path: root/processes.yaml

author: 'ben lipkowitz'
license: 'GPL2+'
urls: 
- 'http://heybryan.org/mediawiki/index.php/Skdb'
- 'http://fennetic.net/git/gitweb.cgi?p=skdb.git;a=blob_plain;f=materials.yaml'
- 'git://fennetic.net/git/skdb.git/'
source: manufacturing processes reference guide, 1993 first edition. todd, allen, and alting.

template: !process
    name:
    classification:
    mechanism:
    geometry:
        tolerance:
    surface finish:
    consumables:
    functionality:
    parameters:
    safety:
       

abrasive jet: !process #eventually this will be something like skdb.Shaping.Reducing.Mechanical
    name: abrasive jet machining
    mechanism: compressed air accelerates abrasive particles toward the workpiece
    functionality:
    -   finishing
    -   hole drilling
    -   deburring
    -   prismatic geometry
    -   tapered geometry
    machinability: !which workpiece material, machinability
    removal rate: 
        typical: 0.003.. 0.0007in/min #what exactly does this refer to?
        feasible: 0.0001 .. 0.002in/min  
    geometry: 
        primitive: cone #!geometry #what angle?
        path:
        -   parallel to workpiece face
        tolerance:
            typical: +-0.005in
            feasible: +-0.001in
    surface finish: #arithmetic average
        typical:  6..48 microinch
        feasible: 4..64 microinch
    consumables:
        nozzle: &orifice
            tungsten carbide:
                life: 12..30hr
            sapphire:
                #this should work, but it doesn't?
               # life: !range
               #     min: 300hr
        abrasive: 1..25g/min
        #this really should be something like "compressed air: 4.5..7cfm"
        power: 0.5..4 hp #power = cfm * pressure is dependent on pressure and diameter
    parameters: #"factors affecting process results"
        pressure: 25..130psi
        orifice diameter: 0.005..0.05in
        nozzle distance: 0.03..0.6 in
        nozzle angle: 
        workpiece size:
            typical: 5..50 in^2
            feasible: 0.2 .. 100 in^2 #workpiece size is only limited by enclosure
        workpiece material: &machinability
            #on a scale of 0 to 4 representing process quality and/or ease of use
            #need to figure out a new unit 'stars' representing this
            ceramic:
                machinability: 2.25 .. 3.75 stars
            germanium: 
                machinability: 2.2 .. 3.5 stars
            glass: 
                machinability: 2.2 .. 3.8 stars
            mica: 
                machinability: 1.9 .. 3.4 stars
            silicon:
                machinability: 2.3 .. 3.8 stars
            steel: 
                machinability: 1.1 .. 2.5 stars
            aluminum: 
                machinability: 0.4 .. 1.6 stars
        abrasive material:
            aluminum oxide:
                functionality: 
                -   cutting
                -   hard materials
                diameter: 10 .. 50 microns
            silicon carbide:
                functionality:
                -   fast cutting
                -   hard materials
                -   ceramics
                diameter: 25 .. 50 microns
            glass beads:
                functionality:
                -   deburring
                -   light cleaning #how do i parameterize this with dimensional units?
                -   polishing
                diameter: 0.025 .. 0.05in
            sodium bicarbonate:
                functionality:
                -   cleaning
            calcium compounds:
                functionality:
                -   light cleaning
                -   light etching
            magnesium compounds:
                functionality:
                -   light cleaning
                -   light etching
    safety:
    -   airborne dust
    -   flying particles
    -   abrasion
    -   toxic dust
        
arbor milling: !process
    name: arbor milling #really this is just endmilling supported at both ends and you can stack cutters
    classification: process, shaping, mass-reducing, mechanical, reducing, multi-point, milling
    mechanism: rotating toothed cutter supported axially at both ends is fed into the workpiece at a controlled rate
    geometry: #!geometry 
        primitive: revolute #like a candlestick. used to calculate swept volume of tool path
        path:
        -   path perpendicular to axis
        -   axis parallel to workpiece opposite face
        #cutters can be ganged.. where do i put this?
        length:
            typical: 0.2..5in
            feasible: &width_of_cut 0.03..20in
        radius:
            typical: 1.5 .. 10in
        tolerance:
            typical: +-0.005
            feasible: +-0.001
    surface finish:
        typical: 64..200 microinch
        feasible: 32..500 microinch

