Nozzle hitting bed during the bed calibration process

Above link contains the issue video and images for reference.

Hello everyone and thank you for helping me out.

We have been using our A350T 2.0 since April 2022 and in the past year along with other accessories, we also purchased a Dual extrusion module.
So we have been using the stock 3D printing and Dual extrusion head alternatively and having a quick swap kit makes this change very fluent.

We have recently faced an issue with the bed calibration process for the stock 3D printing module.
what exactly happens is that,

  1. Once I start the machine with the stock 3D print head attached the machine goes for auto-bed calibration.
  2. During the calibration process the sensor cannot sense the bed proximity which in turn causes the nozzle to press down on the bed very hard.
  3. This pressing is so hard that the PEI sheet flexes which we can visually observe.
  4. The calibration process video and the 3D print head images have been uploaded for reference.

To inform you further,

  1. We have been using the dual extrusion head without any issues there is no trouble with the calibration process for this module.
  2. Also we have been printing long hours of models with it.

To resolve this we tried updating the firmware and also to do a manual calibration while starting with the stock 3D print head but we could not enter the menu and select other options once the machine starts with the stock 3D print head attached.

We only have one option which is to perform auto-bed levelling during which the nozzle presses hard against the bed.
Awaiting help.
Thanks & Regards,
ADVENGEO

You need to check the sensor for proper operation, and if it is faulty, then contact Support for replacement.

1 Like

what mxbrnr says. you are describing a faulty sensor or adjustment thereof.

first, is your sensor working at all…take your spatula and place it under the sensor if the red light comes on as the spatula nears the sensor then the sensor is working and you should look at adjusting the z height of it (screw on back in slot different then the others).

no light means the sensor is broken and needs replacing

Thanks a lot for simplifying it further,

But the issue is that as soon as I turn on the machine the first pop-up menu is of bed calibration.
So how do you check it before?

Are you suggesting simply placing a steel spatula below the nozzle and observing the module’s red light blink? irrespective of what appears on the display and whether I select any option or not.
Is my interpretation correct about your suggestion?

Appreciate your time.

yes. to check for the sensor ability to see metal. 1. turn on machine. 2. place spatula under sensor and see if it turns on led. if yes then you can try adjustment.

from your video i think your sensor is too high. it should be about a business card thick above the nozzle. ie with the nozzle touching the bed, the sensor should be slid down to rest on a business card then tightened. that should get you close. in my case the bottom of the sensor(near the bed) is 8mm-8.4mm below the bottom of the housing