Quieting vibe pump

#1: Post by **t3steve** » December 23rd, 2014, 4:06 pm

I know there have been threads concerning this in the past.

The vibe pump noise is really bugging me and motivating me to want to replace what is otherwise a great machine
I checked and the panels are not vibrating and the water lines in and out of the pump don't seem to be vibrating against any panels.

I was thinking I could try completely encasing the pump in a noise absorbing rubber pad to reduce the noise at the source.
Has anyone tried this?
Will the pump overheat?

#2: Post by **another_jim** » December 23rd, 2014, 4:18 pm

Chances are the rubber sound damping mount is worn out and no longer doing its job. These mounts should be treated as routine replacement items, since new vibe pump machines are usually quiet and tend to get noisy after about 18 months.

#3: Post by **jonr** » December 23rd, 2014, 5:24 pm

It would be interesting to form a box around the pump and then pour it full of some type of liquid rubber (as used for molds). Given the low duty cycle, I don't think it would overheat.

#4: Post by HB » December 23rd, 2014, 7:54 pm

There's a lot of previous discussions on quieting vibratory pumps. Below is an excerpt from Rotary Pump HX Espresso Machines & Their Sounds that touches on how both vibratory and rotary pumps depend on mounts to be quiet:

dmankin wrote:My question is this; Should a properly functioning rotary pump be silent, near silent, or make a whirring sound?

HB wrote:Vibratory pumps get a bad rap because... they vibrate. If you run one free from an espresso machine's casing, it makes less noise than an electric razor. Alas vibratory pumps do indeed vibrate, producing a tinny reverberation of interior components. I'm not making this up, I "outboarded" mine and the noise level is about the same as an inboard rotary pump:

Rotary pumps by their nature produce very little vibration. If they have an ample water supply to avoid cavitating, they operate nearly silently. If they're mounted externally as is the case in the majority of cafes, you will hear nothing unless you open the cabinet and listen carefully. Most manufacturers of inboard rotary pump espresso machines mount them on squishy rubber footings, arresting the little vibration the pump produces.

I assume the whirring sound you hear is not from the pump itself, but sound produced by sympathetic vibration. Mounts that are made of too hard a rubber, not enough rubber, components touching each other, etc. can result in odd buzzing that is very difficult to locate. As a case in point, the original La Spaziale S1 rotary pump mounts were replaced by slightly softer rubber in the final production model. I retrofitted them in during the final weeks of testing and was astounded by the noise level reduction. So the answer to your question "Should a properly functioning rotary pump be silent, near silent, or make a whirring sound?" is regrettably "it depends."

http://users.rcn.com/erics/ · #5: Post by **erics** » December 23rd, 2014, 8:14 pm

For Stephen - It would be very beneficial if you post a pic of your pump and the existing mounting arrangement. And, is this the Cimbali you are having noise issues with?

#6: Post by **pizzaman383** » December 24th, 2014, 8:40 am

I've done a bunch of work on my VBM to quiet the vibe pump and it's been fairly successful. I used the standard techniques of eliminating contact of the tubes against the frame/boilers, put cushioning between parts that touch, ensuring the pump mounts were new and installed properly. I even put dynomat (sp?) on the flat surfaces like the audiofiles do to deaden vibration.

While this was helpful there is still noise. Sometimes, there's more noise than at other times. I have my machine plumbed in and recirculate the OPV output to the pump input through a check valve. I think that some of the noise is caused by the pulsing of the water column and maybe that some is caused by air trapped in the lines. I know that the check valves and OPV probably make some of the noise.

Are there any devices that can reduce the noise caused by pulsing in the water within the lines?

December 24th, 2014, 10:51 am

Wow you guys are fast on the response. I can't open it up to take pict until after Christmas. Yes I am talking about the Cimbali Jr

#8: Post by **Iskanda** » December 24th, 2014, 10:58 am

Some people consider this item: http://www.sf-ersatzteile.de/Ersatzteil ... branregler as useful for lowering the noise. I know only the german name (Membranregler) and it is used in some Quickmill-machines.

December 24th, 2014, 1:22 pm

Very cool. I may try that.

http://users.rcn.com/erics/ · #10: Post by **erics** » December 24th, 2014, 3:32 pm

Very cool. I may try that.

It may be available from Chris' Coffee as I BELIEVE it is fitted to the Quickmill QM67. You may need to send them a pic.