    unit power: !which workpiece material, unit power
    consumables:
        power: !formula unit power * removal rate
        tool:
            life: !which tool material, life
        lubricant: !which lubrication, lubricant #how long does each lubricant last? where do i get this info?
    functionality: 
    -   roughing
    -   prismatic geometry
    -   !which tool material, functionality #hmm
    machinability: !which workpiece material, machinability
    effects:
    -   surface stress
    -   untempered martensitic layer 0.001in in heat treated alloy steels #blargh
    parameters:
        depth of cut:
            typical: 0.05 .. 0.25in
            feasible: 0.004 .. 1in
        width of cut: *width_of_cut
        rotation direction vs feed: #surely there's a name for this
        #clockwise rotating cutter by default; a counterclockwise cutter reverses this
        -   conventional
        -   climb
        feed per tooth: 0.005 .. 0.010in/tooth
        surface speed: 30 .. 500 feet/min #see materials
        lubrication: !which workpiece material, lubrication
        workpiece hardness:
            typical:
                max: Rockwell C25 #joy~~ how about some real units
        rigidity: #this includes the machine, workpiece, clamps, and tool bit rigidity
            static: #mostly affects deflection or absolute uncompensated accuracy
            dynamic: #affects maximum cutting rate vs surface finish, tool life, etc
        tool geometry: !which workpiece material, tool geometry
        tooth count:
            typical: 10 .. 20 teeth/rev #i just made up these values
            feasible: 1 .. 200 teeth/rev #ditto
        tool sharpness: #units??
        tool material:
            high speed steel:
                functionality:
                -   special geometry
                -   low production
            carbide insert:
                functionality:
                -   high production
            ceramic insert:
                functionality:
                -   high speed machining
                -   high production
                -   uninterrupted cuts
            diamond insert:
                functionality:
                -   high surface finish
                -   low tolerance
                -   nonferrous materials
        workpiece material:
                aluminum:
                    tool geometry: #!multipoint_rotating_cutter
                        teeth: !which tooth count #blarg
                        axial rake: 12 .. 25 deg
                        radial rake: 10 .. 20 deg
                        axial relief: 5 .. 7 deg
                        radial relief: 5 .. 11 deg
                    unit power: 0.3 hp/in^3
                    hardness:
                        typical: 70 .. 125 brinell
                        feasible: 30 .. 150 brinell
                    machinability:
                        typical: 2.6 .. 3.2 stars
                        feasible: 2.2 .. 3.7stars
                    lubricant:
                        -   none
                        -   mineral oil
                        -   fatty oil
                brass:
                    tool geometry:
                        axial rake: 12 .. 25 deg
                        radial rake: 10 .. 20 deg
                        axial relief: 5 .. 7 deg
                        radial relief: 5 .. 11 deg
                    unit power: 0.6 .. 1.0 hp/in^3
                    hardness:
                        typical: 60..100brinell
                        feasible: 50..240 brinell
                    machinability:
                        feasible: 2.1 .. 3.6 stars
                        typical: 2.6 .. 3.1 stars 
                    lubricant:
                        -   mineral oil
                        -   specialty fluid #wtf??
                cast iron:
                    tool geometry:
                        axial rake: 10 .. 12 deg
                        radial rake: 10 .. 20 deg
                        axial relief: 2 .. 4 deg
                        radial relief: 3 .. 7 deg
                    unit power: 0.6 .. 1.1 hp/in^3
                    hardness:
                        typical: 250..320 brinell
                        feasible: 110 .. 320brinell
                    machinability:
                        feasible: 2 .. 3 stars 
                        typical: 2.3 .. 2.6 stars 
                    lubricant:
                        -   soluble oil
                        -   chemical oil
                        -   synthetic oil
                        -   none
                mild steel:
                    tool geometry:
                        axial rake: 10 .. 15 deg
                        radial rake: 10 .. 15 deg
                        axial relief: 3 .. 5 deg
                        radial relief: 4 .. 8 deg
                    unit power: 1.1.. 2.1 hp/in^3
                    hardness:
                        typical: 275..325 brinell
                        feasible: 85..560 brinell
                    machinability:
                        feasible: 2.1 .. 3
                        typical: 2.3 .. 2.6
                    lubricant:
                        -   chemical oil
                        -   syntheic oil
                        -   soluble oil
                stainless steel:
                    tool geometry:
                        axial rake: 10 .. 12 deg
                        radial rake: 5 .. 10 deg
                        axial relief: 3 .. 5 deg
                        radial relief: 4 .. 8 deg
                    unit power: 1.4 .. 1.5hp/in^3
                    hardness:
                        typical: 275..325 brinell
                        feasible: 135..430 brinell
                    machinability:
                        feasible: 0.3 .. 2.4 stars
                        typical: 0.8 .. 1.5 stars
                    lubricant:
                        -   sulfurized mineral oil
                        -   fatty soluble oil
                        -   chemical oil
                        -   synthetic oil
                plastic:
                    tool geometry:
                        axial rake: 18 deg
                        radial rake: 15 deg
                        axial relief: 6 deg
                        radial relief: 8 deg
                    hardness:
                    unit power: 0.05hp/in^3
                    machinability:
                        feasible: 2 .. 3.8 stars
                        typical: 2.5 .. 3.2 stars
                    lubricant:
                        -   mineral oil
                        -   soluble oil
                        -   cold air
                        -   none
    safety:
    -   rotating parts #if this were a high speed rotating part we'd calculate the energy, but the danger is mostly from being crushed by the torque
    -   hot chips #todo: calculate the energy in a typical hot chip
    -   sharp chips
    -   toxic fluids
    
