[KwartzLab] 3D Printer: Next Steps

[doug moen]

Okay, I've now read enough blog postings, etc, to come to some conclusions.
* When you build your own reprap, it's a DIY research project.
* Part of that research project is hacking together a working software
toolchain, which requires debugging and modifying software.  You can't
expect to just download polished, bug free working software.

We built our reprap from a Tech Zone kit, one which includes a
particular version of the Tech Zone Gen 3 Electronics Remix.  Tech
Zone sold HUNDREDS of these kits (possibly with several versions of
the electronics) before doing a complete redesign and creating a
"monolithic" single board controller.  This is hardly mass production,
so there are relatively few people with hardware like ours, relative
to more commercial 3D printers like the MakerBot and the MakerGear
Mosaic (which come closer to the ideal of 'plug it in and it works').
MakerBot has their own software development team, and have created
polished, working software that works with their hardware.  Nothing
like that seems to exist for Tech Zone hardware.  The software is DIY.

http://adventuresin3-dprinting.blogspot.com/2010/11/what-causes-warts.html
is someone else who has our kind of hardware, and who has also
discovered that SkeinForge does not generate GCODE that is compatible
with his firmware.  In this blog post, he analyzes a particular kind
of printing error ("warts") that we are not far enough along yet to
care about, explains how it is caused by bad GCODE, and how to fix it
(he wrote his own GCODE postprocessor). And, of course, we've
identified our own problems, different from "warts".  Kevin has
figured out that the M108 codes generated by 3dtoolchain.com are
incompatible with the FiveD firmware, and screw up our prints. And
there is the still undiagnosed problem of the Y axis jumps (when
printing SkeinForge generated GCODE), which is probably also a GCODE
problem.

I don't think there is any GCODE generator that works correctly with
our firmware.  I kind of doubt that a working firmware/GCODE generator
pair exists for our hardware as packaged software that you can just
download and run.  Maybe there is firmware that is better than FiveD
and works with our hardware, if so I'd like to know about it.  I'm
more certain that there is no working GCODE generator, and that
hacking Skeinforge is the best way forward.  [I've cc'ed Kimberly from
Tech Zone. She can correct me if I'm wrong.  But since Tech Zone's own
3dtoolchain.com software generates GCODE that is incompatible with our
firmware and hardware, I'm not optimistic.]

I'm a software engineer.  I don't have Kevin's hardware smarts.  My
plan is to hack Skeinforge (and possibly the FiveD firmware) until we
can generate GCODE that is compatible with our firmware.  Some of the
hacking will just be Skeinforge configuration settings (the goal is to
come up with a machine configuration file that works with our
printer).  Some of the hacking will involve adding new configuration
settings to Skeinforge so that we can accurately describe our hardware
and firmware.  I'll contribute the changes back to Skeinforge.
Ideally, I shouldn't modify the firmware unless necessary, I should
try to make Skeinforge work with our firmware, not vice versa -- that
way, my changes will be useful to a larger group of people.

There are other ways forward.  We could replace our electronics with
something more modern, eg a single board solution that is compatible
with the hottest and most capable firmware and software (eg, Sprinter
firmware and the Pronterface front end).  That will require time and
money, and I suspect we will still need to hack software.

We could also get a new 3D printer, something that is closer to plug
and play than a reprap.  That requires another $1000 in funding, more
or less.

The end goal is for our space to provide a 3D printer that can be used
by artists and other makers, people who are not interested in reprap
hacking.

Doug Moen.