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Bed Levelling Failed. Sensor didn't trigger  

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Jeff
 Jeff
(@jeff-2)
Eminent Member
Bed Levelling Failed. Sensor didn't trigger

Recently finished the upgrade of Mk3 to Mk3 S.  After running the calibration wizard and everything checks out fine, I run a print to set Live Z.

I always have to run a second print to get closer, but if I start the 2nd print, the printer either goes to the far positive X and drives the hotend into the sheet with the error message "Bed Levelling Failed.  Sensor didn't trigger.  Debris on nozzle?  Waiting for reset." (image attached)

If I re-run the wizard and calibrate again, the printer is OK for one print, try to run a 2nd and get the same message.

Crash stat shows 1 failure in the X

I ran a different print later, and after about 2 or 3 hours, the printer seemed to have shifted to positive X, where part of the print was hanging off the side of the print.  What could cause this?  I saw another thread which may have the answer and will look at it after posting this.

Posted : 17/12/2019 4:07 am
JoanTabb
(@joantabb)
Moderator
RE: Bed Levelling Failed. Sensor didn't trigger

Is the X axis Homing properly? if the X axis is failing to home properly, then the last expected sense point can end up with the PINDA, beyond the edge of the Build plate, where it WILL NOT sense the build plate...  |

so check for resistance when moving the X axis by hand, 

the problem may be as simple as lack of lubrication on the linear bearings, overtightened back plate on the X axis assembly (putting pressure on the Linear bearings)   or an overtightened idler wheel mounting bolt.

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 17/12/2019 10:41 am
Jeff
 Jeff
(@jeff-2)
Eminent Member
Topic starter answered:
RE: Bed Levelling Failed. Sensor didn't trigger

Thank you Joan.  Using the live Z test g-code it has gone past the right-hand side; last print it failed on the first point which would be 0,0 I think.

I'll clean oil the linear bearing rods and see about the idler bearing and backplate bolts.

Posted : 17/12/2019 1:26 pm
Jeff
 Jeff
(@jeff-2)
Eminent Member
Topic starter answered:
RE: Bed Levelling Failed. Sensor didn't trigger

I cleaned and oiled the X-axis rods, made sure the backplate screws were not too tight (they are barely snug) and the X-axis stepper tensioner screw is loose.  The belt will squeeze together with very little force, and there does not seem to be any more resistance to moving the extruder head back and forth than moving the table forward and back.

Also, there is some black dust on the stepper side below the gear - is it possible the alignment between the driven gear, the extruder head and the idler is off?

I just went to auto-home, and the head went left-right table fore and aft, and the head up and down - and down and down.  Sensor failed to trigger and it pushed the nozzle into the bed and forced the bed down a bit.  Could the PINDA be bad - and how to test if it is?

This post was modified 2 years ago by Jeff
Posted : 22/12/2019 9:27 pm
Jeff
 Jeff
(@jeff-2)
Eminent Member
Topic starter answered:
RE: Bed Levelling Failed. Sensor didn't trigger

Now it won't even calibrate.  It starts the calibration OK, the fan self-tests, does the X (although it chattered a bit when first moving the X), the Y and then on Z it is driven down to the bed and gives the sensor failed to trigger message.  I am at wit's end, I have no idea what is wrong.  The PINDA is set to the thickness of the zip-tie from the bed without the steel sheet.

Right now, I have an $800 desk ornament 🙁

Posted : 26/12/2019 2:26 pm
towlerg
(@towlerg)
Noble Member
RE: Bed Levelling Failed. Sensor didn't trigger

"The PINDA is set to the thickness of the zip-tie from the bed without the steel sheet."

May be wrong (not have a particularly auspicious day and we've probably lost the first test) have you tried it with steel sheet.