band filing: !process
    #there really wasn't much data on this
    name: band filing
    classification: shaping, mass reducing, mechanical, reducing, multi-point, filing
    mechanism: a prismatic multipoint cutter mounted on a metal belt is fed into the work
    geometry:
        primitive: prism
        path:
        -   under 90 degrees to previous segment #direction of cutting really depends on the tool bit geometry
        -   axis perpendicular to workpiece opposite face
    tolerance:
    surface finish: "fine"
    functionality:
    -   irregular prismatic geometry
    -   deburring
    -   squaring edges
    -   finishing
    consumables:
        tool:
            life:
    parameters:
        tool geometry: #this needs work, should conform to !multipoint_cutter eventually
        -   flat (square)
        -   triangle
        -   half oval
        -   half cylinder
        tooth count: 10..24 teeth/in
    safety:
    -   particulate material
    -   moving belt

band sawing: !process
    name: band sawing
    classification: shaping, mass-reducing, mechanical, reducing, multipoint, sawing
    mechanism: a moving flexible tensioned metal loop with teeth is fed into the workpiece at a controlled rate
    geometry:
        primitive: rectangle
        path: 
        -   roll = 90 deg
        -   perpendicular to rectangle or tangent arc
        -   geometry must extend above and below workpiece
        -   !formula arc radius > something * blade width
        tolerance: 
            typical: 0.05 .. 0.1 in
            feasible: 0.02 .. 0.3 in
    surface finish:
    consumables:
        tool:
        lubricant:
    functionality:
    -   narrow kerf
    -   single angle cuts
    -   !which tooth shape, functionality
    -   !which blade width, functionality
    parameters:
        teeth in contact with work: #!range #FIXME
            min: 2 teeth #bleh
        tooth count: 4..28 teeth/in
        tooth shape:
            precision:
                functionality:
                -   finishing
            buttress:
                functionality:
                -   roughing
                -   parting
                -   high chip load
            claw:
                functionality:
                -   chip clearance
                -   fast cuts
        blade width:
            thin:
                functionality:
                -   irregular prismatic shape
                -   curved cuts
            thick:
                functionality:
                -   straight cuts
                -   parting
        blade thickness:
        blade tension:
        lubricant:
        -   none
        -   soluble oil
        -   cutting oil
    safety:
    -   moving belt
    -   moving blade
    -   particulate material

