Just do a regular calibration. Just hand tight the knobs, no force needed. Then start the calibration. Slowly rotate the knob until it the printer beeps. When the calibration is done. Print one of these that fits the bed thingiverse calibration
Carefully check the result. You should have a consistent print. If not, twist the knob closest to where you need to move re-calibrate. Thin line, the bed need to be closer to the nozzle, thick line that curls, move the bed away.
Note, when turning the knobs, just move it 1/4th turn each time. And make a note wich knob, the direction (clock wise or counter clock wise).

To get more info, search on youtube for flash forge finder calibration, there are a lot of videos there.

I bought Buildtak that I replaced the bed with. I don’t use glue. I did print out a couple of calibration figures that I downloaded from Thingiverse. After a couple of re-calibrations and printing with the calibration figures I have not touched the calibration again.
However, when I printed the MySensors box from Thingiverse the corners still lifted.
That was when I found the suggestion to print with a rim.
Now my prints never lift.
I also clean the bed after each print with IPA.

Print with a rim. There is a tickbox for it.

Yes, and I am very pleased with it.

@ahmedhodhod did it work with the suggested links?

eeprom write long

PLease, DON’T write to eeprom in the loop(), you will destroy the eeprom. The lifecycle for the eeprom is 100000 writes/read, after that it is destroyed.
info about eeprom writes at arduino

EDIT: With the current code (write to eeprom every second) the eeprom will be destroyed after aprox 69 days.

I don't know if it affecting your case, but according to the source code for the BH1750 library you need to set the mode:
Source code for bh1750 library
Note that the begin() function needs a mode parameter, and that is used in configure, it if is not provided it is an invalid mode,

void BH1750::begin(uint8_t mode) {

  Wire.begin();
  //write8(mode);
  configure(mode);
}


void BH1750::configure(uint8_t mode) {

    switch (mode) {
        case BH1750_CONTINUOUS_HIGH_RES_MODE:
        case BH1750_CONTINUOUS_HIGH_RES_MODE_2:
        case BH1750_CONTINUOUS_LOW_RES_MODE:
        case BH1750_ONE_TIME_HIGH_RES_MODE:
        case BH1750_ONE_TIME_HIGH_RES_MODE_2:
        case BH1750_ONE_TIME_LOW_RES_MODE:
            // apply a valid mode change
            write8(mode);
            _delay_ms(10);
            break;
        default:
            // Invalid measurement mode
            #if BH1750_DEBUG == 1
            Serial.println("Invalid measurement mode");
            #endif
            break;
    }
}```

@pepson said in RFM69 new driver delay:

And tell me how you have connected Gateway to RPI3? By ethernet or by serial ? Because i see in your building Gateway that you dont use parameter ETHERNET on port 5003

I use Ethernet to connect to my Domoticz.
The reason that you don't see my configuration for ETHERNET or PORT is because they are default when you configure.
If you look at the file Makefile.inc you will see the build options. In my case the file looks like this:

SOC=BCM2837
CPPFLAGS=-march=armv8-a+crc -mtune=cortex-a53 -mfpu=neon-fp-armv8 -mfloat-abi=hard -DMY_RADIO_RFM69 -DMY_RFM69_NEW_DRIVER -DMY_GATEWAY_LINUX -DMY_DEBUG -DLINUX_SPI_BCM -DLINUX_ARCH_RASPBERRYPI -DMY_RFM69_FREQUENCY=RFM69_868MHZ -DMY_IS_RFM69HW 
LDFLAGS=-pthread 
PREFIX=/usr/local
CC=gcc
CXX=g++
BUILDDIR=build
BINDIR=bin
GATEWAY_DIR=/usr/local/bin
INIT_SYSTEM=systemd
SPI_DRIVER=BCM

So in my case I have these defines:
MY_RADIO_RFM69
MY_RFM69_NEW_DRIVER
MY_GATEWAY_LINUX
MY_DEBUG
LINUX_SPI_BCM
LINUX_ARCH_RASPBERRYPI
MY_RFM69_FREQUENCY=RFM69_868MHZ
MY_IS_RFM69HW

This is my generic temperature/humidity/battery level sketch that I use. I have upgraded all my nodes and gateway to 2.3.0 yesterday and I don't have any issue whatsoever

