This topic has been discussed extensively on other websites (gs3cafe.com and CG) and only tangentially here on HB. This thread on gs3.com has the best illustrations and instructions on dealing with the problem http://www.gs3cafe.com/viewtopic.php?f=11&t=12, however I found a different solution that I'm posting here that might be of use to some readers. I have NOT posted this in the general GS3 thread because it is potentially a very annoying problem whose discussion I don't want to get lost in that general, backslapping, self-congratulatory thread

To distill this problem down to its essence, there were a large number of these machines that sat in a warehouse in Seattle for more than a year after they were built, and many of these machines have been sold recently under the "fire sale" at reduced prices. I got one of those, which was built 14 months before I received it recently. Noise and vibration problems on GS3s have been widely reported, and appear to be even more common in the machines that have been shipped out recently. This post gives a suggestion for work that you might do on your machine if you have noise and vibration problems. At the bottom of the post is a disclaimer in bold type; please read this before acting on any suggestions you see in this post.

There are 3 motor mounts on the pump motor, two of which have been implicated as having been overtightened (the two on the left side, shown in a picture on the gs3cafe thread). The mounts use a piece of rubber to dampen the vibrations and if the nuts are overly tight, the rubber does not dampen the vibration. Instructions from LM have been to reduce the tightening on these nuts and to spray silicone spray around them. The image below was stolen off of the gs3cafe thread, with the yellow arrows indicating the positions of the motor mount nuts:



I did this above procedure which seemed to help a little bit however after a few days the noise and vibration returned and in fact got much worse. It sounded like they were using jackhammers on the street in front of my house each time I pulled a shot, it was that bad!

I tried several times to get ahold of someone at LM recently however this time around I was unsuccessful for days and finally decided to find my own solution. Examination of the machine in operation with the left side panel removed showed that without question the vibration was coming from the outflow braided water line, which goes from the left side of the rotary pump as you face it and clearly visible on the above picture. This line, if too taut, transfers all the vibration from the pump and motor to the chassis via the brew boiler.

Here is how I solved this problem****: with the cup tray removed (it is friction fit and removes easily), use a long screwdriver (either Philips or blade shape) and loosen up the screw holding the clamp between the pump and the motor. There is a hole in the top case that will easily admit your long handled screwdriver that will reach this screw. Once loosened a bit, you can rotate the pump on the motor so that the braided water outflow line is no longer so tight that it is held tightly on the front of the brew boiler. If the braided line is too taut on the brew boiler, you will presumably need to rotate the pump in the clockwise direction. You need to be sure that you have not put the rotary pump in a position where it contacts other things such as copper water lines or the case. Once you get the pump rotated so the water line is no longer tight on the front of the boiler, and that the pump itself is not in contact with other internal components, retighten the screw on the motor/pump clamp.

In my case this completely eliminated the vibration and noise problems other than for a little bit of vibration on the drip tray, which I'm going to solve with another suggestion made in a CG thread. That was to buy a small amount of a self-sticking material called "Dynamat" (available on ebay as 2 square feet for $13 delivered) to put at contact points between the driptray and the machine's frame. Doing this should eliminate any remaining noise and vibration in this machine.

Ken

****Please note: The above suggestion requires working inside of a GS3. DO NOT do any such work on an espresso machine with the machine turned on and plugged into an electrical outlet. YOU MUST turn off your machine and unplug it from the wall before attempting to do any work such as this, because you risk electrical shock and DEATH as a result. If you are uncomfortable working on an espresso machine DO NOT attempt this repair.

This repair has not been recommended to me by LM and is suggested by me with no guarantees whatsoever. I take no responsibility for any damage you may cause to your machine by virtue of your following these suggestions. Proceed at your own risk.

Good stuff, Ken.

I've been lucky so far -- no excessive noise or vibration. But I use the tank, so I wonder if in some cases plumbing-in aggravates the output hose tension problem. Perhaps the stiffness of the input hose moves the pump enough to put too much tension on the output hose, or something like that. I can move my output hose a bit through the hole in the top left front of the machine, so it seems to have enough slack. If I put little tension on it, the noise and vibration increase, as you found.

Perhaps those who have had noise/vibration problems with the GS3 would comment on whether they use the tank or are plumbed-in.

Peppersass wrote:. . . I use the tank, so I wonder if in some cases plumbing-in aggravates the output hose tension problem. Perhaps the stiffness of the input hose moves the pump enough to put too much tension on the output hose, or something like that. I can move my output hose a bit through the hole in the top left front of the machine, so it seems to have enough slack. If I put little tension on it, the noise and vibration increase, as you found.

Perhaps those who have had noise/vibration problems with the GS3 would comment on whether they use the tank or are plumbed-in.

This was something that John Blackwell had suggested to me (that it was the way I'd plumbed in the machine that was causing the problem). This was not the case with my machine, and I even went so far as to remove the plumb in setup and to replace the original inflow tubing, then running this tubing into a jug of water. It made no difference. In the case of my machine, the input line is slack and puts no pressure on the rotary pump.

Basically, there is very little room for error in how the rotary pump is positioned in this machine. I guess you could view this as either being a design flaw or a "feature." Anything that gets the pump out of its exact correct position will probably result in vibration and noise problems when the pump motor is engaged.

ken

my machine which is not plumbed in and was just built in the end of July does not vibrate, except for the top tray, which is probably normal for any machine with cups on it.

Perhaps these problems are on "older" machines and have been addressed ?

misterdoggy wrote:my machine which is not plumbed in and was just built in the end of July does not vibrate, except for the top tray, which is probably normal for any machine with cups on it.

Perhaps these problems are on "older" machines and have been addressed ?

First, thanks for the photo essay; I enjoyed looking at the pictures of the factory.

