skeinforge plugin for makerbot firmware driven stepper extruders

[Len Trigg]

Rick, Tony, and other budding stepper extruder users,

With makerbot firmware patched for a stepper extruder the gcode needs
to be altered so that speed variation is accomplished using RPM
setting M108 Rnnn commands instead of the usual PWM controlling M108
Snnn commands.

It is pretty easy to postprocess cgode to make these changes (I did it
with sed initially) but it's one more thing that you need to remember
to do. I've written an initial wee skeinforge plugin to do this
operation - the advantage is that then it can happen automagically
when you skeinforge, and you can turn the plugin on and off as part of
your usual skeinforge profiles. It can also optionally insert an
initial M108 Snnn command to set the desired PWM if you're using the
extruder controller rather than a stepper driver board. I am using
skeinforge 2010-02-25 (the one that came bundled with skeinfox),
hopefully it can be dropped into other versions easily.

Note: I'm only just getting my stepper extruder working, and got to
the point of doing a couple of test cubes (using the sed script)
before my PTFE barrier failed (it was recycled from my makerbot and so
the threads were dodgy) - thus the output of this plugin has not
actually been tested on a real printer. It looks OK to me, but please
let me know if it works (or not).

Cheers,
Len.

[Len Trigg]

If anyone is interested, I have attached a version of this plugin that
works with skeinforge-27. No other changes. I have been using this
with my stepper extruder and it works fine.

Cheers,
Len.

[Koen Kooi]

Does sf 27 have an option to slow down on corners with a stepper extruder?

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> <rpmify.py>

[Len Trigg]

There is an option to do perimeters at a different speed, but I have
not tried it yet. I don't know about corners specifically.

Cheers,
Len.

[Koen Kooi]

Having a slower perimeter would be good enough for now :) I noticed that when using speeds over ~36mm/s the corners get messy, but that doesn't matter for infill.

[Joshua Updyke]

I am pretty new to this so I am sorry if this is a easy question. How
does one add the rpmify.py plugin to Skeinforge?

Frame - Mendel
Extruder Design - Wade Stepper Extruder
Software - RepG 18

[Len Trigg]

I have not tried the plugin with the older versions of skeinforge that
replicatorg ships with (I use external skeinforge versions), but will
have a look tonight to check whether it is compatible. (when I updated
it to work with the latest skeinforge I basically just had to change
the import statements to reflect the new names). Installation
instructions are at the top of the script, but the essence is to drop
the file into the craft_plugins directory and then edit the place in
extrusion.py that lists the plugin sequence to add rpmify just before
the export plugin.

Cheers,
Len.

[dremd]

Any update on this?
I'd love to get this plugin working with the skeinforge built in to
replicatorg

[Len Trigg]

I had a little look a couple of weeks ago and it looked trickier than
the simple import renaming needed when I updated it to work with the
latest skeinforge, so I didn't go any further (and since I don't use
the built-in skeinforge, there isn't the same itch to scratch).

However, it sounds like this plugin isn't needed if using the
brand-new stepper extruder support that Adam implemented in the latest
experimental firmware (see the updates on the wiki page), so that
could be another option. (I haven't tried out that firmware yet, maybe
this weekend).

Cheers,
Len.