Weird cracking sound at the start of printing

[ibnul21 0]

My ultimaker 3 extended is making a cracking sound right at the start of printing. I have a video of it in the following link:

 

https://drive.google.com/file/d/18QAjhxYC2Xy78odw2MmHF-RyHaRjvn3W/view?usp=sharing

 

Any help would be really appreciated.

 

Cheers,

Ibnul.

[Torgeir 242]

Hi @ibnul21,

 

Welcome in here.

 

There is two issues that can make this ratteling noise, but the noise always come from one of the stepper motors.

The noise is made as the stepper cant move anymore, like hitting a wall and continue until it is "synchronized"..

Happen if the friction is too high or current is too low, in both situations the stepper makes noise.

As there is 6 shafts involved during extruder movement around the bed, thous shafts need lubrication to keep friction as lo as possible. This is number one for such problem, -so periodical lubrication of thous shaft's is important.

 

You might have another problem, as this seems to occur when homing before start of movement.

In your case, it might be the X home switch that is mounted too close to the hard stop, meaning the stepper have a little too short stoppage distance for deceleration. So the last two or three step is done against the full (hard) stop and making this noise.

This might have happened if the switch have become worn, allowing to move further, -or slightly become loose over the time, also allowing the head further (closer to the hard stop).

Adjusting this switch a little more "from" the wall it's traveling toward might fix this problem.

Note: To me it looks like it is the X stop switch, but might either be the Y switch..

This might be easier to see/observe from above.

(If the screws for the micro switch are loose, be careful -do not to over tightening the two small attaching screws.)

 

Good luck

Thanks

Torgeir

[ibnul21 0]

Hi,

 

I have tried to manually adjusting both the switches so that it stops early but that doesn't see to work. On top of that I have noticed that the starting point of the print has also changed both is X&Y direction. Is there a way to reset the starting point?

 

Cheers!

[robinmdh 100]

it could be the Z is moving past the home point, please also check the Z end switch in the center of the botom panel on the UM3(E), if anything got stuck in there it could explain this maybe.

 

Changing the starting point can be done by using G92 command in the start of your G code first do G0 X0 Y0 then A G92 X1 Y-1 or something to undo 1 mm of bending outward. you can edit this in machine settings in cura I believe.

[Torgeir 242]

Hi @ibnul21,

 

I'll think @robinmdh is right here, as if you do a start sequence all axes are synchronized including the height (Z).

So here, -a head homing would have confirmed this I'll think..

Also when you move the switches the start position will slightly change.

 

As the bed may slowly slide down, it tend to rest on the Z switch and signal down limit is active. So this switch signal stepper to move up a bit and then move down again to synchronize the Z axis.

You did not confirm that the shafts are lubricated, -this is the most common reason for making stepper noise.

There's two parallel "Z axis" sliding shafts, need frequent oiling and the stepper Z axe need frequent greasing..

Sure I'd assume you did, -but just wanted to mention this important point again.

 

If you think your head homing point have moved too much, -it's possible to revert the adjustment one by one -using the "home head" function. 

Also, for checking the "home bed" function, you might lower the bed or lift then lower the bed.

 

Good luck

Torgeir

 

 

 

 

 

[ibnul21 0]

Hi all. Thanks for your suggestion. Let me try em out. Cheers!