On 11/02/2016 11:05, T i m wrote:
On Thu, 11 Feb 2016 09:30:08 +0000, dennis@home
wrote:

snip

With FFF in plastic you may have to look at the design and change it to
take into account the weakness in the Z axis. If you can't then you need
to look elsewhere.

What weakness in the Z axis?

You can never get as good a bond when laying hot plastic ontop of cold
plastic as you get from the extrusion.
Try printing a tall rod vs one printed on its side.
You will find one has a higher tensile strength than the other in the
long axis.


If the printer is configured and running properly then each new layer
should fully fuse itself to the previous layer? We extrude PLA at
around 200 DegC and using a heated bed (60 DegC).

Don't get me wrong, I have had faulty prints where the nozzle has say
partially blocked for a few seconds, the size / consistency of the
extrusion has been compromised and so a fault is created affecting the
Z axis but that's a 'manufacturing' not 'materials' fault.

I'll print a couple of solid beams and see how accurately I can test
them for bending / delaminating failure.

O, that's what i just suggested above.