1 (edited by dutch_fila 2014-02-25 11:15:10)

Topic: Splits in big objects (ABS, Ultimaker 1)

Hi guys,

Every time I print large objects with ABS there appear splits in my prints.
I need the objects as strong as possible. Does anybody know a solution for it?

I add a picture where you can see what kind of splits I mean.

Ultimaker settings I use:
Layer height: 0.2mm
Shell thickness: 0.7mm
Bottom/top thickness: 1mm
Fill density: 20%
Print speed: 70
Printing temperature: 250
Bed temperature: 110
Fan speed: 50

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2

Re: Splits in big objects (ABS, Ultimaker 1)

Have you tried a different spool of filament?

3

Re: Splits in big objects (ABS, Ultimaker 1)

Is the fan blowing all of the time, or is it only on for small layers and bridges?  Keeping it on all of the time is for PLA.  It will weaken an ABS print by cooling the filament too much before it has a chance to bond.

4 (edited by dutch_fila 2014-02-27 09:02:12)

Re: Splits in big objects (ABS, Ultimaker 1)

@Knowack, yes I did. But no result.
@IanJohnsos, I tried it both. Both settings face the same problem. The thing is, if I put the fan off the object is more sensitive for deformation. If I put the fan on the structure of the surface looks better but what you say, the layers are less combined. So for the best strength it might be better to turn off the fan.

5

Re: Splits in big objects (ABS, Ultimaker 1)

250 degree's? Woah. Try backing that down to 215-ish.
Is it stupidly cold where your are?

This is a crowd funding thing that I'm running: http://www.gofundme.com/bvi140 It's for pretty selfish reasons tongue

6 (edited by adrian 2014-02-27 10:55:09)

Re: Splits in big objects (ABS, Ultimaker 1)

Serin wrote:

250 degree's? Woah. Try backing that down to 215-ish.
Is it stupidly cold where your are?

OP has an Ultimaker 1 (note subject of thread) - so the temps are measured at the heater block. Solidoodle temps are 25-30°C cooler than other printers because they are measured at the nozzle, hence why SD's use 195-210-ish.. 215 mebbe... - so that temp is actually about fine. 245 maybe... but ultimakers are quite quick, so 250 is probably good to.

Anyway - might just need a full enclosure due to humidity/ambient where he is...

7

Re: Splits in big objects (ABS, Ultimaker 1)

Snap, I'm an idiot.

This is a crowd funding thing that I'm running: http://www.gofundme.com/bvi140 It's for pretty selfish reasons tongue

8 (edited by adrian 2014-02-27 10:55:57)

Re: Splits in big objects (ABS, Ultimaker 1)

Serin wrote:

Snap, I'm an idiot.

Nah, you're just used to a Solidoodle and people with solidoodles asking for help smile you're advice in that instance would be fine smile

9 (edited by dutch_fila 2014-02-27 13:35:32)

Re: Splits in big objects (ABS, Ultimaker 1)

@Serin thanks for your reply, no not stupidly cold.(Amsterdam, The Netherlands)  +10 degrees, but rainy hole day..  enough weather info? wink
@Adrian, I think the temperature is quite ok. If I put the temp. lower than 240 my nozzle gets stuck. So lower is no option.
I want to make sure that my layers combine correctly. The max. print temp for my UM1 255ºC. Could it be helpful to print at with a higher temp than 255ºC, what do you think?

10

Re: Splits in big objects (ABS, Ultimaker 1)

Hmm, I suppose my only suggestion would be to increase the ambient temperature around the printer.
That said, it could very well be something I'm completely unfamiliar with tongue Layer adhesion etc etc

This is a crowd funding thing that I'm running: http://www.gofundme.com/bvi140 It's for pretty selfish reasons tongue

11

Re: Splits in big objects (ABS, Ultimaker 1)

The part will always be weak along the filament joins,

Have you considered printing the part with a recess and separate inserts?

or the core in one direction and a cover?

the simplest way to iillustrate this is with a picture.
I have mounted the power supply on a board that stand vertically.

my brackek goes over the whole power supply and thus must be printed so that layers will intersect a hole. when a screw is used this will force the layers apart since the part is weakest at the lamination.


http://i160.photobucket.com/albums/t166/daniel_rainbow/solidoodle/IMG_5245_zps9c01376d.jpg

the simple solution is to make the hole oversized so that the screw passes through easily and puts no stress on the layer joins.
and then make a cap

http://i160.photobucket.com/albums/t166/daniel_rainbow/solidoodle/IMG_5247_zps65bd4d6c.jpg

the screw goes into said cap, all "lateral" forces outwards (from the countersink head) are constrained by loops of plastic within the layer, "downward" forces only serve to try to squash layers closed together...


try putting a recess (perhaps 2 - 5 mm) in the top and in the back, then print an insert to exactly match the hole, the part would then be stronger.