Buyer's Guide to the Quick Mill Alexia - Page 3

[Beavis]

Great clip, Dan. Does the PID read 222? What is the reading on the PID when you hit "BREW"?

[jesawdy]

Great clip, Dan. Does the PID read 222? What is the reading on the PID when you hit "BREW"?

The Alexia PID kit manual indicates that the set value (SV) will be approximately 26°F higher than the actual brew temperature. The kit comes preset with an SV of 230°F and suggests adjusting by taste to a lower SV setting if you prefer a lower brew temperature (I'm sure Dan has determined his temp via a Scace thermofilter).

[Beavis]

independently verify the water brew temp and let us know the exact temp differential between the SV and the brew water temp. I'm thinking this may be the machine to upgrade to from dear miss Silvia.

[HB]

I believe the offset is 24F for my evaluation model, but it will vary depending on the thermowell probe placement. Next on my list is to post a plot of the typical temperature profile. I've been using the Alexia as my evaluation setup for the Titan Grinder Project and noted how it recovers very quickly; I'll measure a series of thermofilter pulls to quantify intershot variance later tonight.

[HB]

As promised, below is the brew temperature profile of the PID'd Quickmill Alexia. This was the first 30 second pull after being idle for an hour. To warm the group, I drew 3 ounces, let the boiler recover two minutes, then recorded:


The PID setpoint value is 221F

For the Schomer disciples out there, the raw data is below:

Table:

185.3
187.9
192.7
196.5
197.1
197.3
197.5
197.7
197.7
197.7
197.5
197.5
197.4
197.3
197.3
197.3
197.3
197.3
197.5
197.5
197.6
197.7
197.7
197.7
197.7
197.9
197.9
197.9
198.0
198.1

The target temperature is 198F. There is an ever so slight rise to the temperature profile towards the end. To see how the Alexia performs under load, the series below are the maximum temperatures at different recovery intervals. The draw was for 30 seconds and the datapoint was the maximum temperature recorded with a Fluke 54-II digital thermometer and thermofilter:

1 minute 30 seconds: 198.1, 197.8, 197.6, 197.5, 197.4
2 minutes 0 seconds: 197.5, 197.5, 197.4, 197.5, 197.6
3 minutes 0 seconds: 197.7, 197.9, 197.9, 197.8, 197.9

These are the best intershot temperature consistency measurements I have ever recorded.

Note: This evaluation model is a slightly modified version of the PID kit offered by Jim Gallt / Chris' Coffee. When I did a few quick measurements of the original PID configuration, I noted temperatures would trend upwards. I noticed this same tendency with my PID'd Amica and added a manual cutoff of the heating element to reduce overshoot; I figured it might improve on the Alexia's already impressive performance. I contacted Jim about this and he sent me a cutoff relay for the heating element whenever the pump was engaged. While the difference in intrashot brew temperature is likely beyond the abilities of mere mortals to taste, the cutoff relay has the added benefit of eliminating the "aaaa-eeee-aaaa-eeee" sound of the pump as the PID cycles the heating element on and off during an extraction. At this price point, I believe the enhanced usability and elimination of the pump pressure zig-zap due to heating element cycling is worth it, but Chris/Jim haven't decided on the cost of this option.

[cafeIKE]

Mind running a series or two out to 50 seconds?

As the 30 second shot time starts at first drops, not pump on, the 30 second series is only 2/3 of the way through the shot.

[HB]

As the 30 second shot time starts at first drops, not pump on, the 30 second series is only 2/3 of the way through the shot.

I don't understand your comment. Let me elaborate on the details behind the measurements posted above.

These measurements were taken using a thermofilter and the first "drops" show up in around five seconds. The thermofilter yields 70 mls in 30 seconds from pump on. But just for giggles, I tried a 50 second pull just to see how much the tail end temperature would rise. Specifically, I did a warmup flush of 3 ounces since the machine was idle for over an hour, let it recover for a few minutes, then ran the pump for 50 seconds. The cup contained 124 mls and the finishing temperature was 199.1F. A couple minutes later, I double-checked that a 30 second pull was 70 mls and the finishing temperature was 198.0F.

