Skeinforge 40 and Gen6 electronics (with Wade extruder)
Graham Klyne
I thought I'd already posted something about this, but it appears not.
I've had my Mendel sort-of working with Mendel-parts Gen6 electronics and
RepSnapper. But the RepSnapper G-code generation is very poor so I've been
trying to use Skeinforge (040) to generate the G-code.
I learned that the 5-D firmware, which is the basis for the Gen6 firmware, is
so-called because rather than controlling extruder rates through separate
comments, it adds a 5th "dimension" to each GCode command for extrude length.
My problem is that Skeinforge 040 generates extrude length values that are *way*
too small for my default setup. Repeated hunting through Skeinforge settings
has failed to locate any parameter to control the extrude rate.
(The main Skeinforge tab covering this is "Dimension", which is not exactly
evocative.)
I finally figured out why (though have yet to test this): the extrude rate
(steps per mm) is set in the firmware, not in Skeinforge. And with Skeinforge
040, the expected value for extrude rate is steps per mm of *feedstock*, not
extruded output. So the "official" approach is to modify and reload the
firmware with newly calibrated values (BTW, can also be used to fix stepper
motor directions). I have been trying to avoid re-loading firmware until I had
a basic working platform.
Anyway, it turns out there's some fairly extensive discussion of this issue here:
http://forums.reprap.org/read.php?154,75635
which includes some thoughts for fudging the parameters to get something working
without re-flashing the firmware.
In theory, when the formware is calibrated to the local machine (where the
diameter of the hobbed extruder drive bolt is a per-machine variable), the rest
of the parameters can be calculated based on the required print characteristics.
...
When we get some machines built and working, I tink we could really use some
print parties to spread knowledge about how to use the various software
toolchains, and maybe fix some bugs in the host software on Linux. (I've given
up on Linux for host s/w for the time being, and am using Win7 on a NetBook, but
do have hopes to eventually revert to a proper operating system.)
#g
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