Ultimaker 2+ not moving to front of buildplate.

[Rharman8 0]

Hi All.

My 2+ has been working perfectly for the last 3 years. Moderate use - 1150 hours.

Suddenly it is making a grinding noise - just at the start of the print and not moving to the start position at the front of the build plate.

It then starts printing normally but at the back of the build plate. Unless its a very small object, it wants to print off the back edge.

I have checked the belt tension and the gear wheels? and all seems OK.

Possibly needs a belt replacement? Any advice / suggestions welcome.

Video attached.

 

[IRobertI 521]

Can you move the print head freely by hand (with the machine turned off)?

 

What happens if you move the print head to the front center of the print volume and then start a print?

[gr5 2,265]

Check the friction front to back (Y axis) versus left to right (x axis).  This could be excesss friction.

 

This behavior could be high friction.  But it could also be that one of the 4 wires to the stepper is broken.  Or the stepper driver could be broken (diagnose by swapping X and Y stepper cables).  The stepper itself is probably the least likely part to break.

[Rharman8 0]

On 3/29/2019 at 12:41 PM, IRobertI said:

Can you move the print head freely by hand (with the machine turned off)?

 

What happens if you move the print head to the front center of the print volume and then start a print?

 

Yes I can move it anywhere with the machine turned off.

I just tried moving it to the front canter and starting a print. The print head does the same as in the video above: it moves to the back left and "grinds" before starting the print right at the back of the buildplate.  

[gr5 2,265]

Please show another video of it happening when the head starts at the front center as this sounds different now.

 

There is a "loud grinding" issue during homing the head when the limit switch does not get hit but your issue seems much gentler/quieter than what I'm used to.  More like the stepper is too weak to move.

 

One possibility is that the steps/mm is set too high and it's trying to move faster than possible (say 1 meter per second).  I'd try a "factory reset" which resets all the acceleration, max speed, and steps/mm values back to factory defaults.

[Rharman8 0]

https://www.youtube.com/watch?v=H2pRXqfgwVY&feature=youtu.be

 

I have checked the limit switch and it does seem to be working. Feels like the "trigger" part of the switch is a bit loose but the "click" is clearly audible.