View source for User:Mct/shopbot auth 1 notes

* 3-axis routing with 2.5d designs
** can't cut overhangs
** continuous xy movements with discrete z steps
** shopbot's axes:
*** x: long side of the table - to the right, when sitting at the control computer
*** y: short wide of the table - forward, when sitting at the control computer
*** z: vertical
* shopbot can handle continuous z, but the toolchain taught here won't go over how to do that


* workflow: design (CAD) -> layout, tooling, speed (CAM) -> machine (CNC code)  
** CAD just concerned with the shape to be machined
** CAM concerned with the interface between the design, the materials, and the machine
* vcarve: handles CAD & CAM (& can import CAD stuff from other programs)


* CNC code, 'toolpath':
** gcode
** openbsp (used on shopbot routers)


* main toolpaths - all have depth parameters:
** profile
*** remove material along a shape
** pocket
*** remove material over an area
** drill
*** just plunge at a point


* securing material (sheet wood) to table: plastic nails
** still should be careful about nail placement


* end mill (router bit) properties
** cutting diameter
*** small tools generally take longer than big ones, but can do finer cuts
** shank diameter
** nose shape
*** square
*** v
*** ball
** flute count
** flute shape
*** up/down
*** spiral
*** straight
*** roughing


* CAM cut variables - affect time and quality of resultant cut:
** cut depth - depth of the final cut
** pass depth - depth of each pass
*** should not be greater than cutting diameter
** stepover - horizontal thickness of each pass
*** only relevant for pocket cuts
*** 40% of cutting diameter (rule of thumb)


* rate variables:
** spindle speed - RPM of tool
*** 12k to 16k generally, max 18k
** feed rate - tool speed in plane (x-y)
*** deterimined using chip load calculator
**** feed rate = chip load * flute count * spindle speed
***** chip load (in)- material removed per flute cut
****** function of material & cutting diameter
***** flute count (flutes/rotation)
***** spindle speed (rotations/min)
***** feed rate (in/min)
**** can also generally be looked up in a chart
*** under 200 in/min, but not too slow
**** machine can be kept within appropriate operating parameters by changing input variables (i.e. varying tool, spindle speed)
*** max on shopbot: ~360 in/min
** plunge rate - tool speed in z
*** 50% of feed rate (rule of thumb)


* vcarve
** workflow
*** enter material parameters
*** create or import design
*** enter toolpaths mode, assign toolpaths to portions of the design
** material dimensions
*** 'job size' establishes material shape in plane
*** 'material' establishes material thickness
**** nominal thickness should not be trusted - rather, should be measured with calipers by shopbot station
*** 'xy datum' positions origin
** design modes
*** drawing modes have to be explicitly exited to switch 
*** transform - click to select, then click again to enter mode
** toolpaths
*** select shape(s), then set toolpaths
*** profile
**** add 0.05''  to depth
*** tool parameters
**** use tool number to order multiple tools in a single job
***** have to change them manually