What is that ugly Allen screw for?

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cannonfodder
Team HB

#1: Post by cannonfodder »

I have had my E61 machine for a few weeks now. I believe I have everything figured out, but there is one nagging question that stares me in the face every time I use it. What the heck is that Allen screw on the brew group for? I know it has to be a standard design on the E61 because I see it on every machine I looked at.

I know I could find an exploded view if I searched for it and that would probable answer my question but I know someone here knows it off the top of their head.

Any chance someone could do a 'care and cleaning of an E61' article. I would like to see how it comes apart so I can do a more detailed cleaning every blue moon. You cannot just unscrew the shower screen and scrub everything down once a month on these monsters.
Dave Stephens

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another_jim
Team HB

#2: Post by another_jim »

A channel has to be drilled from the water stored in the vertical section of the group to the flying saucer section, which has a drill hole going up. This channel is drilled from the front, then sealed with that screw. It's a tempting spot to mount a thermocouple, since you can insert it into the water just as it flows into the coffee, but it turns out to be quite a challenge sealing a TC into there against 9 bar. There's pics up of a disassembled group on CG. You can see an exploded parts diagram here:

http://coffeeparts.com/futurmat/fut1.html

jasonmolinari

#3: Post by jasonmolinari »

Actually Jim, I put a thermocouple in that allen screw, and it wasn't too bad. I bought a 1/16" stainless steel sheathed TC from Omega, drilled the allen screw (i replaced the SS screw with a standard alloy steel so it would be easier to drill). I then brazed the TC in place with silver solder and a propane torch. This was the hardest part, and requires some special acid flux and solder to braze stainless steel.

I did it for about $40 total, including the soldering kit, and the TC. It you want more detailed instructions let me know. I can now hit just about any brew temp within about 1.5 deg. F pretty easily just by flushing more or less to a certain temp, and letting the machine recover more or less...

It is amazing the difference temp. makes on different blends!

jason

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cannonfodder
Team HB

#4: Post by cannonfodder »

I think I may have seen that before, I remember seeing a TC brazed on to the end of a screw. I believe it was on the CG forums. Wouldn't the added length of the TC restrict the water flow through that small channel, or did you cut down the screw so the new one was the same length as the original?
Dave Stephens

jasonmolinari

#5: Post by jasonmolinari »

The new screw is the same as the old, only with a hole in it. I haven't seen any increase in pressure to the group from adding the TC. It is only 1/16" and round, so I can't imagine it creating much of a flow restriction.

jason

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cannonfodder
Team HB

#6: Post by cannonfodder »

I may give that a go one day, for now I am contemplating adding a brew pressure gauge and insulating the boiler on my Isomac millennium. I just finished plumbing it in and adding a filter/softener to the new line. Now I just have to decide, do I want to work on the machine some more or start work on my new home made roaster, going to build a baby Diedrich knock off for 1 pound roasts, or blow up my garage.
Dave Stephens

DanBollinger

#7: Post by DanBollinger »

I mounted a small 1" dial thermometer on mine and despite the time lag, it is useful for temp surfing. Dan

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cannonfodder
Team HB

#8: Post by cannonfodder »

I got to thinking, I have many digital probe thermometers (I work or a restaurant supply company). I wonder if I could shorten the probe length to one inch without damaging the TC. I could get an aluminum screw, drill it out then braze the probe into the screw.
Dave Stephens

jasonmolinari

#9: Post by jasonmolinari »

Do you mean like one of those Polder thermometers? I'm pretty sure they are thermistors, not thermocouples. They are considerably less accurate and less repeatable, and i don't know about yours, but mine are very slow reacting to temp. change....but it might be worth a try..worst case is you waste a screw and a probe.

jason