[Marshall]

I noticed this same tendency with my PID'd Amica and added a manual cutoff of the heating element to reduce overshoot; I figured it might improve on the Alexia's already impressive performance. I contacted Jim about this and he sent me a cutoff relay for the heating element whenever the pump was engaged. While the difference in intrashot brew temperature is likely beyond the abilities of mere mortals to taste, the cutoff relay has the added benefit of eliminating the "aaaa-eeee-aaaa-eeee" sound of the pump as the PID cycles the heating element on and off during an extraction. At this price point, I believe the enhanced usability and elimination of the pump pressure zig-zap due to heating element cycling is worth it, but Chris/Jim haven't decided on the cost of this option.

I never thought of using it that way, but Michael Teahan built the same capability into my Zaffiro, when he added an independent pump switch. As long as the levetta is up (to divert the water flow to the brewhead), I can flick off the main switch and flick on the pump switch to get the same effect. Must give it a try ....

Up to now I've just used it to empty out the boiler for descaling without risk of burning out the heating element.

"Bionic Zaffiro" here: http://home.earthlink.net/~mrfuss/.

[cafeIKE]

As the 30 second shot time starts at first drops, not pump on, the 30 second series is only 2/3 of the way through the shot.

I don't understand your comment. Let me elaborate on the details behind the measurements posted above.

Timing clarification:
First drops appear about 9-10s after pump on for an actual shot.
Typical shot runs about 30s for about 60ml. 30s begins after first drops appear, for a total of about 40s.

The 30s series initially posted would be about 10s shy of the end point of an actual shot.

Thanks for the additional runs.

[HB]

The 30s series initially posted would be about 10s shy of the end point of an actual shot.

I suppose it depends on whether you measure by volume or time. As discussed in the thermofilter review, the thermofilter was designed to measure the boiler's output, not precisely recreate the coffee's brew temperature profile during a real extraction. Its strength is the standardization of where and how it measures.

Comparatively speaking, the Alexia's shot to shot brew temperature consistency is on par with the La Marzocco GS3 IF you're moving at a leisurely pace. The Alexia would fail miserably if subjected to the WBC Procedure for Measurement of Brewing Water Temperature protocol, excerpted below:

5.3 Testing pattern:
Specification: The length of the idle interval for item A of the Test Procedure shall be:

But for the less hurried espresso only drinkers who prize inter and intra temperature stability, the PID'd Alexia eliminates brew temperature management concerns.

[jesawdy]

Quick Mill Alexia - PID Kit installation

If you have been following this Bench thread, you know that one of the unique things about the Quick Mill Alexia is that Chris' Coffee Service has requested that Quick Mill provide the machine with a precut front panel to accept a 1/32 DIN PID controller. Working with Jim Gallt of MLG Properties, LLC, a PID kit is available for $250 extra as a user-installed option. For an additional $50 fee, Chris' Coffee Service technicians will install and test the PID kit prior to shipment.

This post gives a brief overview of the PID kit installation. I will not go over the installation in great detail; the PID kit is accompanied by a 40+ page manual with many pictures and detailed instructions. The instructions are very clear and I think most* people would have no problems. If you choose to install the PID yourself, read the entire manual first to assure you understand the entire process, and then proceed with the installation. Allow about 1 to 1-1/2 hours to do the installation. This should be plenty of time to complete the installation and double check your work.

Note: If you are not "handy", if these sort of things make you nervous, or if you do not care to become familiar with the internals of your espresso machine, Chris' installation fee of $50 seems more than reasonable for those that want the machine ready out of the box.

Following are a few pictures and my installation notes. This is not meant to be a "How-to" guide; all of the installation particulars are covered in the highly detailed manual included with the kit.

