An external disturbance was detected on force sensor 2 (fixed!)

Bambu Lab X1 Series Bambu Lab X1C
1

I’ve had a X1C from launch and had zero issues (besides user error) with it. I do regular maintanance as described in the Wiki.

I do have a replacement hotend and nozzle (Panda Revo and Diamondback Revo 0.6) which has performed ok.

But the last few weeks I am experiencing all kinds of issues:

  1. Bed levelling failed
  2. Build plate not being detected half of the time
  3. The following message appears 80% of the time:"AN EXTERNAL DISTURBANCE WWAS DETECTED ON FORCE SENSOR 2. THE HEATBED PLATE MAY HAVE TOUCHED SOMETHING OUTSIDE OF THE HEATBED. 90300-0b00-0001-0004-1053240

I’ve followed all the instructions in the Wiki and this hasn’t solved anything. I am slowly getting a bit desperate, because I can’t pinpoint the cause here and if I don’t know what it is it can’t be fixed.

Any suggestions or help?

2

Look at the guide bearings on either side in the front. Are they flush with their housings?

3 Likes
3

Hi John,

Thanks for the response. Yes, they are flush. That was also one of the suggestions in the Wiki. I also cleaned and lubricated all of the rods again. Triple checked there was nothing stuck or filament waste somewhere.

Any other suggestions or maybe a test path, so I can rule out errors?

1 Like
4

How does the Z belt look under the printer? I wonder if it is slipping or binding, causing the Z axis to not be where the printer expects it.

5

Z belt, and possible replacement. You might be having faulty sensor under heatbed.

Any prints failed?

6

Good afternoon,

The z-belt under the printer is the belt you see on the bottom of the printer, right?

Turning it by hand works flawelessly, but there is one very odd wheel that has damage.

x1c
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This looks very odd to me. Could that be the issue and how easy is that to be replaced?

EDIT: Just to make sure i’ve ordered a z-belt and the thing that looks broken. Maybe that will fix it

7

Also: Every 5-6seconds a red light is flashing behind the poopchute. I’ve never noticed that before, but I am wondering if that is normal or not. NB: I managed to take a photo while it flashed:

x1c2
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8

Update 2/8/2024 :
I’ve received and exchanged the Z Belt and the pulley. No improvement and still occasionally receiving the same error.

I’ve also ordered and installed an original hotend and this also doesnt solve my issue.

Im slowly but surely getting more and more frustrated. what else can I do?
At this moment I have an unreliable expensive piece of junk at home. Creating a ticket doesnt work because that stupid process asks for a log and you cant submit a ticket without a log.

@bambulab : a bit of support here would be appreciated

9

Sorry you’re having such trouble. I’d stick with the ticket. I had an extruder blow up and while the process was a little cumbersome and annoying, I did get a new extruder sent to me relatively quickly after I went through the process.

10

As an experienced mechanic, I have encountered various mechanical problems over the years. A common issue is related to an incorrect position of the platform support, which can cause the machine to stop due to mechanical overload and overcurrent.

Here are the steps I would follow to diagnose and solve this problem:

Diagnostic and Repair Steps:

  1. Safety First:
  • Turn off the machine: Ensure that the machine is powered off and disconnected from the electrical supply to avoid any risk of electrocution.
  1. Disconnect the Stepper Motor:
  • Unplug the stepper motor: Identify the power connector for the stepper motor. Carefully disconnect it, noting its position and orientation to facilitate reconnection.
  1. Inspect the Connectors:
  • Check the condition of the plug: Visually inspect the power plug to ensure it is neither burnt nor melted. Replace it if necessary.
  1. Manual Check:
  • Manually turn the platform: Turn the platform by hand to assess if there is excessive resistance.
    • No resistance: If the movement is smooth, the problem could be a stepper motor that is drawing too much power.
    • Resistance detected: If you feel resistance, the platform is probably misaligned.
  1. Re-align the Platform:
  • Manually lower the platform: Lower the platform by hand to the bottom to ensure it is parallel to the base of the machine, using it as a reference for flatness.
  • Loosen the lead screws: Slightly loosen the three lead screws while keeping the platform level.
  • Tighten the lead screws: Retighten the three screws to secure the platform in the correct position.
  1. Final Test:
  • Manual verification after adjustment: Turn the platform by hand again to ensure the resistance is gone.
  • Reconnect the stepper motor: Reconnect the stepper motor and test with the electronics to verify proper operation.

Additional Precautions:

  • Avoid short circuits: Handle electrical connections with care to avoid short circuits that could damage the motor or the machine’s electronics.

By following these steps, you should be able to resolve the platform support positioning issue and restore the proper functioning of your machine.

11

Knock on wood, but my issues seem to be gone.

Where before I wasn’t able to print 2, maximum 3 prints without the error appearing I have printed 9!!! perfect prints now.
So what have I done so far:

  1. Replaced the Biqu REVO hotend with a fully assembled stock one (NOFIX)
  2. Checked all z rods and cleaned them (NOFIX)
  3. Replaced Z belt (NOFIX)
  4. Retightend the hotbed screws (NOFIX)
  5. Removed the backcover and cheched all cabling and cleaned z rod from there (NOFIX)
  6. Replaced pulley under printer (NOFIX)
  7. Alligned the printbed offset (NOFIX)

But then I found a video on Youtube from someone that had similar issues as I did. Since the explaination made sense to me (sometimes it threw the error sometimes it did), I’ve tried this solution.

I can’t believe it, but it seems it did the trick. And the trik was using a piece of tape.

Watch the video. Did actually looks like it fixed the issue.

6 Likes
12

JUst a small update: I’ve printed more than 10 models, multicolor, small, large without the error appearing. I consider the issues fixed.

I’ve also re-installed the Biqu Revo Hotend. This also doesn’t through the error. Therefore… Happy.

@BrotherC This might be som ething to bring back to your engineering department and have them fix this permanently in an updated version of the X1C

13

Currently testing this fix for myself. First print NO ISSUES. Whoop! Thanks all.

Did anyone else have a “void” sticker on the screw behind the AMS plugin on the back panel? I purchased my printer secondhand…so I’m not too worried about it, but I’d assume others might be…

14

Hi Joshua,

Welcome to the forum.

To answer your question: yes, the middle screw for me and some on the printbed for that matter, have a voidscrew (ministicker over the screw). Since I bought my X1C at launch my warranty is gone anyway.

15

What a lifesaver! I struggled with these errors for quite a while and after fixing the cable it didn’t occur again. Thank you so much for pointing me in the right direction!!