/**
 * The MySensors Arduino library handles the wireless radio link and protocol
 * between your home built sensors/actuators and HA controller of choice.
 * The sensors forms a self healing radio network with optional repeaters. Each
 * repeater and gateway builds a routing tables in EEPROM which keeps track of the
 * network topology allowing messages to be routed to nodes.
 *
 * Created by Henrik Ekblad <henrik.ekblad@mysensors.org>
 * Copyright (C) 2013-2015 Sensnology AB
 * Full contributor list: https://github.com/mysensors/Arduino/graphs/contributors
 *
 * Documentation: http://www.mysensors.org
 * Support Forum: http://forum.mysensors.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 *******************************
 *
 * DESCRIPTION
 *
 * This is a sketch I use to measure temperature, humidity and battery level on
 * my Easy/Newbie PCB for MySensors (rev 9)
 * Hardware used:
 * Easy/Newbie PCB for MySensors
 * BME280 (I only use temperature and humidity, all code for barometic pressure removed)
 *
 */

// Enable debug prints to serial monitor
//#define MY_DEBUG
#define   MY_SPLASH_SCREEN_DISABLED  // This saves a couple of bytes
// Enable and select radio type attached
#define   MY_RADIO_RFM69
#define   MY_IS_RFM69HW
#define   MY_RFM69_NEW_DRIVER
#define   MY_RFM69_FREQUENCY RFM69_868MHZ

#include <MySensors.h>
#include <Wire.h>       // Enables the Wire communication protocol.
// Bosch BME280 Embedded Adventures MOD-1022 weather multi-sensor Arduino code, 
// written originally by Embedded Adventures. 
// https://github.com/embeddedadventures/BME280
#include <BME280_MOD-1022.h>
// Internal battery measurement https://github.com/Yveaux/arduino_vcc
#include <Vcc.h>

// Change all text variables here, no need to hunt them down in the sketch
// For sendSketchInfo()
#define SKETCH_NAME       "Generic Temeperature/Humidity"
#define SKETCH_VERSION    "1.13"
// For present()
#define PRESENT_TEMP_TEXT "Temperature Generic"
#define PRESENT_HUM_TEXT  "Humidity Generic"
#define PRESENT_BAT_TEXT  "Batteri Test-3"

// Battery measurements
const float VccMin        = 1.8*1.0;  // Min Vcc level, in Volts. Example for 2xAA Alkaline.
const float VccMax        = 2.0*1.5;  // Max Vcc level, in Volts. Example for 2xAA Alkaline.
const float VccCorrection = 1.0/1.0;  // Measured Vcc by multimeter divided by reported Vcc

Vcc vcc(VccCorrection);

// VARIABLES YOU CAN CHANGE
// Send temperature only if it has changed? 1 = Yes 0 = No.
#define COMPARE_TEMP 0
// Set this value to the minimum change in temperature to measure.
// BME280 has +-0.5 degrees precision, so it really doesn't matter that much.
float tempThreshold = 0.5;
// Send temperature only if changed? 1 = Yes 0 = No.
#define COMPARE_HUM 0
// Set this value to the minimum change in humidity to measure.
// BME280 has +-3% relative humidity precision, so it really doesn't matter that much.
float humThreshold = 0.5;

#define TEMP_CHILD_ID       1
#define HUM_CHILD_ID        2
#define VOLTAGE_CHILD_ID    3

float lastTemperature = -1;   // Store previous measurement
float lastHumidity =    -1;   // Stores the previous measurement
bool reportRSSI = false;      // true = send RSSI to controller
int sendBattery = 6;          // report battery level only after 6 loops = 6*4 minutes = 24 minutes
// Placeholder for batteryloop, set to one above sendBattery so that we get a report on startup
int batteryLoop = sendBattery + 1; 

// Time between send (in milliseconds), in this case, 4 minutes.
unsigned long FOUR_MINUTE_SEND_FREQUENCY = 4 * 60000;

// MYSENSORS COMMUNICATION VARIABLES
MyMessage temperatureMsg(TEMP_CHILD_ID, V_TEMP);
MyMessage humidityMsg(HUM_CHILD_ID, V_HUM);
MyMessage voltageMsg(VOLTAGE_CHILD_ID, V_VOLTAGE);

void setup()
{

#ifdef MY_DEBUG
  Serial.begin(115200);
#endif

  Wire.begin(); // For the BME280 sensor
#ifdef MY_DEBUG
  Serial.println(F("Starting ..."));
#endif
}

void presentation()
{
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo(SKETCH_NAME, SKETCH_VERSION);
  // Present the sensors to the gateway and controller
  present(TEMP_CHILD_ID, S_TEMP, PRESENT_TEMP_TEXT);
  present(HUM_CHILD_ID, S_HUM, PRESENT_HUM_TEXT);
  present(VOLTAGE_CHILD_ID, S_MULTIMETER, PRESENT_BAT_TEXT);
}

void loop()
{
#ifdef MY_DEBUG
  Serial.println(F("Read BME280 and report it's values."));
#endif
  GetTemperatureHumidity();                 // Get temperature and humidity

  if(batteryLoop > sendBattery) {           // Is the batteryLoop higher than sendBattery?
#ifdef MY_DEBUG
    Serial.println(F("Read the battery voltage and report it."));
#endif
    MeasureBattery();                      // Measure and report battery level
    batteryLoop = 0;                       // Reset batteryLoop count
}
#ifdef MY_DEBUG
  Serial.print(F("Go to sleep for: "));
  Serial.print(FOUR_MINUTE_SEND_FREQUENCY / 60000);
  Serial.println(F(" minutes."));
#endif
  batteryLoop++;                           // Increase batteryLoop before we sleep. 
  sleep(FOUR_MINUTE_SEND_FREQUENCY);       // Sleep for 4 minutes
}