Kit Contents

The kit consists of a Watlow PID controller (model no. SD3C), a Crydom solid-state relay (SSR) and cover, pre-cut wiring with connectors installed, a custom-made thermocouple, a boiler insulation kit, a splash guard, thermal paste, and the necessary mounting hardware and zip ties.


Quick Mill Alexia, PID kit - kit contents (left), boiler insulation kit (right)


Quick Mill Alexia, PID kit - Watlow SD3C PID controller

Remove the case cover and interior "Z" panel

No special notes for this step. Eight screws and I was ready to go.

Remove the brew thermostat and install the SSR

One of the first steps is to remove the adjustable brew thermostat. I had to wrangle with the thermostat and the wiring above it a bit in order to get it out.

The bottom of the machine is pre-drilled and tapped to accept the SSR and mounting screws. Thermal paste is used between the bottom of the SSR and the case for improved heat dissipation. The SSR is then wired on the AC output side following the instructions.


Quick Mill Alexia, PID kit - adjustable brew thermostat mounting point, thermostat removed (left), SSR installed (right)

Insulate the boiler

The boiler is insulated in situ with 1/4" ceramic felt insulation. The insulation is pre-cut to fit around the upper and lower thermosyphon fittings and the OPV fitting. Installing the insulation is not terribly tricky, but I had to pull the boiler towards the back a bit in order to fit the insulation between the boiler and the front panel. In addition, a piece of aluminum flashing is added over the ceramic felt near the PID cutout location. Everything is secured to the boiler with three long zip ties. Make sure you do not get ahead of yourself and only loosely install the top zip tie, and then add the aluminum flashing before installing the other zip ties. A gentle bend of the flashing beforehand was helpful.


Quick Mill Alexia, PID kit - insulated boiler, flashing to right side of boiler

Install the PID controller

I removed two screws from the front panel to remove the PID cutout cover and started installation of the PID controller unit.

This next point is covered in the Alexia PID kit manual, but I want to add emphasis to the following: The boiler and/or OPV may impede the PID controller installation and may need to be repositioned. On my review machine, the OPV at the bottom right of the boiler (see picture above and below) was in the way of the PID controller when sliding it in the front panel cutout. The PID controller was hanging out a full 1-1/2 inches in the front of the machine and touching the OPV at the back of the controller. The boiler is suspended in the case by the upper and lower copper thermosyphon lines and can be moved around. I had to twist the boiler clockwise and pull the boiler to the left (away from the PID cutout) to get the proper clearance. The picture below shows the final relative position of the OPV and PID controller unit. I was surprised how much I had to move the boiler.


Quick Mill Alexia, PID kit - OPV and rear of PID controller (note - no need to remove the brass nut shown)

Once I had the boiler repositioned, I checked that nothing was pinched, rubbing or potentially shorted against the case or otherwise. Specifically, you want to check the heater terminal at the bottom of the boiler (see the picture below). I also found the upper thermosyphon line (on the left side of the boiler) very close to the brew lever pump microswitch. I turned the microswitch from vertical to a 45 degree angle and gained a little more clearance.

The PID controller is then wired for power and to the SSR DC input side following the instructions.


Quick Mill Alexia, PID kit - Check the heater terminals at the bottom of the boiler

Install the thermocouple

A custom made thermocouple is installed in the boiler thermowell. The thermal paste is used again for improved heat transfer. The thermocouple is then wired to the PID controller following the instructions.

Finish up and reinstall the case cover

A splash guard is installed above the PID controller unit. This is installed in case the steam/hot water valve fitting should ever leak since it is directly above the PID controller.

If you are doing this installation, I recommend taking a few moments to double check your work; look for pinch points, rub points (around the vibe pump in particular), and potential shorts as previously noted. All of the wiring is secured with zip ties as you follow the instructions, but I suggest rechecking and rerouting as needed.