After becoming familiar with the internals of the machine, especially as regards the rotary pump and its connections, I believe that this problem is a design issue that has to do with there being a whole lot of "stuff" crammed into a small area, with small clearances in between the various parts. They also decided to use a rather short braided hose that exits with the outflow water from the rotary pump, which goes in front of the brew boiler and behind the front panel. If that hose had been made a cm or two longer, perhaps this would have eliminated the risk of the hose becoming too tight and, hence, transferring the vibrations of the pump and motor through to the case. Of course it is possible that elongating this hose would have caused other problems, so I can't say with certainty that a change of this sort would be beneficial.

Given the fact that everything is fairly tightly packed inside the case of the GS3, there is little room for error in the positioning of any component that is capable of being moved, such as rotation of the rotary pump along it's mounting collar with the motor.

After seeing your photos of the factory, combined with my general knowledge of the quality of construction of LM machines, I doubt that my machine (or others that vibrated) left the factory in that condition. Rather, it was either minor shocks occurring during transportation, or simply changes in material over time, that allowed the internal parts to shift a little bit, resulting in this problem.

So, no, I don't think there has been some sort of significant redesign of the machine, and that newer machines don't have this problem because LM found a source to the problem (other than maybe a slightly too short braided SS hose on the output side of the pump). The only solution to the problem would be to either elongate the braided hose (and I don't know if that would really work), put some sort of vibration damping material around the braided hoses if there is room for it, to use smaller components, or to increase the size the GS3's case in order to give more room in between the parts so they can't come in contact.

The above may have implications for someone who moves his machine around a lot, using it as a pourover. I doubt that this would be a problem for use of the machine in one set location. And, as I indicated, if one is proficient in the use of a screwdriver, and has a little bit of common sense, even if this adjustment would need to be done every year or two, it is a 5 minute fix.

I don't see any of this as being a reason for avoiding this machine, it is rather a quirk to be familiar with in the same way that every machine has quirks that one becomes familiar with over a period of ownership.

ken

I went to the factory to actually avoid it being shipped, as I felt that shipping could be a problem. I mean even just going on to a truck to Paris and off and then on to another truck to my area and a few other minor local trucks before getting to me. I took the machine, put it in my car and drove home with it.

The way the machine is packed is sturdy, but being moved around has to have consequences.

Now add international shipping boats, planes what-ever in to the equation of anything with lots of trucks and sometimes brutes handling things anything could happen.

I used to buy and ship a lot of Hifi Equipment, $10,000 amplifiers each and shipping is the most likely place for accidents.

Still, I would think you could tighten anything that gets loose and get it back into position.

Mine does not rattle, vibrate or do anything except make perfect coffee almost everytime out

Ken Fox wrote:Basically, there is very little room for error in how the rotary pump is positioned in this machine. I guess you could view this as either being a design flaw or a "feature." Anything that gets the pump out of its exact correct position will probably result in vibration and noise problems when the pump motor is engaged.

A little follow-up on this:

It was suggested by Chris Coffee that I try changing the pump orientation to see if it affects the low flow rate on my GS/3. Alas, no, but in the process I ran the machine with the rotary pump at the two extreme positions allowed by the attached hoses. There was no excessive vibration in either position.

That said, If I grab the output hose and pull it against the boiler, then yes, the machine vibrates a lot.

Maybe there's variation in the length of the output hoses.

Peppersass wrote:A little follow-up on this:

It was suggested by Chris Coffee that I try changing the pump orientation to see if it affects the low flow rate on my GS/3. Alas, no, but in the process I ran the machine with the rotary pump at the two extreme positions allowed by the attached hoses. There was no excessive vibration in either position.

That said, If I grab the output hose and pull it against the boiler, then yes, the machine vibrates a lot.

Maybe there's variation in the length of the output hoses.

Hi Dick,

That would not surprise me. Braided SS hoses are a commodity item, and it is possible that they have used different lengths depending upon what they had in stock or could find available at differing points in time. It would not surprise me that you could just have a bad rotary pump, and that replacing it would solve the problem.

My impression is that changing out the rotary pump would not be a huge job. There are only 3 apparent points of attachment, the input and output braided SS hoses (or if not plumbed, then the braided output hose and the input line from the self contained water tank) plus the flange with the pump motor. Perhaps Nicholas could comment since he has removed his own rotary pump recently.

ken


ken

Ken Fox wrote:My impression is that changing out the rotary pump would not be a huge job. There are only 3 apparent points of attachment, the input and output braided SS hoses (or if not plumbed, then the braided output hose and the input line from the self contained water tank) plus the flange with the pump motor. Perhaps Nicholas could comment since he has removed his own rotary pump recently.

You're correct; replacing the pump (not the motor) is one of the more trivial tasks you could do. Decoupling the pump from the motor can be a little tedious in the small space you have to work in (the flange sometimes wants to jump the threads it rides on as you try to loosen it), but it's very doable.

If you want to get the motor out as well for a pump outboarding, that task is much more involved, as I've mentioned in a couple of places--you basically have to unhook the steam boiler connections and the mounting bolts and pull it out to get enough room to take the motor out. Sadly, it wasn't designed to install from the bottom (which would have been a very good idea). The only reason I can think of not to make it that way is that it might reduce the rigidity of the frame to have a motor-sized hole beneath the pump. As it is, there's a small hole covered by a strange stainless sheet whose function I can't figure out.

Not to excuse any design limitations that may exist on the GS3, I did once ask Angelo Minicozzi and Michael Teahan (former master technicians and current owners of a large espresso parts business in California) about the frequency of rotary pump MOTOR failures. They told me that although the pumps do fail regularly, the motors fail rarely. So, it is probably unlikely that one will have to replace the motor, but very likely that the pump will need replacing or rebuilding.

ken