PLA curling up on the corners

[Wil Chung]

Hi all,

I've gotten the hang of ABS's temperament, and managed to find good ways to fight ABS curling (enclosure, and painting a thin layer of ABS/acetone slurry on the platform).  I started printing PLA on the makerbot replicator, and I found that while it stuck to glass great and popped off after cooling, it's temperamental in its own way.

When I'm printing objects with sharp corners or a slight sloping overhang, the corners of the print tend to curl up. Whereas in ABS, the bottom of the print curled, in PLA, the top of the print curls. It seems like when when nozzle traces the corner, it "pulls" the corner, and each successive layer just pulls it inward more and more, til it looks like the object is growing 'horns'. This happens until the nozzle knocks into the horn, and messed up the print.

On the rep rap machines, I see that there's an extra fan cooling each layer as it's printed. On the replicator there's no such thing. Are the settings to combat this effect? (I'm guessing Cool in skeinforge?) Or is there something on thingiverse that can be an addon to cool each later?

Thanks

Wil

[CarryTheWhat]

Bump... I'm printing PLA for the first time, and having the same problem. Particularly at steeper angles, the curling is a lot worse than ABS.

I'm printing at 1 or 2 shells, 10-20% infill -- at 205C.

What are the proper settings?

[JohnA.]

The Replicator2 has a printed duct on it to cool the PLA as it prints, as do just about all the other printers that are primarily used for PLA.

 

Somebody has to have designed one by now for the Replicator?  We had 'em for the cupcake / ToM....

 

 

JohnA.

 

On Friday, September 14, 2012 8:05:25 PM UTC-4, Wil Chung wrote:

[Andrew Plumb]

This MK7 variant may be adaptable:

http://www.thingiverse.com/thing:16392

Andrew.

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[Wil Chung]

So there's nothing specifically for MK8. I'll try adapting the MK7. Thanks for the link. I figured with all the replicators out there, there'd be some tips from people already printing PLA. Or else my temperature is set too high at 190C. What does everyone print PLA temp at?

Wil

Wil Chung
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