internal broaching: &internal_broaching !process 
    name: internal broaching
    classification: shaping, mass-reducing, mechanical, reducing, multi-point, broaching
    mechanism: a tapered cutter is fed into a hole in one pass
    geometry:
        primitive: prismatic or helical
        path:
        -   axis parallel to workpiece face
        -   helix angle < 20 deg #yah i made this up.. isnt a tap just a helical broach?
        tolerance:
            typical: +-0.002in
            feasible: +-0.0005
    surface finish:
        typical: 16..63 microinch
        feasible: 8..125 microinch
    consumables:
        tool:
        power: !formula drive efficiency * hardness / chip load #see graph, normalize so that 80% * 100brinnel/(0.01in/tooth) = 0.25 hp/(in^3/min) ... or something like that
    requirements: #do i even need this?
    -   pre-existing hole
    functionality:
    -   heat treated parts
    -   low production
    -   roughing
    -   finishing
    -   internal prismatic geometry
    -   low angle internal helical geometry
    -   keyways
    -   !which tool material, functionality
    machinability: !which workpiece material, machinability
    effects:
    -   welding tool and workpiece
    -   work hardening
    parameters:
        diameter:
            typical: 0.125 .. 6 in
            feasible: 0.04 .. 12 in
        surface speed: !which material, surface speed
        rigidity:
        alignment:
        lubricant: !which workpiece material, lubricant
        feed per tooth: !which workpiece material, feed per tooth
        tool geometry: !which workpiece material, tool geometry
        hardness: !which workpiece material, hardness
        tool material:
            high speed steel:
                functionality:
                -   low production
                -   irregular internal prismatic geometry
                -   irregular internal helical geometry
        workpiece material:
            aluminum:
                feed per tooth: 0.005..0.007in/tooth
                lubricant:
                -   kerosene
                -   mineral oil
                -   sulfurized mineral oil
                tool geometry:
                    rake: 10 .. 15 deg
                    clearance: 1 .. 3 deg
                hardness: 30 .. 150 brinell
                machinability:
                    typical: 2.8 .. 3.2 stars
                    feasible: 2.2 .. 3.7 stars
            brass:
                feed per tooth: 0.004..0.005in/tooth
                lubricant:
                -   water
                -   soluble oil
                -   mineral lard oil
                tool geometry:
                    rake: -5 .. 5 deg
                    clearance: 1 .. 3 deg
                hardness: 40 .. 200 brinell
                machinability:
                    typical: 2.7 .. 3.2 stars
                    feasible: 2.1 .. 3.6 stars
            cast iron:
                feed per tooth: 0.002..0.005in/tooth
                lubricant:
                -   water
                -   soluble oil
                -   sulfurized mineral oil
                tool geometry:
                    rake: 6..15 deg
                    clearance: 2 .. 3 deg
                hardness: 
                    typical: 120 .. 320 brinell
                    feasible: 110 .. 400 brinell
                machinability:
                    feasible: 2 .. 3 stars
                    typical: 2.3 .. 2.5 stars
            mild steel:
                feed per tooth: 0.003..0.004in/tooth
                lubricant:
                -   water
                -   soluble oil
                -   sulfurized mineral oil
                -   mineral lard oil
                tool geometry:
                    rake: 15..20 deg
                    clearance: 1..3 deg
                hardness:
                    typical: 100..275 brinell
                    feasible: 85 .. 375 brinell
                machinability:
                    feasible: 2.1 .. 3 stars
                    typical: 2.3 .. 2.5 stars
            stainless:
                feed per tooth: 0.002..0.003in/tooth
                lubricant:
                -   water
                -   soluble oil
                -   sulfurized mineral oil
                -   mineral lard oil
                tool geometry:
                    clearance: 0.5 .. 3 deg
                    rake: 8 .. 18 deg
                hardness:
                    typical: 135 .. 375 brinell
                    feasible: 135 .. 440 brinell
                machinability:
                    feasible: 0.3 .. 2.4 stars
                    typical: 0.7 .. 1.5 stars
            plastics:
                machinability:
                    feasible: 2 .. 3.7 stars
                    typical: 2.5 .. 3.2 stars
    safety:
    -   reciprocating cutter
    -   hot chips
    -   sharp chips
    -   toxic fluids
    -   flying broken cutter

external broaching: !process
    name: external broaching
    classification: shaping, mass-reducing, mechanical, reducing, multi-point, broaching
    mechanism: a tapered cutter is fed across a workpiece in one pass
    similar: *internal_broaching
    functionality:
    -   heat treated parts
    -   low production
    -   roughing
    -   finishing
    -   prismatic geometry
    -   low angle external helical geometry
    -   gear teeth
    -   irregular prismatic geometry
    -   slot cuts
    -   !which tool material, functionality
    parameters:
        width:
            typical: 0.075 .. 10in
            feasible: 0.02 .. 20in
        tool material:
            high speed steel:
                functionality:
                -   low production
                -   irregular prismatic geometry
            carbide insert:
                functionality:
                -   high production
                -   prismatic geometry
                -   high hardness

