Prints breaking as they get taller
February 18, 2013 05:32PM
I have been trying to print a new x carriage but the bearing holders keep breaking when I try to remove the finished part. It is this part: [www.thingiverse.com]

Is there something I need to calibrate to keep layers from being brittle? Anything I print that is taller than 2cm becomes brittle.
Re: Prints breaking as they get taller
February 18, 2013 06:18PM
What plastic are you printing with?
What settings?
Can you show a picture of the issue?
Re: Prints breaking as they get taller
February 18, 2013 06:23PM
Delamination is usually caused by poor layer to layer contact For instance, if you're not extruding enough material, it may never contact the lower layer properly to bond the two. Too much active surface cooling could do this as well, I think.

fwiw, in general, it's nice to know the material you're printing with (ABS, PLA, etc.) the hot-end temperature, layer thickness, etc. in order to clarify and isolate common problem sources.
Re: Prints breaking as they get taller
February 19, 2013 05:55AM
Or the Z having an incorrect steps/mm value.
Re: Prints breaking as they get taller
February 19, 2013 06:58AM
increase flow rate slightly like by 2% or less.
Re: Prints breaking as they get taller
February 19, 2013 01:01PM
I find the two main culprits to be:

Wrong layer height. (trying to print .4 layers with a .35 head...)

printing too cold. I've had beautiful prints that would break easily with a little pressure. Bumped the temp up 5deg. and the same print came out Solid!

Also I hear too much cooling (fan) can cause PLA to not bond properly also.


Komb'
Glankonian Protoforms
Re: Prints breaking as they get taller
February 19, 2013 01:08PM
+1 to the too much cooling cause, as well as hotend temp too low. Both of these have the ability to cause poor layer adhesion.

But in the OPs case, as few details as we have, he says they are breaking as they get taller... This leads me to believe he is using an improper steps/mm (too high?) Which is causing the layers to get progressively further apart in height as he prints.
Re: Prints breaking as they get taller
February 19, 2013 07:14PM
Printing with 3mm ABS to 0.5mm. Using Slic3r speed: infill perimeter at 40mm/s
Re: Prints breaking as they get taller
February 20, 2013 01:41AM
You mean you are using a 0.5mm layer height on a 0.5mm nozzle?
Re: Prints breaking as they get taller
February 21, 2013 09:36AM
Ya, IF your nozzle is 0.5mm you should be printing at 0.4mm or lower layer heights. 0.45mm on the outside.

The layers need to be slightly squished into each other to make a good bond.

At 0.5mm on a 0.5mm nozzle they are just laying on each other. very little surface contact to bond with.


Komb'
Glankonian Protoforms
Sorry, only registered users may post in this forum.

Click here to login