MicroCimbali Lever

[Makanmata]

In order to distract me from my annoyance regarding the bait and switch scam with the LM GS3 -- which I have waited for for over two years based upon the distributor's continuous, uniform, and ultimately false representations -- and to keep me occupied while I choose a pump driven substitute, I picked up a MicroCimbali lever machine. I have never used a lever machine before, though have read this forum extensively, and seen a vintage Faema home lever -- which seems quite similar to the Cimbali design -- in operation. Can anybody give me any specific pointers about this particular machine? It is surprising to me how little has been written about it. Has anybody owned or used one?

Thanks in advance.

[Makanmata]

I unpacked it today, and decided to play around with it a bit. Fortunately, it came with an original instruction booklet, so I was not totally lost. I am very pleased with the aesthetics of the machine, which is much larger than I had realized, but I did notice a few problems, at least one of which might be major.

The issue that I am worried about is that there is definitely some stray voltage coming out of the machine. I noticed this because when I touched the metallic drip tray, and had another hand on my stainless steel sink, I received a noticeable electric shock. While the shock was not too bad (I could keep my hand there for a few seconds before it got too uncomfortable), I suspect that this does represent a real safety issue. Is this something that I might be able to fix myself (I'm not too handy)? Is this a legitimate basis to send the machine (which was represented to be in excellent working condition) back to the seller?

The other problems I suspect that I could deal with easily enough.

The first is that the piston is quite squeeky when the machine is operated. Can I safely add a squirt of WD-40 to get rid of this?

The last issue is that there are noticable white deposits which can be seen through the sight glass, and the first time I filled the machine up the water was a bit milky? I intend to run some white vinegar through the boiler, which I hope will remove those deposits and have the machine passing clear water.

I suspect that there will be a fairly steep learning curve getting up to speed on this machine. For now, I just want to make sure that the stray voltage doesn't represent a real hazard, and that the squeeking and scale issues can be dealt with

Thanks in advance for any insight you can offer.

[coffeefrog]

Hi makanmata,
"Stray voltage" - yes, definitely dangerous. I wouldn't use the machine until it is fixed. If there is some intermittent short it could get worse suddenly. I'm surprised its not blowing a fuse in your house fusebox.

The squeak - you need a food-grade grease, not WD-40 (no idea what drinking WD40 would do to you) and you'll need to take the piston out to grease the seals. Its probably not hard to open it up.

White deposit and milky water - try a bit of vinegar and then rise well to descale, but it might be that its got milk in it in which case it will need taking apart to clean it.

I don't know the machine at all, but fixing it should not be difficult, lever machines are simple beasts. Is there someone you know who is a bit more handy than you are? I'm sure there are others here who can be more specific than I can, but you should be wary of the electrical problem.

Greg

[timo888]

Agreed, no WD40. Use Dow 111 instead; it is NSF 61 certified safe for potable water applications and has a high melting point. Available on the web in very small packets and in tube of toothpaste size which will not run out for decades, since a little dab suffices.

Advisable not to operate the lever when the machine is cold and no water is present in the cylinder to lubricate the seals.

A GFCI outlet is a good idea.

----------

Others may advise otherwise, but I would grind fine and, if you're going to tamp at all, give it < 1#. That's right, not 30#, but merely the weight of the tamper. You can then focus on dose and distribution and on tweaking the grind. Don't overdose -- leave about 6mm headspace in the basket.

Regards
Timo

P.S. Not much to be found here about the MicroCimbali -- they are relatively rare.

P.P.S Is your MicroCimbali pre-owned or new?

[orphanespresso]

Ditto what Timo said on the lube!

