Fab@Home Version 0.21 Release Notes

This release includes fixes for the following known bugs:

When pausing during a build, the system would frequently return to the wrong position, resulting in an offset in subsequent part layers which usually ruins the part being built.
This has been tracked down to a synchronization error between the microcontroller and the application, and corrected, and now the autocalibration pausing should reduce position errors during builds, and improve build quality - remember to experiment with PATHSPEED and PAUSEPATHS in your tool files.

The release includes the following new features:

Tool files may now include SUCKBACKDELAY as a parameter.  This pospones the onset of the SUCKBACK phase of depositing materials (reverse motion of the syringe piston to stop flow) for an amount of time (in seconds) ranging from 0 (default) to SUCKBACK.  When suckback is delayed, on boundary paths (around the outside or inside edges of a part) the machine will continue to move around the boundary until the suckback has completed, with the effect of improving the connection between the start and end of the deposited material on the path.  On raster fill paths (back and forth motion which fills in the region inside of boundary paths), the delay causes the machine to halt at the last vertex of the path until suckback is complete. Careful tuning of PUSHOUT, SUCKBACK, SUCKBACKDELAY, and DEPOSITIONRATE should yield improved part quality.

The application now can import "Vector data files" (.vct or .txt suffix) as well as STL files.  Vector data files are simply ASCII files with rows of X Y Z triples of floating point numbers representing vertices along a path.  The end of a path is marked by a blank line.  // can be used to indicate a comment. The paths need not be planar.  Once they are imported (use Model->Import Geometry, and filter for Vector Data Files), they can be treated just as STL files - materials may be assigned, and the vectors may be rotated, translated, or scaled, and can exist in the same model as an STL file. Units are millimeters. For example:


//This is a vector file.
//this draws a square 10.3 mm on a side
0 0 0
0 10.3 0
10.3 10.3 0
10.3 0 0
0 0 0

//the blank line above indicated the end of the first path
//here is a 3D path
0 0 0
0 10 10
5 5 5
0 0 0