Re-installing the case cover is not a lot of fun; if someone is available to assist you, get their help. Since I have had the case cover off a few times now, I have found that it is easiest to install the rear two screws first (these are the longer ones that go into the "Z" panel) but do not tighten completely; follow these with the lower side screws; install the top side screws last; completely tighten the screws as the last step.

That's the end of the installation.

All that is left is to plug it in, power it up and test your newly installed PID controller. Oh, and hopefully have some great coffee as well!

[Marshall]

I think you just sold a whole bunch of $50 pre-installations, Jeff.

[DJ]

If I had not already done so, I would certainly be convinced.

[erics]

As the screws kept slipping out of the hole, Jeff was overheard saying:

Re-installing the case cover is not a lot of fun; if someone is available to assist you, get their help. Since I have had the case cover off a few times now, I have found that it is easiest to install the rear two screws first (these are the longer ones that go into the "Z" panel) but do not tighten completely; follow these with the lower side screws; install the top side screws last; completely tighten the screws as the last step.

If Alexia or Anita or any other machine that has short M4 screws to be removed/replaced on a "regular" basis, these are nice replacements:



These are M4 knobs available from McMaster-Carr (P/N 62935K11, $1.33 each) and rubber washers from your local hardware store.

[jesawdy]

I think you just sold a whole bunch of $50 pre-installations, Jeff.

That was not my intent, but in retrospect, it is probably advisable. If there are any issues or problems with the installation, all responsibility is with the vendor and, of course, they have all the means to fix it in short order. $50 is a small price to pay for that peace of mind.

The kit was really not hard to install, and my 1 to 1-1/2 hour estimate is likely a bit long, but I wanted to err on the cautious side. Also, like many things in life, the first time you try to do something is usually the most difficult. To do it again would be a much shorter and easier job.

If someone was on the fence about getting the kit (and $250-300 for the upgrade is a good bit of change) and went with the stock machine, the user-install kit makes a lot more sense compared to sending the unit back to the vendor for the PID kit installation.

[jesawdy]

<snip>...
These are M4 knobs available from McMaster-Carr (P/N 62935K11, $1.33 each) and rubber washers from your local hardware store.

Thanks for the suggestion Eric. Yes, I see the utility of those screws now. Those are a god send for a tinkerer. The side screws are indeed very short, and, to boot, they are slotted; a Phillips or, better still, an Allen head would make it a bit easier to do it one-handed.

That said, the Alexia is a lot easier to mess around in than Silvia. However, I do wish that more prosumer machines had easily removable side panels (like most commercial machines). Going though a case removal just to tweak the brew pressure, is no fun... it makes you lazy and want to just forget about it.

[RapidCoffee]

Thanks for the suggestion Eric. Yes, I see the utility of those screws now. Those are a god send for a tinkerer. The side screws are indeed very short, and, to boot, they are slotted; a Phillips or, better still, an Allen head would make it a bit easier to do it one-handed.

That said, the Alexia is a lot easier to mess around in than Silvia. However, I do wish that more prosumer machines had easily removable side panels (like most commercial machines). Going though a case removal just to tweak the brew pressure, is no fun... it makes you lazy and want to just forget about it.

I agree! I have very few gripes with the Vetrano, but one is the slotted case screws. Far too easy to have the screwdriver slip and scratch the case. Thumbscrews are common enough on computer cases; why not espresso machine shells? They're inexpensive and very convenient...

[HB]

...a Phillips or, better still, an Allen head would make it a bit easier to do it one-handed.

True, but not everyone in the US has a 3mm Allen wrench in their toolbox.

[cafeIKE]

True, but not everyone in the US has a 3mm Allen wrench in their toolbox.

Could be supplied with the machine.

[Marshall]

I never thought of using it that way, but Michael Teahan built the same capability into my Zaffiro, when he added an independent pump switch. As long as the levetta is up (to divert the water flow to the brewhead), I can flick off the main switch and flick on the pump switch to get the same effect. Must give it a try ....

No dice. Lifting the levetta also powers the heating element.