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3D Metal Printing Slicer Plugin

This is a plugin for the slicing software Cura which will create G-Code specific for the MOST delta Open-source metal 3-D printer.
NOTICE: This plugin is only tested to work with Cura v14.x. It is not guaranteed to work on any version of Cura greater than 14.x.

Installation Instructions

• Download the Welder.py file from here.
  • If you cannot obtain the code from GitHub, copy the code from below and save it as Welder.py

#!/usr/bin/python
#Name: Welder
#Info: Mangle GCode to work on welder (2014-02-10)
#Depend: GCode
#Type: postprocess
#Param: speed(float:10) target extruder speed (mm/s)
#Param: mindist(float:1) minimum travel distance to switch off welder (mm)
#Param: ON(str:G4 P0;M42 P0 S3) Commands to insert after travel
#Param: OFF(str:G4 P0;M42 P0 S0) Commands to insert before travel

import sys

__author__ = 'Bas Wijnen <wijnen@debian.org>'
__date__ = '2014-02-10'
__license__ = 'GNU Affero General Public License http://www.gnu.org/licenses/agpl.html'

try:
	infilename = filename
	outfilename = filename
	ON = ON.strip ().replace (';', '\n') + '\n'
	OFF = OFF.strip ().replace (';', '\n') + '\n'
except NameError:
	#assert len (sys.argv) in (3, 5)
	infilename = sys.stdin
	outfilename = sys.stdout
	speed = float (sys.argv[1]) if len (sys.argv) > 3 else .8
	mindist = float (sys.argv[2]) if len (sys.argv) > 4 else 1.
	ON = 'G4 P0\nM42 P0 S3\n'
	OFF = 'G4 P0\nM42 P0 S0\n'
extruding = False
pos = [0., 0., 0., 0.]
erel = None
rel = False
edata = [0.,0.]

def parse (line):
	edata[0] = pos[3]
	global rel, erel, extruding
	if ';' in line:
		l = line[:line.find (';')]
	elif '//' in line:
		l = line[:line.find ('//')]
	else:
		l = line
	components = l.split ()
	if len (components) == 0:
		return line
	if components[0] in ('M109', 'M104', 'M190', 'M140'):
		return 
	if components[0] == 'G90':
		rel = False
	if components[0] == 'G91':
		rel = True
	if components[0] == 'M82':
		erel = False
	if components[0] == 'M83':
		erel = True
	if components[0] == 'G92':
		for w in components:
			if w[0] in 'XYZ':
				wh = ord (w[0]) - ord ('X')
				pos[wh] = float (w[1:])
			elif w[0] == 'E':
				pos[3] = float (w[1:])
	if components[0] not in ('G0', 'G1'):
		return line
	parts = {}
	for p in components[1:]:
		if p[0] in parts or p[0] not in 'XYZEF':
			print 'warning: %s' % line
			return line
		parts[p[0]] = float (p[1:])
	x = []
	for i, c in enumerate ('XYZE'):
		if c in parts:
			x.append (parts[c] if (rel if i < 3 or erel is None else erel) else parts[c] - pos[i])
			pos[i] += x[-1]
		else:
			x.append (0.)
	dist = sum ([t ** 2 for t in x[:3]]) ** .5
	if 'E' not in parts or x[3] <= 0:
		if extruding and dist > mindist:
			extruding = False
			return OFF + line
		return line
	del parts['E']
	t = x[3] / speed
	parts['F'] = dist / t * 60.
	ret = 'G1 ' + ' '.join (['%s%f' % (c, parts[c]) for c in parts])
	if not extruding:
		extruding = True
		return ON + ret
	edata[1] = pos[3]
	return ret


try:
	if isinstance (infilename, str):
		with open (infilename, "r") as f:
			lines = f.readlines ()
	else:
		lines = infilename.readlines ()

	if isinstance (outfilename, str):
		with open (outfilename, "w") as f:
			for line in lines:
				f.write (parse (line.strip ()) + '\n')
	else:
		for line in lines:
			outfilename.write (parse (line.strip ()) + '\n')
except:
	print ('something was wrong:', sys.exc_value)

• Open Cura and make sure the switch to full settings is selected under the expert menu
• Click on the plugin tab and navigate to the bottom of the screen where there is an "Open plugin location" button
• Click on the button and it will open up a file browser window, drag and drop the Welder.py into the window, and close the window.
• Restart Cura and the Welder plugin will be in the plugins box.

Use

• To use the Welder plugin double click on it and a Welder window will appear in the "Enabled Plugins" section of the tab.
• There are a few different options the plugin as seen in Figure 1.
  • The target extruder speed is the target speed for the bed to move while the welder is turned on.
  • The minimum travel distance to switch off welder is the minimum distance the welder has to travel before the plugin will insert a command to turn it off.
    • Set this value at around ten unless you have a very special print. It is not good to constantly switch the welder on and off because doing so will eventually overheat the welder
  • The commands to insert after/before travel inserts the entered G-code after and before a large block of movement set by the field above.
    • For example G4 P5000;M42 P1 S0 for the MOST delta Open-source metal 3-D printer will pause the welder for 5s and then turn the welder on.
• Once you have entered your values in the plugin, slicing is the same as normally using Cura.
• After you have sliced the G-code, go back and double check the code for any conflicts.

See also

• Open-source metal 3-D printer
• MOST open-source metal 3-D printer v2
• Low-cost Open-Source Voltage and Current Monitor for Gas Metal Arc Weld 3-D Printing
• Integrated Voltage—Current Monitoring and Control of Gas Metal Arc Weld Magnetic Ball-Jointed Open Source 3-D Printer
• Substrate Release Mechanisms for Gas Metal Arc Weld 3D Aluminum Metal Printing - how to get your print off the substrate with a hammer
• In Situ Formation of Substrate Release Mechanisms for Gas Metal Arc Weld Metal 3-D Printing
• Aluminum substrate cleaning for 3-D printing:MOST