UM2 overhang curling -> new fan shroud?

[rhino_aus 2]

I am having some issues with my new Ultimaker 2 printing overhangs. when I print an overhung object the corners curl upwards and ruin the print. I have tuned the temperatures to the point where it only seems to occur in the back right hand corner of the print. My current settings are 100mm/s, 210 C and 100% fan always. I believe is that this issue is due to the reduction in cooling in that corner due to the design of the fan shroud, as the nozzle is offset from the fan center.

Does anyone have either:

1) Suggestion on how to fix this problem

2) a link to a file that is a replacement fan shroud for the UM2. I have found plenty for the UM1, but not for the UM2.

A replacement shroud would be nice and the current one is really vibraty and noise unless I bend it a little (which only solves the issue for an hour or two)

 

[Dim3nsioneer 521]

There is a whole thread about the issue of raised edges: http://umforum.ultimaker.com/index.php?/topic/4094-raised-edges/

 

[eldrick 63]

venkel, the designer, has uploaded several fan duct designs to youmagine.

Here you go: https://www.youmagine.com/designs/fanduct-another-idea

These are improvements to the point where a couple of us find that we turn the fans down from the previous setting. An ABS shroud also gets rid of a surprising amount of noisy resonance and fan noise vs. the OEM metal one.

Difficult to find on youmagine, as youmagine tagging and search are remarkably primitive and ineffective. Why they don't use Google search on the site is beyond me...

 

[gr5 1,451]

The link that dimensioneer provides talks about this issue. Read post #41.

It helps to give each layer lots of time to cool - so 100mm/sec is too fast if each layer is printed in only 15 seconds. Normally 5 seconds is plenty of time to cool but for these annoying overhang/curling issues I'm not sure what's long enough. Maybe 20 seconds is enough.

And fan fan fan. Take out a window fan put it on the top. Put another window fan on the side, put a hand fan inside the machine. I don't know what to do but definitely more fan helps! You want the plastic to cool INSTANTLY before the head moves a whole 2mm away.

 

[rhino_aus 2]

And fan fan fan. Take out a window fan put it on the top. Put another window fan on the side, put a hand fan inside the machine. I don't know what to do but definitely more fan helps! You want the plastic to cool INSTANTLY before the head moves a whole 2mm away.

 

I thought this is the case as the corner near the fan prints perfectly 100% of the time and the one furthest from the fans curls 100% of the time. Will print a new shroud in a few days when I get back home and see how it improves.

 

[bob-hepple 59]

I found the design for the cooling duct and printed it pla as it was loaded on the machine do you think I waisted my time heat wise

[eldrick 63]

Use ABS, not PLA.

 

[IRobertI 468]

Difficult to find on youmagine, as youmagine tagging and search are remarkably primitive and ineffective. Why they don't use Google search on the site is beyond me...

 

They are working on improving the search functionality. Also, nothing is stopping you from using google to search the site instead, just add "site:youmagine.com" to the end of your search terms.

 

[Tinkerpete 0]

Wrong post!