Electrical (we just today had ours apart because we needed to replace the switch). If you lay the machine on it's side, you will see a big nut on the bottom. Remove the nut, and the cover plate for most of the electrical connections comes off. (UNPLUG THE MACHINE FROM THE WALL FIRST!) You will see a plastic junction box where a red wire and a black wire go in, and other wires go out. There is a 2nd bundle of wires - green yellow - basic psychedelic European color wires, that connect to the underplate, with a set screw. These are likely ground wires. There is a big capacitor that is wired in, it is just kind of dangling loose in the space. Just carefully inspect the wires & connections - look for anything bare (no insulating cover on the wire), or loose wires. If everything looks good here - connections tight, and no bare areas, then take off the big nut that holds the base & collar to the boiler. Remove the 2 allen head bolts (be sure to get an allen wrench that properly fits these - it should fit cleanly, easily, and not be loose in the socket of the bolt head). Remove the phillips head screw on the back of the column, where the chrome meets the boiler. When you pull off the lower column from the boiler you can see every wire, and every connection. This is by the way, the only way to replace the switch, which is why we took ours apart just a few hours ago! Again, look carefully at the wires - check for bare wires, and loose connections. If you don't see anything loose, worn, rubbing through the insulation on the outside of the wire, then put it all back together before you forget how it came apart (take digital photos if you're prone to bad memory, or take notes!) and, if you haven't found anything suspicious & obvious, contact the seller or a repair person.

The piston has 2 o-rings, and a cup seal on the rod (the rod goes through the cup seal) that you can lube. There are 2 pins where the lever connects to the rod. It could be the pins squeeking. The fulcrum of the lever is a steel sleeve that sits on top of a brass 'boss'. The pin that goes through the sleeve can squeek. So, there are 2 exterior pins/sleeve that could make the sound - not actually in the gasket to metal part of the movement. The place where the pins stick out of the chrome knuckle that the lever bar screws into - you could put a LITTLE drop of oil to see if that quiets the squeek. But, it seems unlikely that with water in the machine the o-rings would squeek against the cylinder wall.

We did solve all the issues with ours today...except for being one o-ring short of stopping up a BIG leak...

[timo888]

The issue that I am worried about is that there is definitely some stray voltage coming out of the machine. I noticed this because when I touched the metallic drip tray, and had another hand on my stainless steel sink, I received a noticeable electric shock. While the shock was not too bad (I could keep my hand there for a few seconds before it got too uncomfortable), I suspect that this does represent a real safety issue. Is this something that I might be able to fix myself (I'm not too handy)? Is this a legitimate basis to send the machine (which was represented to be in excellent working condition) back to the seller?

It's the kind of problem that could have been caused by bumps in transit -- wires being shaken loose etc. I would not lay it at the Seller's feet, if it had been packed with reasonable care. Best practice is to double-box a domestic espresso machine, with foam separating the inner from the outer box, and lots of protection around the machine itself, and around the portafilter and the other parts. Even then, wires can work loose -- the double boxing protects the machine against crushing and dents/dings.

Regards
Timo

[Makanmata]

Thanks for all the advice, all of which I will certainly follow. I am duly impressed by the wealth of imformation you all posess, particularly given the obscurity of the machine.

I am a bit worried about the electrical issues, as I am not much of an electrician, but I will turn the machine over and see if I can find anything obvious that I could deal with myself. If I can't fix the stray voltage, the machine might have to try to send it back to the seller (I got it from ebay), which would be very disappointing, as I am otherwise pleased with the purchase. I am willing to put some work into the machine, despite its representation as "excellent working condition," but I have kids running around and don't want anybody to get zapped.

Another question. Having examined the machine a bit more, I see that there are nuts that seem to be holding the sight glass to the boiler. Is it ok to unscrew these so as to remove the sight glass and allow direct access to the boiler, in order to aid with the descaling, or is this something that shouldn't be messed with?

Thanks again.

[bill]

Rob,
If you could tell us where in the U.S. you're located someone may be able to suggest a local resource to help you.
Bill

[peacecup]

Stray voltage may also be due to a bad heating element leaking voltage into the water. Don't know how easy it is to find replacements.

