I noticed that Orphan Espresso is selling an aluminium heat sink to extract heat from the group that fits several machines with 49mm portafilters such as pre millenium La Pavoni machines. Has anyone tried these? This seems like a good idea.

This device could certainly be improved by making the device from other metals.

All metals have heat capacity of about 3R per mole where R is the gas constant. Thus this would certainly work best if they used a metal with high heat conductivity and low molar volume. Cu has an extremely high heat conductivity and one of the lowest molar volumes for usable metals. Its conductivity is about double aluminium, and about 3.5 times that of brass. Since its molar volume is also much smaller it can soak up much more heat per volume.

However Cu is rather expensive and TERRIBLE to machine, though there are alloys that maintain the high conductivity and that can be machined. The chunk of metal needs to be about 75 mm in diameter.

I wonder why they did not put portafilter type handles on the one sold by Orphan Espresso. It would be easier to handle that way.

I have it and use it all the time. Works like a charm and its very effective. If you pull more than 2-3 shots on say Cremina you simply must have this... You could indeed lock in cold portafilter but 3rd shot is faster to bring group temperature down. I keep it in fridge so it works very fast first time its used...

You certainly know your chemistry way better than I, but when I look up the volumetric heat capacity of various metals (see: http://en.wikipedia.org/wiki/Heat_capacity) it looks like aluminum, while not the best, is in the ballpark and justified by cost and ease of machining. People that need to do a little filing of the ears to get a perfect fit in the machine will be glad that it's aluminum as well.

Not having a handle could be viewed as a plus - makes it easier to store the thing in a space-limited fridge or freezer.

I've used two group cooldown gadgets: One is a stock portafilter I keep in my freezer (I always use a bottomless to pull shots) and the other is a cheap (5 bucks) flexible re-usable cold pack that I also keep in the freezer. The PF doesnt work very well at all, but the cold pack works great - I wrap it around the group and hold it tight, and it can drop the group temp 10 degrees in less than a minute.

I'm sure the OE 3rd shot is way better than the cold brass PF, and would have one advantage over the cold pack - you could lock it in and go back to grinding and dosing your next shot. I may decide to go for it.

I've got the OE 3rd shot. It works like a charm. In fact, over the holidays with large family dinners etc I would: pull two shots, use 3rd shot, rinse in cold water and put in fridge while pulling the next two, etc and my temp stability was excellent. This made for very good shots for many people. Really, my only limitation was the tank running low.

I'm sure the portafilter-like handle would be convenient but likely would increase the cost. I also store in fridge and having a handle would be slightly more cumbersome. My only concern is the black rubber around the bottom would get old and brittle. looks like one of those trendy rubber bracelets so should be easy to replace. I've always got a towel nearby so could grab with that in the future.

Highly recommend to anyone who has a 49mm lever. Now if only Doug and Barb will make other sizes like for my Pavoni Millenium.....

tekomino wrote:Works like a charm and its very effective.

benhogan wrote:It works like a charm.

OK, now I'm sold - just added one to my OE shopping cart. When making coffees for guests, my process is way complicated (and downright goofy to some.) Replacing the Walgreens cold-pack step should help.

P.S.
If I have over 4 guests I make drip, or get out the Moka pot. My hat's off to you folks that can use a LP to serve more than a few guests.

Pssst.....it fits the Millenium too, and the band is silicone!

Doug (and/or Barb) Thanks!!! I never even thought to try on the Millenium. I'll need to update my prior post I really really really like it now

Got one coming in for my Millennium Gaggia Factory.

yakster wrote:Got one coming in for my Millennium Gaggia Factory.

Please bring it to our 2/11 gathering. We'll have lots of levers for trying it out. I'll also bring my OE Slapshot and leveling tamper so others can try them.