Fixing the belt (Ultimaker 2)

[eduardas-afanasjevas 0]

After my last print I noticed that one of the belts is sloppy (see picture http://imgur.com/Wl7fHRd)

I'm not sure what happened. I contacted Ultimaker support but didn't get a reply.

 

• Can I tighten the belt? If so, how can I do it?
  
• Alternatively, do I need to replace the belt? If so, how do I do the replacing?
  

Not sure how to proceed and avoid this in the future

 

[illuminarti 17]

The belt may have just skipped a few teeth on the pulley. Undo the grub screw on that pulley that you show in the photo, and let the pulley twist round until the tension on both sides is equalized, then tighten it up again.

 

[eduardas-afanasjevas 0]

It seems both sides are sloppy (see http://imgur.com/uGDYQt6).

Any way I can increase the tension?

 

[illuminarti 17]

There should be a spring tensioner inside the sliding block. I wonder if that has broken or come loose, or if the belt has just stretched?

Where are you located?

 

[illuminarti 17]

What about the tension on the other side of the sliding block? Is that really tight? You could try loosening both pulleys and trying to distribute the tension, but your photo gives the impression that there is just too much belt in play.

 

[eduardas-afanasjevas 0]

The belt was tight as it's supposed to be. However, all of a sudden it's much looser. I'm not sure where this extra belt lenght is coming from

 

[hieronymus 0]

The metal arm from the endstop looks awfully bent, did you do this yourself to correct some alignment issues?

If not, it probably means the whole carridge simply smashed into it without stopping the motor.

Could the continued running of the motor have streched the belt? (since the lower part of the belt is somewhat fixed inside that black slider-block, pulling on one side could make it longer?)

Not really sure, just putting it out there, I do agree with Illuminarti that the amount of play is quite substantial.

 

[eduardas-afanasjevas 0]

The metal arm from the endstop looks awfully bent, did you do this yourself to correct some alignment issues?

If not, it probably means the whole carridge simply smashed into it without stopping the motor.

Could the continued running of the motor have streched the belt? (since the lower part of the belt is somewhat fixed inside that black slider-block, pulling on one side could make it longer?)

Not really sure, just putting it out there, I do agree with Illuminarti that the amount of play is quite substantial.

 

I'm not sure which part you mean is bent... The belt is loose but the other parts seems to be pretty fine.

Can you explain?

 

[hieronymus 0]

The endstop I mentioned is the little black block that's glued to the side of the case (in your pictures it's behind the metal bar).

This is a limit-switch and there is another one in the same corner glued tot the roof of the printer; normally as the carriage is moving in a certain direction the printer needs to know when the edge of the buildplate has been reached so it can stop. This is when the limit-switch is pressed and at that point the motor should stop turning.

The metal arm (/clicker) is supposed to be straight, however in your pictures the top part is bent, (If you check, the other limit-switch on your printer is probably still straight), that's why I have a feeling the carriage ran into the switch but didn't manage to stop the motor.

In theory, the motor still excerting force on the belt as one side of that belt is fixed in place, could slightly stretch the belt which would increase it's lenght.

A non-functioning endstop could have several reasons (faulty switch itself, problem/ loose connection in the wiring) but I'm not really all that up to speed with the UM2's wiring-diagram so I can't really help there.

A well functioning (and straight) endstop should make a distinct 'click' when you press it (check with the one glued to the roof) so you could try bending back the metal arm until it is straight and then press it to hear the clicking sound. If it doesn't click it's probably a faulty limit-switch and you would need a new one, if it does click (but was unale to stop the motor) it's probably the wiring, but perhaps Illuminarti can help with that.

Hope all of that made sense