If the machine cost $300 or more you might consider returning it. You could probably get a very good condition La Pavoni for that price, and a new Pavoni or Ponte Vecchio for ~$500. FOr my first lever machine I opted for the latter, because I too have kids (PV has a boiler cover), and I was not up to a restoration effort.

PC

[orphanespresso]

On the sight glass issue: You take out the 4 nuts, pull the sight glass cover off. The sight glass is sandwiched between 2 gaskets (treat it carefully as you remove it, and remember the orientation so that you can put it all back on in exactly the same way - a tiny mark on the top will help you to be sure which way is up! you should be able to reuse them if you are careful). But, unless you take the piston out, removing the sight glass won't gain you much.

[Makanmata]

Thanks again for the help. I spent some more time on this today.

Firstly, I tried to open up the machine, but was completely confounded by that strange bolt on the bottom. What sort of tool do I use to open something like that?

In any case, I left the electrical issues and tried to check out the scaling issue a bit more. I have always descaled my own machines regularly, and have never seen anything get as bad as this. One can see the large deposits of scale through the sight glass, and lots of sediment comes out of the group head when the machine is run. I decided that the first step to dealing with this was to get the loose sediment chunks out, so that a descaling agent can have a chance to work. As such, I filled the boiler with water, and gently turned it upside down into the sink. What came out sort of shocked me. Large sheets and chunks of sediment fell into my sink. These are of two distinct sorts: whiteish chunks (sort of like clumped Ajax), and grayish chunks (not really much like anything I have ever seen before). What on earth is this stuff? Is this just scale? Or is this perhaps the remnants of a corroded boiler? The loose chunks are all out now, and I'm wondering whether to carry on with a regular descaling agent (vinegar) or if I have a machine with a corroded boiler which might be a problem of an entirely different magnitude?

I do have a local guy who specializes in servicing and restoring lever machines (as well as other Espresso equipment), but I'm not looking to make a further investment beyond the not-insignificant amount which I already spent for this supposedly "perfect" machine. I would still like to keep it though if I can sort these things out myself.

Thanks in advance for help in telling me how to deal with that strange bottom bolt, as well as the magnitude of my scale/corrosion problem. Here are some pictures of the chunks, and the bolt.

[Makanmata]

I also see now that I can't get the pressure to stay up above .2 bar, which I assume is too low. Is there a way that I can adjust the thermostat on this machine? If so, how?

Thanks.

[jamoke]

Quite an impressive mineral collection! Did you buy it from a geologist?
On the thermostat (well, on a lever machine, pressurestat), if it is an older Microcimbali it won't have one. It will have a pressure relief valve, I think at the top of the machine, and a hi-lo wattage switch instead of the simple on-off. But I think the presence of a pressure gauge means that it is new enough to have a pressurestat and a straight single wattage element. The pressurestat is probably in the base, which will mean a tussle with that bolt.
The low pressure could be caused by a mis-adjusted pressurestat, or a mineral-clogged one. It could also be caused by a mineral-encrusted element or the same electrical problem that's zapping your fingers.
Also, the Micro has an aluminum boiler, which can apparently make it more prone to mineral deposits and corrosion. I have heard, however, that it is capable of making good espresso.

Good luck,
Ed

[Makanmata]

Believe it or not, the above is only a small selection of the stuff that has been falling out of the machine. The deposits are so bad that I can see chunks through the sight glass.

I have one liter of straight vinegar in there now, and will leave it to to its work for a bit, and hopefully dissolve the rest.

As far as the pressurestat, I can tell you that I only have a single on off switch, so I'm guessing that there must be a way to adjust the pressure. If I can ever figure out how to get that bolt open, perhaps it will be obvious.

Thanks.

