An update : I've received the hollow bolt (with 5mm diameter through hole) per above recommendation and finally got around to install it. Easy peasy and perfect fit! Once I get a shrink wrap to cover the wiring and I will be all set!

Much cleaner! You prob don't see the wires hidden behind the group unless you look for them

That does look very clean. One thing you might consider is that having the thermocouple very close to the heating element gives you a less accurate picture of the actual temperature than if it were closer to where the water flows in the cylinder. You might be better off with a surface-mount thermocouple located on the side of the cylinder. I found these to be affordable and work very well:
https://www.amazon.com/gp/product/B01NBM7SBK/

Thanks Josh, the hollow bolt is a brilliant idea, it does look a lot cleaner now!

Curtis,
I had the same concern about the probe location, but it seems to correlate quite well with the temp strip mounted 1-2 cm away from the band heater. It was not obvious in the photo but the probe is located within the band's dead-zone that does not contain heating element. I thought about swapping out the probe eventually but laziness/convenience won out! If I were to do this from scratch again, I would get a surface-mounted RTD so I can get 0.1 deg resolution on the PID.

Costs around $14 from Aliexpress:

I am glad that placement is working for you. My group is different so it behaves differently with the sides, rim, and flange all running different temperature profiles.thanks

This mod look great, might do it on mine one day for experimentation's sake!

How have been the shots with it? And what setting do you settle with mostly?

Cheers

fred

Hi Fred,

Thank you! I can't say I've tried every combination of temperature out there, and at my current pace, it's going to be a slow long term test. So far what I've been doing : Set a new temp profile, try it for a week or two before moving to the next temperature combination. Currently I am preferring the low boiler (113C/0.6 bar) and high group temp (81C). But I do plan to compare them more rigourously eventually. I would love to go even lower in boiler temp (I've gone down to 0.1 bar at some point), but the steaming capability can take a toll (I still need to steam some milk for her flat white).

Overall, I don't think the installation has changed the shot all that much (the original config is pretty good), but maybe the celing of shot quality is a tiny bit higher and the bulleye is certainly much easier to hit. Changing brew temp is a cinche since I can set the group head temp to where I wanted with confidence, with just the click of a few buttons on the PID controller (whereas before it's mostly guess works). I just love the fact that the group is 100% up to temp with a 30 minutes warm up time. I felt that that my first shots of the day are more consistent as a result of that.

I might be biased but yes I think all levers should have this!

I couldn't help myself..I have just finished this addon to an Aurora myself.





When I ordered the silicone heater band, I opted for the maximum wattage given the size needed to go around the bottom lip of the group. For the 230 volt application this came to 80Watts (actually measured with a powermeter at 83Watts).

In use, this translates to a sub-20 minute from cold group warmup, ready to go. Prior to this the warmup was 60-90 minutes.

It has only been a few days of operation but so far the performance has been flawless.

The reality hit for me yesterday when I returned from a long day in Sydney. I wanted a quick coffee (or two!) and turned on the Aurora... and was drinking the first one in 20 minutes! Normally this would have been a job designated for the Cremina.

I really like that this modification is completely reversible... but I cannot see why I would ever take it back to the way that it was.

I thoroughly recommend Sam's conversion and commend him for thinking of it, planning it out and for not keeping this a secret.