/************************************************
* GetTemperatureHumidity()
* Routine for measuring temperature and humidity
* Generic one that fits my need 
************************************************/
void GetTemperatureHumidity()
{
#ifdef MY_DEBUG
  Serial.println("");
  Serial.println(F("BME280 - Requesting new data from sensor module."));
#endif
  BME280.readCompensationParams();            // Need to read the NVM compensation parameters.
  // Normal mode for regular automatic samples
  BME280.writeStandbyTime(tsb_0p5ms);         // tsb = 0.5ms
  BME280.writeFilterCoefficient(fc_16);       // IIR Filter coefficient 16
  BME280.writeOversamplingPressure(os16x);    // pressure x16
  BME280.writeOversamplingTemperature(os8x);  // temperature x8
  BME280.writeOversamplingHumidity(os8x);     // humidity x8
  BME280.writeMode(smNormal);
    
#ifdef MY_DEBUG
  Serial.println(F("Getting new values"));
#endif
  while (BME280.isMeasuring()) {              // Wait for BME280 to fininsh reading data
#ifdef MY_DEBUG
    Serial.println("Measuring...");
#endif
    delay(50);
  }
  Serial.println("Done!");
  // Read out the data - must do this before calling the getxxxxx routines
  BME280.readMeasurements();
  float temperature = BME280.getTemperatureMostAccurate();  // Get the temperature first.
  float humidity = BME280.getHumidityMostAccurate();        // Get the humidity.
#ifdef MY_DEBUG
  Serial.print(F("BME280 - Temperature = "));
  Serial.print(temperature);
  Serial.println(" °C");
  Serial.print(F("BME280 - Humidity = "));
  Serial.print(humidity);
  Serial.println(F(" %"));
#endif
  // Now, let's send the measurements to the gateway.
  // Send temperature if the temperature difference bigger than the threshold
  if (COMPARE_TEMP == 1 && abs(temperature - lastTemperature) < tempThreshold) { 
#ifdef MY_DEBUG
    Serial.print(temperature - lastTemperature);
    Serial.println(F(" Temperature difference too small, don't send it to gateway."));
#endif
  } else {
#ifdef MY_DEBUG
      Serial.println(F("Sending new temperature to the gateway."));
#endif
      send(temperatureMsg.set(temperature, 1));
      lastTemperature = temperature; // Save temperatures for compare in the next round.
  } 
  // Send humidity if the humidity difference is bigger than the threshold.
  if (COMPARE_TEMP == 1 && abs(humidity - lastHumidity) < humThreshold) { 
#ifdef MY_DEBUG
    Serial.print(humidity - lastHumidity);
    Serial.println(F(" Humidity difference too small, don't send it to the gateway."));
#endif
  } else {
#ifdef MY_DEBUG
    Serial.println(F("BME280 - Sending the new humidity to the gateway."));
#endif
    send(humidityMsg.set(humidity, 1));
    lastHumidity = humidity; // Save new humidity to be able to compare in the next round.
  }
#ifdef MY_DEBUG
  Serial.println(F("BME280 - Measurement complete. Putting sensor to sleep."));
#endif
  BME280.writeMode(smSleep);  // set the BME280to sleep mode, save battery
} // End of GetTemperatureHumidity

/*
* MeasureBattery()
* Routine for measuring battery level
* Generic one that fits my need
* NOTE: You need to calibrate the measurement to get correct readings
*/
void MeasureBattery()
{
  float Vbat = vcc.Read_Volts();
  int batteryPercent = static_cast<int>(vcc.Read_Perc(VccMin, VccMax));

#ifdef MY_DEBUG
  Serial.print(F("Battery percent: ")); 
  Serial.print(batteryPercent); 
  Serial.println(" %"); 
  Serial.print(F("Battery Voltage: ")); 
  Serial.print(Vbat); 
  Serial.println(F(" Volts"));
#endif
    sendBatteryLevel(batteryPercent);
    send(voltageMsg.set(Vbat,2)); //send battery in Volt 2 decimal places
}