[orphanespresso]

To get the bolt open you can use a flat tip screwdriver on it's side (so you are inserting the flat side of the screwdriver into the slot), if you have a wide enough screwdriver you can put it into the slot & turn as normal. Or, a chisel (not too sharp one!) which is wide enough to fit the slot & a crescent wrench to use as a handle on the chisel to turn it. Basically anything that will fit neatly into the slot (and fit in both sides). All this holds in is the thin bottom plate that covers the wiring connections. Once you have that off, there are 3 more bolts that hold the bottom itself on - 2 allen socket screws, and one brass nut. There is a small phillips head screw on the back, near the boiler (the pressure stat is up in there).

Quite a collection....too bad I can't think of a use for your mineral specimens, other than marveling at them!

It is pretty simple to take apart the piston assembly and the housing parts above & below the piston - it would open it up for manual descaling.

As far as motivation - we got pretty close to a god shot with ours today, just missed it by a bit, and it makes nice dry steam - it really is worth fixing!

[mogogear]

The vinegar can work fairly well on light scale- BUT- If you have access to a home brewing / winemaking shop- go but some bulk citric acid. Inexpensive and really effective on scale such as yours.

It is the real deal and will help resolve the build up issue- which looks sizable !

[Makanmata]

Indeed, the scale is looking at the vinegar and laughing at it. After several hours, I can still see big chunks through the sight glass, and worse still the grouphead, water tap, and steam arm are all intermittently blocked by mineralization. Drastic measures are called for.

Unfortunately I can't locate any nearby homebrew supply stores. Can I get this stuff elsewhere without having to order it (a pharmacy, hardware store, or somesuch)? How do I use it? Is it a powder? Should I fill the boiler up to the top? How long can I safely keep it in there?

I am hoping that all of my problems are related to the scaling? Right now water is coming out of the tap at 195 Degrees F, which seems a bit low, but I am hoping that things might pick up once the boiler and pressurestat are unburdened.

Thanks again to all.

[mogogear]

Yeah, don't sweat the temp- your in the ballpark... the de-scaling may not solve all your problems but ..... Do you haver a coffee repair service located in your phone book? They almost always have little packets or bulk used to clean and descale commercial coffee makers.

I find most places like this if you just drop by and tell them you are a espresso nut and that you have a "antique" espresso maker you need to descale- .. and could you please buy a small amount... etc etc etc

For about $5 you can get hooked up with some effective stuff. Tell them you are looking for citric acid- see what they say .

As far as amounts- repeated use may be more effective for you.

A possible scenario would be ; add 2 tsp - fill with water- heat up and then leave on for 10 minutes. Let it cool down- then heat up again for 10 minutes. You might try this for about 3 cycles or so and then leave the solution in till the next day.

Add some fresh stuff and do it all again. See where you are at..

Good luck

[Makanmata]

I put this project away for a few days, and upon picking it back up, things seem to have gone from bad to worse. Somehow, the water tap has now seized up, and the tap is stuck in the slightly on position, resulting in a constant drip.

I unscrewed the nut holding the wheel in place, and now see that it is just not "grabbing" the "axel" that seems to actually open and close the tap valve.

I'm thinking that I might have done some damage to the tap by passing some of the freed up chunks of scale through it to get them out of the machine. Any advice on how to deal with this?

I'm hoping that perhaps it is just clogged by a piece of scale, and that once I get my hands on the citric acid, I can burn it away to the point where it will pass through -- sort of like a kidney stone. Is this just wishful thinking? What is going on?

[narc]

Citric Acid USP should be available from most pharmacies. If not in stock they should be able to order some from their wholesaler/supplier. The last 454gram container (Humco, NDC: 0395-0605-01) I purchased couple years ago retailed for $18.73. The pharmacy sold it to me for $12.92.

After a few season of use, the electrodes on a room vaporizer (humidifier) was coated with a layer of scale. After soaking overnight in a solution of 50gm of citric acid/ L of distilled water scrubbing was still required plus an additional few hours of resoaking to completely remove the deposits. I would seriously consider sending the espresso machine to a shop for a professional deposit removal.