedly fires a piston against the resistance of a return spring.

I must confess that this info has been told to me by others; I have never dissected a vibe pump to verify it personally.

Someone who has, please chime in.