Print head clipping print UM2

[jet3d 0]

Hi guys,

When printing, after a while, the print nozzle sounds like it is clipping the print. Often, I return to find a support snapped off. The result can be seen in the gallery area.

The prints look fine apart from issues with support failure.

It seems to get worse the higher the print.

I know this sounds like an obvious fault due to base plate not being calibrated or an out of date firmware, but I am running the latest CURA and firmware. The plate is level. Temps are at default. Belts are tight.

Any ideas?

Kind regards, Jet

 

[SandervG 1,519]

I think that it happens because of a support structure being rather sparse, so it is easier to break off.

The fact that it is sparse, and tall, and has a relatively small footprint, makes it easy for the printhead to put it out

of balance while putting up the next layer on top. Once it is out of balance it can be knocked over the next time the print head crosses over.

What you could try is a bit stronger support structure, or a brim. (not sure about the brim though, if that will help the support structure.)

 

[gr5 2,072]

Not sure. Would be best if you could photograph the shape of the supports before they break off. Or post a picture of what it looks like. You designed the supports yourself? I'm really surprised they would break off in the middle, and not at the bottom. I guess you just need thicker supports maybe? And try to make them mostly vertical.

There is a problem with supports or objects that "lean outward". When the PLA shrinks it pulls to the middle and tends to rotate the upper (current) edges of these parts to the vertical which causes them to be tall enough to get hit by the fan shroud.

So try to stick with vertical supports and don't let the supports get wider as they get higher - make sure they either stay the same width, or get narrower.

 

[jet3d 0]

Thanks mate!

I use BRIM - but, the support was a little light.

Should the nozzle tip sound like it is clipping the print? Is this normal?

Regards, Jet

 

[gr5 2,072]

And here is the image jet loaded. Jet next time after loading to gallery, when you make your post, click "my media" next to the smiley face.

 

 

[jet3d 0]

Hi Ultimaker User....

The pic of the print is in the Gallery section - this has occurred a few times now...

 

[SandervG 1,519]

How do you mean clipping?

And what GR5 is also true. When you are slightly overextruding or when the edges curl up a little bit this can also create a ticking (clipping?) sound, and in worst case tip your support over.

 

[gr5 2,072]

Should the nozzle tip sound like it is clipping the print? Is this normal?

 

It's not good but it happens all the time. It tends to happen like I said when the edges are lifting. It has to do with PLA shrinking - it has nothing to do with the accuracy of the UM. Upper layers of PLA pull in and the lower levels get compressed horizontally and if the part is shaped like an upside down pyramid, the walls rotate upward and get hit by the nozzle.

In theory the solution is to have a heated chamber above the glass temp of PLA (around 65C) but in practice I can fix this with the right shaped support.

 

[jet3d 0]

OK lol..... still getting used to the forum - sorry and thanks for your advice!

Jet

 

[gr5 2,072]

when the edges curl up a little

 

Yes - that's what I have experienced. I assume this is the same thing. I suppose it could be a blob on the currently-top-layer also.

Clipping has many meanings but one is a sports term where player 1 collides with player 2 but player 1 keeps moving and is mostly unaffected. Player 2 however is usually affected and unhappy. Happens in basketball, hockey, football (american) and football/soccer.

 

[mostlyatomicbob 34]

Jet,

I sent you an email, with a couple of pics which should help with your settings.

Bob

 

[jet3d 0]

Guru.... ; )