The CR Touch/BLTouch is an automatic bed leveling system that helps home the Z-axis with the aid of its probe. This makes printing easier by providing a mesh for leveling the bed before printing.
However, it can’t perform this function if it doesn’t home first. Here are some of the issues that can stop it from homing.
- Faulty wiring
- Loose connections
- Wrong firmware
- Poorly configured firmware
- Connected Z limit switch
Here’s how to fix the CR Touch not homing properly:
- Check the CR Touch’s wiring
- Check the CR Touch’s plugs
- Flash the right firmware
- Configure your firmware properly
- Disconnect the Z limit switch
1. Check The CR Touch’s Wiring
If the CR Touch constantly flashes red without homing the bed, something might be wrong with the wiring. To fix this, you will have to remove the faulty wire and replace it.
One user had his BLTouch constantly working without homing which is similar to the CR Touch. It turned out that they had a fault within the BLTouch wiring.
They had to replace the wire to address the issue. You can check your BLTouch’s wire with a multimeter to check for errors.
2. Check The CR Touch’s Plugs
For the CR Touch to work correctly, it must be plugged in all the way on your motherboard. If the connection is shaky, the CR Touch won’t work correctly.
You can see an example of this issue in the video below. The X and Y axes homed properly, while the Z-axis refused to home.
You can fix this issue by properly plugging in the CR Touch’s wires. Also, ensure the wires are plugged into the proper ports on the board.
Remember, the ports are different on 8-bit and 32-bit machines.
3. Flash The Right Firmware
If you’re installing a CR Touch or BLTouch system, you’ll have to flash the right firmware with the printer before you can use it. Most people often make the mistake of flashing the wrong firmware, which can brick the printer.
Before flashing the firmware, you first have to note down the version of your board. Next, you’ll have to go to the manufacturer’s website and download the correct version of your firmware for flashing.
You can find them here.
You can also try using alternative firmware builds like Jyers or Marlin. You have way more customization options, and they are easier to use.
4. Make Sure You Configure Your Firmware Properly
Configuring your firmware properly in the Config.h files is necessary for the CR Touch or BLTouch firmware to work. Some users go for third-party firmware from other providers like Marlin or Jyers.
You will have to modify the configuration settings to use this firmware with ABLs like BLTouch or CR Touch. Most users forget to do this, resulting in printing errors.
One user forgot to compile the line that activates the CR-Touch:
disable #define USE_ZMIN_PLUG – this is because it is not being used with their 5-pin probe.
Some people have experienced issues due to not setting the correct pin for the sensor input in the firmware.
Another user also forgot to set the BL Touch inverting to false in the firmware. The errors are countless.
So, if you are installing custom firmware, make sure you follow the provided instructions to the letter.
5. Disconnect The Z Limit Switch
After installing an Automatic Bed Levelling system like the CR Touch, you should disconnect your Z limit switch. If you leave the Z limit switch plugged in, it can interfere with the CR Touch resulting in homing failure.
So, disconnect the Z limit switch from the motherboard.
That’s all you need to know about resolving homing errors on the Ender 3 or any other printer. Just remember to always check the wiring first.