First Layer Adhesion - Stratasys FORTUS 360mc Service Manual

• Extrusion speed can vary, but must strike a balance between 'too slow'

First Layer Adhesion

Purpose
The platen and build sheet are not perfectly level - therefore a slight variation exists in the
gap between the Model tip and the top surface of the build sheet as the tip travels across the
platen.
Oven temperature, due to thermal expansion within the build envelope, is also a key
consideration when modeling the first layer.
The first layers of a part lay the "foundation" on which the part will build.
The unique requirements of the first layers demand special parameters be applied to them.
Operation
1.
Insight creates a 'base' when the part is processed for modeling.
• The base consists of four layers of model material, followed by either 1 or
• The support layer is 'solid' fill.
• The completed base establishes a stable, level surface for building a
2.
The part build begins with the Model tip moving into position to start the first toolpath of
the layer with the Z stage at the Z Zero position.
• The gap between the Model tip and the build sheet is greater than that of
• The extra gap compensates for slight out-of-level platen conditions - as
• The extra gap also compensates for minor build sheet surface
3.
For the first layer, the extrusion rate is greater (approximately 3 times) than normal and
the head moves at a slower speed than normal
• The extra volume of material fills the extra gap and levels the path.
• The slower speed allows for better material adhesion to the build sheet.
It is also important that the build sheet be heated to the correct build temperature to improve
adhesion of the first layer.
Z Zero position is another critical factor. Thermal expansion or contraction that occurs after
the last Z Zero calibration affects first layer extrusion results. (See
FORTUS 360mc/400mc Service Manual
and 'too fast'.
2 layers of support material (depending on parameters from Insight).
model.
'normal' layer thickness.
long as the platen is level to within specifications.
imperfections.
"Thermal Expansion" on
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