I got an assorted set of vinyl(?) stick-on furniture protectors from a hardware super store. I used the small ones in various places on the frame to isolate the outer shell. The large expanses of stainless still resonate a bit and would benefit from some application of dampening material on their inside surfaces. The biggest offended is the cup warming tray at this time. If two stacked plates are on it they rattle like crazy. Even though I have used some softer foam isolation dots it hasn't helped much. This is why I said that it would have been nice if the warmer had been attached with screws. Softer rubber mounts for the motor might also help.

tekomino wrote:Considering that all machine does is pushes hot water through coffee it is surprising it makes such a big difference

Oh I see what you did there!

Postby Aaron on Sun Dec 25, 2011 2:11 pm
I agree that it would be nicer with improved vibration damping.

Edit: Oops, I hadn't seen Randy's reply. I guess this is just reinforcement.

Aaron, I've gone through my VBM DD and put felt pads (from Lowe's) at all the metal-to-metal spots where the top and back covers touch. This has helped the noise a lot. (Randy, thanks for that tip.) In my case the reservoir holder bracket touched the pump pressure-relief adjusting screw, which made lots of noise. To fix this I just bent out the reservoir bracket, as shown here:

Since this bracket is internal, beauty is not essential. I now feel like I'm getting the claimed advantage of rotary pumps being quieter, which wasn't the case before these mods.

You might also be interested in my temperature-profile measurements, which have resulted in very flat profiles on my DD. I just posted the latest here:
Preinfusion to control temperature excursions of a rotary pump
Hope this helps.

My new Alex Duetto is also having some noise issues. It started out being quiet, but now it's developed a loud humming/buzzing noise a few seconds after the pump starts.

I removed the top of the machine and watched the pump as it runs, and it seems like the torque of the pump causes it to shift slightly on its mounts and contact the brew boiler and steam lines. Since there is very little space between the parts inside the case, even this slight shift is enough to cause metal on metal contact and annoying vibration noise.

If you look at the pictures on Chris' Coffee's website, you can get some idea of how cramped it is inside the case, and how little room there is between the pump and the brew boiler and steam lines.

http://www.chriscoffee.com/products/home/espresso/izzoduetto

I tried to push the pump back away from the bew boiler, which helped a bit, but the noise still comes back after the pump runs for a few seconds.

I'm wondering if it would be a good idea to use a cable tie to hold the pump back away from the brew boiler area. Maybe wrap the tie around the pump and part of the frame so that it can't move as much. I'm not sure if there's a way to do this effectively though since there doesn't seem to be any place on the frame to attach the cable tie so it holds the pump away from the front of the machine.

I also had the idea of putting some kind of soft rubber between the brew boiler and the pump to kill the vibration, like a piece of heat resistant silicone. I'm not sure if this would help much though, or whether it might just create more problems.

Anyone have any suggestions?

I wonder if you can find/ use thick felt pads like the type that are used for saxophone keystops. A drop of adhesive would hold them perfectly.

Beezer wrote:If you look at the pictures on Chris' Coffee's website, you can get some idea of how cramped it is inside the case, and how little room there is between the pump and the brew boiler and steam lines.

Looking at this image from CC:
http://www.chriscoffee.com/images/1896/...iewNew.jpg
It appears that there might be a mm or two to allow the motor/pump assembly to be moved towards the rear of the machine. If so, you could elongate the mounting holes on the bottom with a file or rotary tool.
But if it is under warranty, I would contract Chris first.

The DD, to some extent, is the same. Smaller cabinets and more equipment in them means less room to work, more difficult repairs, and with components close together there is more chance of component vibrations (with few solutions) and less air circulation for electronics. Oh, but the coffee! Yummmmy.

What about furniture felt pads that have a sticky backing? I use these under the rear feet of my espresso machine to make refilling the tank easier. I just lift the front of the machine and slide it forward. It's hard to plumb when renting :/

Thanks for the replies.

I just got an email back from Chris' tech, suggesting loosening the screws that hold the pump and shifting it back a bit. He also said that I can use some insulation material to absorb the vibration, as long as it won't break down from the heat. Makes sense to me. I'll try moving the pump first I guess, even though it's a bit of a pain to get at the bottom because the machine is so heavy.

Felt pads might work, though I wonder if they'd hold up to the heat near the boiler. I suspect the adhesive would melt, at least. I'd like to use something that can stand the heat in that area.

Beezer,
The felt pads go where the stainless case meets the frame. It doesn't get very hot there.

I don't understand why moving the pump "back" would reduce vibration, but please let us know if it works. Is it vibrating against the outer case?

No, it's not touching the case. As far as I can tell it's vibrating against the brew boiler and steam lines, which are only a few millimeters in front of the pump. The pump is shifting slightly when it's on, and that's enough to allow it to touch the boiler or steam tube and cause vibration. So putting felt pads probably wouldn't work, as they'd have to withstand 200 + degree temps. I was thinking something like silicon pads glued on with contact cement might work if moving the pump backwards doesn't do the trick.