Posted : 26/12/2019 3:26 pm
Jeff
 Jeff
(@jeff-2)
Eminent Member
Topic starter answered:
RE: Bed Levelling Failed. Sensor didn't trigger

@towlerg

Yes, I have, it did not make any difference.  But have not tried resetting with the steel sheet since the auto-home failure

Posted : 26/12/2019 4:09 pm
JoanTabb
(@joantabb)
Moderator
RE: Bed Levelling Failed. Sensor didn't trigger

@jeffrey-w4

with the extruder say 60mm above the build plate and the printer on but idle, presemting metal to the Pinda should make the LEDilluminate, and the pinda status should change on the LCD

 

regards Joan

 

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 26/12/2019 7:47 pm
Jeff
 Jeff
(@jeff-2)
Eminent Member
Topic starter answered:
RE: Bed Levelling Failed. Sensor didn't trigger

What does the LED status look like?  I have never noticed it.

Posted : 26/12/2019 7:54 pm
JoanTabb
(@joantabb)
Moderator
RE: Bed Levelling Failed. Sensor didn't trigger

@jeffrey-w4

Red colour showing through transparent resin around the cable entry into pinda body!

 

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 26/12/2019 7:58 pm
Jeff
 Jeff
(@jeff-2)
Eminent Member
Topic starter answered:
RE: Bed Levelling Failed. Sensor didn't trigger

OK - that is on all the time until I get a piece of metal about 1MM (it looks to be about the thickness of the zip tie) away from it.

What can be causing the sensor to not trigger, driving the Z-axis down to the bed?

Posted : 26/12/2019 8:47 pm
JoanTabb
(@joantabb)
Moderator
RE: Bed Levelling Failed. Sensor didn't trigger

@jeffrey-w4

Does the Pinda Status also change on the LCD Display,?

you can get a situation where the Pinda cable breaks and whilst the pinda still works, the signal does not get back to the einsy. because of the broken wire in the Pinda Cable

there are 4 wires, 
+5volts,
Ground,
Signal, & 
Thermistor,

if the signal wire breaks the pinda still has power so the LED will still work, but the printer won't see the status changes!

of course if the Pinda is too high, the same thing can happenn because the nozzle hits the build plate because the pinda is too high to sense the buildplate!

 

regards Joan

 

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 27/12/2019 9:40 am
Jeff
 Jeff
(@jeff-2)
Eminent Member
Topic starter answered:
RE: Bed Levelling Failed. Sensor didn't trigger

Where is the PINDA status on the LCD?  I scrolled thru all the menus yesterday and nothing stood out.

Posted : 27/12/2019 2:13 pm
JoanTabb
(@joantabb)
Moderator
RE: Bed Levelling Failed. Sensor didn't trigger

@jeffrey-w4

Hi Jeffrey, 

I am away from my printer at the moment. 

I think there is a 'Status' menu,  but I can't check, 
Hopefully somebody else can pick this up! 

 

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 27/12/2019 5:49 pm
jwvaughn
(@jwvaughn)
Estimable Member
RE: Bed Levelling Failed. Sensor didn't trigger

@jeffrey-w4

It is under Support.  Scroll weay down to Sensor Info and PINDA status is first on the list.

Jerry

Posted : 27/12/2019 6:21 pm
Jeff
 Jeff
(@jeff-2)
Eminent Member
Topic starter answered:
RE: Bed Levelling Failed. Sensor didn't trigger

@jerry-v2

Thank you, Jerry and Joan

Posted : 27/12/2019 6:25 pm
JoanTabb
(@joantabb)
Moderator
RE: Bed Levelling Failed. Sensor didn't trigger

Thanks Gerry!

Good Luck Jeffery!  

Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 27/12/2019 7:35 pm
Jeff
 Jeff
(@jeff-2)
Eminent Member
Topic starter answered:
RE: Bed Levelling Failed. Sensor didn't trigger

@jerry-v2 @joantabb

The sensor was showing 0 until it got close to metal - and it turns out that somehow it was really high!  I lowered the extruder until there was just a very slight drag on a piece of paper and reset the PINDA.  Calibration went OK, but when I tried to run a print it kept wanting to unload and reload filament (filament sensor ON) Finally turned the printer off, restarted and started the print again - and got the sensor failed error again. 

Calibrated again OK, started the print and so far - 2 hours in - it's OK.  Time will tell, I guess

 

Posted : 27/12/2019 9:47 pm
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