arcus wrote:I'd prefer to come by and taste the espresso from the working prototype

That can also be arranged!

Fantastic. Thanks for all those pictures. Really inspiring.

Update on the build for mid Februrary:

1) it is still winter.
2) all rain forest accoutrements are now complete!

Here are the finished handles: sanded, oiled and with their brass inserts installed.



In place on the machine (and photographed under unflattering neon lighting in the shop).



Oh, and that would be a completely plumbed and wired machine that the handle is attached to .



Again, under the shop lights, the wood looks a little orange...



With all the other wood details on the machine I just couldn't not make a portafilter handle:



The full process is here

Those knobs look amazing. Very curious on how they feel in operation

"Oh, and that would be a completely plumbed and wired machine that the handle is attached to : ."


Great news!
How does she go?

napierzaza wrote:Those knobs look amazing. Very curious on how they feel in operation

Thank you! That is an interesting question. The portafilter has a nice heft to it because of the brass and I prefer the texture and shape to the plastic hands down. The steam and water handles have a different feel to the original - lighter would be the best way to describe it. This is partly to do with the wood being considerably less dense than ABS, but also because the new valves have a different internal mechanism. The originals (made from unobtainium) are like traditional tap valves in that the seal is compressed by the stem screw when you close the them - the tighter you close, the tighter the seal. With the new valves, the seal is achieved under spring pressure. Closing the valve allows the spring to apply its force to the seal. The upside is a constant closing force (and therefore probably a longer seal life). The downside is that there is a little bit of a 'dead zone' in the last eighth of a turn or so of the handle.

Paolo wrote: How does she go?

Haha - testing has commenced and all will be revealed in a subsequent post but here is a sneak preview.

Thomas, ever consider making the porta filter out of polished Stainless Steel.
Since switching to a S.S. P.F. on a Europiccola I noticed the P.F. does not stain as it use to, cleans easily and imparts no taste.

That is interesting. I had no plans to make the PF they are a standard part. I do find that they wear out after a while though - so a SS version might be worth considering. Of course, a naked PF solves both of the problems you mention too

A recap of the group cap! This part has been a tail of (minor) woe for a while now.



I was all happy when I got the first batch out of the box what-seems-like-oh-so-long-along-now. Until that is, I put them on top of the group and discovered that the color of the chrome didn't match. That micro tragedy was joined by a second, rather more important problem: like, ya know, it don't fit! Seems like someone can't read their own writing: I made a transcription error when I was making the drawing for the part and the slot for the lever is 22mm wide instead of 32mm!

The first problem is easy to remedy with some sandblasting and a trip to the chrome store. The second one requires some slightly stronger medicine.

This cap was sandblasted down to at least the copper layer under the chrome. The 1/4" endmill is just long enough to reach the bottom of the curve at the perimeter of the cap - which is a bit of luck as otherwise this would be a bit more tricky to CNC.



The 1/4" bit leaves the appropriate radius in the corners of the slot.



The other half of the slot has to be machined with the chuck axis parallel to the table. This setup required a little bit of head scratching and some laaaaaarge clamps.



This isn't the stiffest of setups, so light cuts are in order.



All done - except for deburring (and sandblasting and re-chroming, (very small sigh)).

Great work on the cap! How many more do you have to fix?