maximoe wrote:Ok so after deciding that I would like an E61 group , I have noticed that they have two input threads on the back. I won't be recirculating through a heat exchanger so am I correct in dating that I could just block one inlet and plumb the pump direct to the group?

Of course I would then just flush the group with water in order to pre heat.

If you don't have a thermosyphon loop, the grouphead will idle too cold. The Quickmill Alexia is a single boiler (non-HX) and it has lower/upper boiler connections to the two corresponding ports on the back of the E61 grouphead.

maximoe wrote:Of course I would then just flush the group with water in order to pre heat.

Wow! That's going to be a LONG flush! There's alot of weight in an e61 group, so you might want to either add in the thermosyphon or find a way to rig up an electronic group heater if such a thing can be fit into an e61.

(FYI. My Bezzera Strega has a lever group heated by 2x50w heaters. This 100w heater pair takes about 15 minutes to heat up the group. Boiler takes 5 minutes to heat up before the group heater kicks in.)

Lots of designs out there. It all looks simple until you start looking at the details...

Ah that makes sense, before looking at this image...

I had a tough time figuring out how I would implement the thermosyphon, but I should not have a problem making that work at all. Thanks guys! Now as far as implementing this with a single tank, I think I'll just plumb it in straight from the bottom of the boiler water.
Thoughts on that?

Well, that is a diagram of a HX. Are you going to do that, or go with a single boiler design (slightly less complicated)? Maybe you should go for a double boiler You can avoid an autofill if you use a sightglass (but autofill would be preferred).

I'm going to do this, but with a single boiler and supply the HX with water from the boiler. I can go for a double boiler later if I decide I need it. For now I just want to get the thing running haha.

Maybe a stupid question... I found a solenoid E61 group online, with no solenoid on the bottom... Is there any way I can get around that? Maybe just mount a small valve to purge with?
Here is what I'm talking about.

Finding cheap stuff is tough!

Ignore that last post. As it turns out, crappy used ebay stuff has got nothing on Stefano over at espressocare.com. After some emailing back and forth he managed to find me a group that has been kicking around warehouses for a few years, along with a portafilter to go with it! I am going to be waiting impatiently like a kid at Christmas for the next week!

Other than that, got some work done on the heat-exchanger today. I worked on creating a spiral out of the copper to give the loop more time in heated water. I might try to double it up in there, but we will have to see.

First bends:


Quick fit check:


More bending:


More fit check:


Rough outlet configuration:


As seen in the last image, the pressure gauge for the group will come right off the top of the HX. The "T" part will go directly into the back of the group, which will continue down to where it will T at the bottom, and the pump will pressurize.

That's it for now, time to start thinking about the full layout of this thing! Not to mention finding some sort of worthy brass or copper pipe to serve as my reservoir. If you havent guessed, I'm kinda going for a steam-punk/mad scientist look.

You will want your pressure gauge on the cold side of the equation. Most are not rated for high temperature water, and the hot water will shorten the life of the gauge.

Thats great. Glad you got the group you really wanted.
I've done several orders with espressocare and he gets stuff out the door and into my grubby hands very quick.

cannonfodder wrote:You will want your pressure gauge on the cold side of the equation. Most are not rated for high temperature water, and the hot water will shorten the life of the gauge.

Good call, what I will do then is extend it a ways away from the hot water to cool it down... I suspect as long as I seal it with only air in there, when I turn on the pump, an air pocket will form and insulate the pressure gauge.