Monday, April 12, 2010

Bookkeeping and janitorial duties

There isn't much that is flashy to report at this time. A lot of my time in the past few days has been focussed on a telepresence 'bot project I have intended to design and build for years that the Rapman finally lets me design and print parts for. Oddly, though, getting the basic software modules that will control the 'bot all working together looks to be far harder than printing and building the 'bot itself. I guess that having worked on Reprap for five years now makes me a lot less intimidated by hardware tasks than previously.

Last week, I discovered that Slice and Dice's vectorization routine, which converts pixel defined boundaries to print areas into vectors usable in gcode, wasn't particularly nice. It was not reducing the boundary definitions nearly as much as it ought to have been. What that means as a practical matter is that it generates a lot more gcode than it ought describing very sort little print roads of a few tenths of a mm. Rapman is not designed to deal very efficiently with that kind of gcode and what happens is that the print speed drops well below the nominal rate set with the "F" specification. That not only wastes time but also puts more plastic on the print than it needs to have in areas where the perimeter curves. THAT makes for poor print quality.

I got to the bottom of that problem over the weekend.

As I set up for testing some new approaches to vectorization, I remembered that shifting from BMP to PNG reduced the disk requirements for a print project dramatically. I have plenty of disk space, but the reduction in disk requirements led me to redesign the files handling for Slice and Dice so that one can readily process and work with more than one print project at a time. That job holds no challenges as such, but is merely a bit of tedious restructuring files handling routines and testing to make sure that they all work. I've got that about two-thirds done.

Thus, slowly but surely Slice and Dice begins to look like very preliminary beta code.