Hatch Distance and Scan Distance

Question

I am going through some of the basics about one of the 3D printing techniques - Selective Laser Sintering, and I am confused between the above mentioned parameters - scan distance and hatch distance. Are they the same ?

How do we calculate the value - the overlapped area of two parallel scan lines in linear scanning technique. There must be some area of overlapping for the selective laser sintering to work.

Any idea ?

Answer 1

Scan spacing

Within each of the ‘islands’, simple alternating scan vectors are used with the spacing between these vectors defined as the ‘scan spacing’ and the speed with which the laser spot moves across the surface defined as the ‘scan speed’.

Source

• The influence of the laser scan strategy on grain structure and cracking behaviour in SLM powder-bed fabricated nickel superalloy
• chapter: 2.2. SLM processing and laser scan strategy

Hatch distance

The stripe pattern is a band defined by the scan vector width (ie stripe width), the hatching space between adjacent tracks and the scan direction as well as the overlap with the neighbouring stripes

Source

• Scanning patterns in SLM

Notes

• The computer controlled laser scans the surface of the bed to selectively melt the current two-dimensional slice of the CAD file.
• The laser scanning remelts some of the previously built layer to ensure good bonding between layers and a fully dense component overall.
• Cool printing image