barry wrote:what's the point of an aesthetically pleasant digital display that is essentially useless?

It would be nice to have a plug-n-play option that doesn't rely on anything more than entry with an M6 screw. I've suggested it several times to mod-minded vendors as a post-factory installation option. No takers yet.

Eric's TC adapter gives valuable information for a relatively low cost - less than $100 complete with a cheap PID used to display the temperature. But it does impact the natural beauty of an E61. How much one is willing to invest in correcting aesthetic issues depends on how much it offends. For example, it wouldn't be exceedingly difficult to mount the PID readout in the case (cutting out the square in the panel is the hard part).

La Valentina has a "cowling" covering the top of the E61 grouphead, so it isn't much of an issue for me. I routed the TC wire out the back of the machine where it plugs into the Fluke 54. I can see it behind the grinder and it doesn't detract from the machine's frontal view.

Eric goes to great pains to describe the precise positioning of the probe in the E61 channel. Initially I pushed it as far down as it would go because what I was really after was the (highly reactive) HX output temperature, not the brew temperature. From the prior page:

Medium delay (5-7 minutes). Result: 201.5F

In the end, I settled about midway between Eric's "D" point turn and the bottom of the well. The probe temperature varies by placement, boiler temperature, machine HX design... in other words, you have to tweak the technique a little for each machine. The good news is they behave similarly, so it's a one-time tweaking that you can either do by taste or thermofilter.

So what's my point? That a probe installed through the back of the E61 entering the valve chamber might yield good data:



In this diagram, Eric shows "D" as the position of the turn. I put a probe all the way to the bottom for the Vetrano (it touched the cam lobe) and for La Valentina (no cam lobe, just an empty chamber since it has a solenoid). The readouts were more volatile and demanded your attention to catch the transition point, but the taste and thermofilter readings confirmed that I was consistently hitting within a 1.5F range centered around the target, which isn't shabby for such a low-tech low-cost solution.

Of course this means tapping threads... but that also eliminates the need for a custom adapter. Any old off-the-shelf Swagelok will do. Oh, what we do for looks.

barry wrote:doesn't "been there, done that" count for anything anymore?

Meta-comment: I thought your comment about F!F! was kind of funny, but it helps that I know you and your curmudgeonly ways. Plus I don't mind hearing the cold hard truth from time-to-time.