The Carola is a single boiler espresso-only machine with an E61 group. The unit measures 12-7/8" tall, 7-15/16" wide, and 15-1/4" deep. Out of that 15-1/4", the main body of the machine measures 9-7/19".
There is a stainless steel cup warming tray measuring 0.030" or about 22 gauge (0.762mm) thick which must be removed in order to fill the machine.
This is really not a problem - if you store the machine on a kitchen countertop under a set of top cabinets, there really is not enough room to store cups on top of the machine anyway.
Removing the cover reveals a sticker which ways:
QUICKMILL Sri - SENAGO
Made in Italy
120V - 50/60Hz 850 W
The reservoir is a removable rectangular plastic container measuring 6-1/4" tall, 6-3/8" wide, and 3-3/4" deep. It holds about 1-3/4 quarts of water when full.
Three clear plastic hoses extend into the reservoir. The pump intake hose has a clear plastic filter attached to the end to filter the water before it enters the pump.
On the left front of the machine is a single on/off power switch, a green power light, and a red heater light.
On the right front of the machine is a 0-16 bar pressure gage labeled "Quick Mill". The face of the gauge is white with black lettering. The band from 8-10 bar is colored green, and the band from 10-16 bar is colored red.
The E61 group feels very prominent in this machine, probably because of the chassis' narrow width. The brew lever sits to the right of the group, and attached to the brew lever shaft is a cam which actuates the machine's pump through a black-capped microswitch. I have seen the debates about whether the brew lever on the E61 group has two or three positions. All I can report is that on this machine, there is a definite feeling of a detent position as you raise the brew lever prior to when it engages the microswitch.
The case, which I measured at 0.061" thick or about 16 gauge (1.55mm), is made out of stainless steel and is attached to the frame by five screws; two at the front on each side, and one in the back. It is a very good idea to have a towel under the machine when you remove the cover, because you might scratch your countertop if the cover unexpectedly drops on to the counter when you remove the last screw.
Once the cover is removed, there is a sturdy interior frame which is made of 22 gauge steel, upon which the water reservoir sits. This frame attaches to the front panel by two Philips screws at the front/top of the machine, and the case screw at the back. One note regarding these screws that shows that Quick Mill pays attention to details - these two screws seat into blind nuts embedded in the frame. I am guessing this is because the frame is thinner than the case, where the screw holes have simply been tapped.
If you remove the three clear hoses from the interior frame and remove the two screws I just mentioned, you get a Most Excellent reward. The machine neatly lays out in two pieces! (Thank you to whoever designed this machine.)
This provides excellent access to all the internal components. In fact, you can power up the machine in this configuration, since you do not have to disconnect anything to separate the frame from the front panel.
Opening the machine reveals the boiler, nestled in a bottom support frame - the boiler is not physically mounted to this frame, but the frame supports it, keeping the boiler from being supported solely by its fittings.
There are three boiler fittings. The feed running up to the group, a group return, and a water feed from the vibe pump. The water pressure adjustment is easily accessible at the output of the vibe pump.
A resettable over-temp sensor is screwed into the top of the boiler, and a ground wire runs directly from the boiler body to the ground lug of the power connector.
There are two other boiler connections - a temperature sensor for the PID unit, and a pressure connection for the front-panel pressure gauge.
The boiler is wrapped in foil insulation, and the holes cut in the insulation for the water fittings were well crafted, not just hacked out.
Wires are neatly zip-tied together and are held out of the way of the boiler. The electronics consist of an Italian manufactured PID circuit board mounted on four plastic stand-offs at the back rear of the machine,
a capacitive water level detector module mounted on a shelf above the PID,
which is connected to the capacitative sensor which is mounted next to the water reservoir.
and a pump relay mounted to the detachable cover.
Note that this relay is a double-pole relay, but Quick Mill only uses the Common and Normally Open contacts.
The vibratory pump is mounted to the bottom of the chassis with two rubber mounts, one at each end of the pump; this reduces noise transmitted from the pump to the chassis substantially. Power to the pump is routed through a sensor which cuts power to the pump if it runs for an extended period of time.
The drip tray cover has a series of holes approximately 1/4" in diameter through which liquids pass into a drip tray positioned below. There is a 7/8" diameter hole at the back of the cover to allow the discharge from the bottom of the E61 group to rapidly pass through the cover and into the tray itself.
Removing the drip tray cover reveals a 1-5/8" tall, 7-1/2" wide and 5-3/4" deep drip tray. As I noted before, the finish on the drip tray corners is a little rough, and the exterior surface of the drip tray at the corners was sticky with flux.
The machine runs on a 110 volt 15 amp conventional electrical circuit. The power cord is not permanently wired to the unit. Instead, there is a IEC 320 C14 connector (similar to a computer power supply) on the back of the machine. This allows you to easily replace the stock cord with one that is an appropriate length for your installation. My machine shipped with a massive 8' long, 3/8" diameter cord. I have the machine situated about 10" from a counter top outlet, so that is a lot of cord to hide behind the machine. I ordered a one foot long cord from Amazon for about $2.50. The IEC60320 specification says that this connector is rated for 10 amps. When the heater is on, my amprobe measures about 6-1/2 amps, so the machine is pulling well below the maximum current for the C14 connector.
On the bottom of the machine, there are four black rubber feet, attached with M5 nylock screws. The feet leave marks on my counter top, so I will be changing these in the near future. The feet get a very good grip on the counter top, and the machine does not scoot around when I am securing the portafilter.
There is a removable cover which provides access to the boiler terminals, and in a very nice touch, it is held on with two M4 cap nuts, preventing you from accidentally scratching your countertop with bare 4mm screw ends.
Looking through the hole in the bottom, you can see the heater element and the bottom of the boiler. It appears that the heating element is removable, which is great news if you accidentally run your boiler dry and burn out the element.
One note about putting the machine back together. I put the interior frame back in the machine, screwed down the two screws at the top of the frame, put the four front cover screws back in, and then could not get the single screw at the bottom in the back to go in straight. Looking in the hole at the back of the unit, I could see that the interior frame was mis-aligned. I took the machine apart and found that the base of one of the PID standoffs was keeping the frame from seating properly because it was rotated 90 degrees. I rotated the standoff 90 degrees and this allowed the interior frame to sit flush at the back of the unit.
I checked the alignment and everything was perfect.
While I had the machine open, I drew out an electrical schematic which I will post the next, along with an electrical 'theory of operation'. Hopefully this will help anyone who has electrical problems with the machine.
For now, I think I will go make myself a cup of espresso.