Hi,

as promised in Assaf's Chimera Mod Thread here some details about adapting his mod to the LMLM.

First of all most credits go to Assaf and a lot of other people here in the forum. They inspired me a lot with the modding and improvement activities and gave me the right hints and support to get at the end a really successful and well working espresso machine which has all features the pro machines have.

With these modifications I would say - if the coffee doesn't taste good it is definitely not the issue of the machine

As name I adapted Assaf's "Chimera" and called it for the LMLM "Chiara".

Following modifications I did:

• - Gear Pump
  - Pressure Sensor
  - Digital Temperature Control
  - Flow Sensor
  - FLB Unit
  - "Real" Paddle activation
  - Hidden Push buttons for 1cup, 2cup automatic mode
  - Info Display
  - Wifi Webinterface

To my surprise after 3 months of implementation the first shot was amazingly good (probably just luck, but it shows the potential of the new features).

First of all, here some pictures of the mod:








Cheers,

Tobias

That is impressive. Love the Chiara name and the fader control! And the 3d print (how is the PLA holding up in the heat?)!

Is that a display in the paddle?

BTW - Did you consider using a hall effect device for the potentiometer?

Edit - and the amazing quality build. It is almost hard to know where the upgrades were.

Bill of Material:

Controller:
- Arduino Mega (main controller)
- ESP8266 Wemos D1 (Wifi Module, Firmware uploads to Arduino)

Flowsensor:
- Digmesa Flowsensor 9NB-0100/01A

Pump:
- Gear pump MG304 Fluidotech
- Pololu VNH5019 Pump controller

Pressure sensor:
- Huba Control Pressure sensor 510.931S04050 5V

FLB:
- SWAGELOK METERING VALVE SS-4MG-MH
- ACL E206BV252/2 SOL VALVE 1/4"BSP FKM N. O + COIL E5 27W ACL 24VDC

Display:
- SSD1306

Temperature control:
- Si8641BC (for isolation)
- MCP4161(Digital Pot.)
- DS18B20

Paddle and Pushbuttons:
- Slider Potentiometer
- ADS1115 ADC for better and more stable analogue resolution
- Capacitive touch sensors
- 3D printed and acetone smoothened ABS case

Sensor Pumpfill:
- 1-Bit AC 220V Optocoupler Isolation Module Voltage


Power Supply:
- 24V DC
- 5V 3A DC DC Step Down Buck Converter Adapter

Pipes and Fittings:
- Stainless steel pipes (I prefer them meanwhile over copper - however copper will also do)
- Zoo of various fittings (BPT,NPT,Compression, etc.)

Crazy build Tobias

Here is my gear pump bracket


I'm planning a bracket for the electronics, hope to get it laser cut soon

Cheers

AssafL wrote:That is impressive. Love the Chiara name and the fader control! And the 3d print (how is the PLA holding up in the heat?)!

Is that a display in the paddle?

BTW - Did you consider using a hall effect device for the potentiometer?

Edit - and the amazing quality build. It is almost hard to know where the upgrades were.

Yep, heat might be a problem for the 3D printed paddle panel. Therefore I went for ABS instead of PLA.
ABS has the other advantage that it can be smoothened with acetone (for all who try this - be very careful with this, as it can be highly explosive..).

And correct, I put the small display in the paddle case. Actually I show there only basic information like
- seconds preinfusion
- seconds draw
- temperature selected
- some status things

All other more complex things I plan to put later in a web interface with all the neat things like graphs and so on..

Hall Effect? Didn't considered yet - what is the advantage? Main issue might be the heat in close to the boiler - I hope the slider poti will last some time in a 100°C environment ...

febi wrote:Crazy build Tobias

Here is my gear pump bracket

I'm planning a bracket for the electronics, hope to get it laser cut soon

Wow Febi, looks excellent the FG304-Pump. Saves a lot of space.
I considered this as well, but it was bit too expensive compared to the MG304.
And laser cutting I'm still dreaming of ...

Tobias, your Chiara mod is very cool! I'm dying to see more!!

Very clean and impressive!

Tobias007 wrote:Hall Effect? Didn't considered yet - what is the advantage? Main issue might be the heat in close to the boiler - I hope the slider poti will last some time in a 100°C environment ...

Actually silicon is much more resilient to heat than the plastic wiper in a linear fader. Likely these are rated to 70C but maybe 50C for actual use. The first problem would probably be lubricant drying out. That may cause the control to stutter (sort of like the volume pot in old amplifiers which creates noises and pops).

Craig sells a fader lube that seems to work well.

Some Hall effect sensors have a linear output depending on the magnetic field. So you'd mount a magnet on the wiper and the sensor somewhere where it gets closer to the sensor and the voltage goes up (or down). It will take some time to find the right sensor and locations for it and the magnet.

Some even have magnets that are oriented on their axis. So that you can hide a magnet in the pivot and the sensor above it and it outputs a quadrant signal (or PWM to rotation).

Hi,

got bit further with the modifications. Meanwhile the ESP32 is running fine. Saves me some level converters and provides Wifi/Bluetooth support within the same environment. However still lot to do to make it 100% stable...



The temperature control is awesome. The DS18B20 does its job and provides me more control over temperature (still not so happy with its position on top of the brewhead - but it provides with certain delay good values. Position inside the brewhead would be much better (in a stainless steel tube) .. but too much effort for this...

I replaced the poti/96 degree dial with a 3D-printed one plus a rotary switch. With each tick it changes the temperature per 0.1 degree up/down.





Cheers, Tobias