Jian Yi Lever espresso machine - Page 5

#41: Post by **Tjyven** » September 11th, 2022, 12:49 pm

Still waiting for my machine so cant help you but guess I will have the same issue soon then. Do I understand correct that the stone absorbes heat making the thermal control of the shot difficult? And by changing material to something that absorbes less heat the shot temperature should be more stable?

September 11th, 2022, 2:04 pm

Anyone figured out an idea to conveniently heat up the stone or replace it with an insulating material?

Take a door hole saw and cut out the appropriate diameter from an old plastic cutting board (PTFE). Then take a belt sander and sand it down to the right height. This is how to make your own scace device with a blind filter basket.

#43: Post by **nisb** » September 11th, 2022, 2:54 pm

Tjyven wrote:Do I understand correct that the stone absorbes heat making the thermal control of the shot difficult? And by changing material to something that absorbes less heat the shot temperature should be more stable?

Yes - I'm guessing the stone is a leftover from previous versions of the machine without active heating.

vecchi della seattle wrote:Take a door hole saw and cut out the appropriate diameter from an old plastic cutting board (PTFE). Then take a belt sander and sand it down to the right height. This is how to make your own scace device with a blind filter basket.

Most cutting boards are HPDE (high end ones may be POM), but HPDE is sufficiently temperature resistive, food grade and with a thermal conductivity that is about 1/10 of stone. I'd still worry though, like if using EPS, about leakage from the plastic.

I put in some pellets of activated charcoal that I had laying around, and noticed an improvement: Rather unscientifically, a shot pulled at 96C with 1x pre-heating flush tasted bitter where the same coffee and temperature with the stone and 5x pre-heating did not.

#44: Post by **nisb** » September 11th, 2022, 3:52 pm

Heck, I speculate that small pebbles would be an improvement over the stone. While the thermal characteristics are the same the larger surface area would mean that they heat up quickly (probably in one flush). Somehow, pebbles feel right given the rough, utilitarian nature of the machine.

#45: Post by **Tjyven** » September 12th, 2022, 10:04 am

What shot size do you get if you just remove the stone?

September 28th, 2022, 2:50 am

nisb wrote:...

One thing that strikes me as downright odd: The shower screen is a IMS E61 screen that is held in place by the group head gasket squeezing against the side walls of the group head. The piston from the lever ends above the top edge of gasket/shower screen, and as such the 'cup' formed by the shower screen would be full of water at the end of the shot - had the maker not placed a stone (!) inside the shower screen (see image).

image

Now in this position the stone is not heated by the boiler, and this makes thermal management very difficult - something that should be very easy with a PID controlled open boiler lever. If I take it out then I'm struggling to get sufficient shot volume and the water accumulating in the shower screen cavity makes the machine messy.
...

Did anyone talk to the factory if they are planning to change this error in construction that the stone is?

September 29th, 2022, 6:43 am

Maolo wrote:image
image
image
image

I saw the pictures you posted and I am wondering if your machine has the same stone in the shower screen that is mentioned to n the above linked post.

Also what is your maximum shot volume in the cup for your typical dose, e.g. 18g coffee in, 70ml out max. I don't mean what ratio you typically use but what the limitation of the volume is given a fixed amount of coffee in the basket.

I am currently talking to Jiaozuo Double Eagle Machinery CO.Ltd about the machine they sell and they claim it doesn't have the stone. I am still not sure if that means they have a better construction or if they just have a big area that needs to be filled with water on every shot.
Where did you buy the machine?

September 29th, 2022, 7:42 am

nisb wrote:I just received my jian yi and 5 shots in I'm enjoying it a lot. It's clearly not a refined product, there are several cosmetic issues (e.g. dings and scratches right out of the box) and safety issues (temperature sensor hanging on a wire and may pop out of open boiler when lifting the lever to pull a shot, causing the heating element to stay on until turned off by user (no timer)).

One thing that strikes me as downright odd: The shower screen is a IMS E61 screen that is held in place by the group head gasket squeezing against the side walls of the group head. The piston from the lever ends above the top edge of gasket/shower screen, and as such the 'cup' formed by the shower screen would be full of water at the end of the shot - had the maker not placed a stone (!) inside the shower screen (see image).

image

Now in this position the stone is not heated by the boiler, and this makes thermal management very difficult - something that should be very easy with a PID controlled open boiler lever. If I take it out then I'm struggling to get sufficient shot volume and the water accumulating in the shower screen cavity makes the machine messy.

Anyone figured out an idea to conveniently heat up the stone or replace it with an insulating material? Something like styrofoam would be functionally better but I'd be worried about what it would leak into the coffee. I've also considered activated charcoal, which I have laying around (food safe and hydrophobic)

Would you be so kind to take a picture of the cylinder without the shower screen. So that I can understand how it is constructed there.
It could be possible that the piston could move where the stone is once the stone is removed, but we will see on the picture if you take one

September 29th, 2022, 7:44 am

Tjyven wrote:Still waiting for my machine so cant help you but guess I will have the same issue soon then. Do I understand correct that the stone absorbes heat making the thermal control of the shot difficult? And by changing material to something that absorbes less heat the shot temperature should be more stable?

Did you receive your machine yet?
Is there a stone in it?
Where did you buy it?

September 29th, 2022, 7:52 am

nisb wrote:Yes - I'm guessing the stone is a leftover from previous versions of the machine without active heating.
...

In a post on page 1 it is mentioned that the stone wasn't there for version 1. I would hope that one could remove the stone and change the rod connecting the lever and the piston so that the piston can move down where the stone is once removed.

pham wrote:...

Funny side note: the newer versions came with a stone inside of the machine. Like, a literal rock. We all were trying to figure it out what it was for for half an hour, but we realized it was for remineralizing water! The only two real downsides I can see with this machine is the bulkiness/lack of aesthetic appeal, as well as the availability. It's a lot sketchier to get one of these than a F58.

PS: sorry for posting so many messages at once. I just want this to work so badly. Anyone know if the tabao link on the first page is really produced by someone else or maybe Double Eagle was the factory for all versions?