superfinishing: !process #somehow i think there isnt quite enough info here
    name: superfinishing
    classification: shaping, mass-reducing, mechanical, reducing, abrasive #is this right?
    mechanism: abrasive surface and oil act as hydrodynamic bearing; surface asperities contact abrasive and are cut
    geometry:
        primitive: cylinder or sphere or cone or plane
        path: 
        -   colinear with workpiece face axis #superfinishing just makes a cylinder "more cylindrical" etc
        tolerance: -0.0002 .. -0.0008in
    effect: removes smeared surface layer
    surface finish:
        typical: 2 .. 8 microinch
        feasible: 0 .. 30 microinch
    rate: 10..40 in^2/min
    consumables:
        abrasive:
    functionality:
    -   high precision
    -   wear resistance
    -   bearing surfaces
    parameters:
        periodicity: #how the heck do i represent this
        surface speed: 50 .. 60 feet/min
        pressure: 10 .. 40 psi
        lubricant:
        -   oil
        -   water
        workpiece surface finish: 30..200 microinch #i made this up.. chrysler recommends rough grinding prior to surface finishing
    safety:
    -   abrasive fluid
    -   rotating parts

gas cutting: !process
    name: gas flame cutting
    classification: shaping, mass-reducing, thermal, torch cutting, gas cutting
    mechanism: ferrous workpiece is heated and then oxidized. gas flow then blows the liquid metal out of the cut
    geometry:
        primitive: cylinder
        path: 
        -   parallel to workpiece face
        diameter: 1/16 .. 1/4 in #kerf
        tolerance:
            typical: +- 1/8 in
            feasible: +- 1/32 in
    surface finish:
        typical: 250..1000 microinches
        feasible: 100..1100 microinches
    consumables:
        fuel consumption: !which fuel, fuel consumption
        oxygen consumption: !which fuel, oxygen consumption
        torch tip:
    functionality:
    -   straight cuts
    -   parting
    -   roughing
    -   irregular prismatic geometry
    -   angular cuts
    -   ferrous materials > 3/8 inch thickness
    effects:
    -   distortion
    -   annealing
    -   microcracks
    -   residual stress
    -   surface embrittlement
    -   oxidation
    heat affected zone: #no mention?
    parameters:
        workpiece thickness:
            typical: 0.125 .. 12in
            feasible: 0.05 .. 60in #wow
        oxidizer pressure: 20 .. 50 psi
        fuel pressure: 3 .. 7 psi
        feed rate: !which fuel, feed rate
        temperature: tempf(1400)..tempf(1600)
        tip style: !which fuel, tip style
        fuel:
            acetylene: #how do i say acetylene is the preferred fuel? least heat dispersion
                tip style: 
                -   one-piece straight tip
                -   one-piece divergent tip
                feed rate: 2.6 .. 20 in/min
                removal rate: 120 in^3/hr
                fuel consumption: 25 ft^3/hr
                oxygen consumption: 155 ft^3/hr
            propane:
                tip style: two-piece recessed tip
                feed rate: 2.5 .. 30 in/min #typo?
                removal rate: 130 in^3/hr
                fuel consumption: 11 ft^3/hr
                oxygen consumption: 167 ft^3/hr
            natural gas:
                tip style: two-piece recessed tip
                feed rate: 3 .. 20 in/min
                removal rate: 130 in^3/hr
                fuel consumption: 20 ft^3/hr
                oxygen consumption: 167 ft^3/hr 
            MAPP gas:
                tip style: 
                feed rate: 14 .. 30 in/min
                removal rate: 90 in^3/hr
                fuel consumption: 15 ft^3/hr
                oxygen consumption: 120 ft^3/hr
        workpiece material:
            carbon steel:
                machinability:
                    typical: 3.3..3.7 stars
                    feasible: 3..4 stars
            cast iron:
                machinability:
                    feasible: 0.5..1.5 stars
                    typical: 0.8..1.2 stars
            galvanized steel:
                machinability:
                    feasible: 0 .. 1 stars
                    typical: 0.3 .. 0.6 stars
            free machining steel:
                machinability:
                    feasible: 0 .. 1 stars
                    typical: 0.3 .. 0.6 stars
    safety:
    -   hot parts
    -   toxic fumes
    -   sparks
    -   ultraviolet radiation
    -   flammable gases
    -   compressed gases
    -   smoke
    -   open flame
    -   explosive mixture

laser cutting: !process
    name: laser beam cutting
    classification: shaping, mass-reducing, thermal, high energy beam machining
    mechanism: focused coherent light heats workpiece to melting or vaporization, then shielding gas blows the melted material out of the cut
    geometry: 
        primitive: hyperboloid
        path: 
        -   parallel to workpiece face
        diameter: !which beam, diameter #hmmm. beam has no choices, i.e. this varies continuously
        tolerance:
            typical: +- 0.001in
            feasible: +- 0.0005in
    surface finish:
        typical: 125..250 microinch
        feasible: 100 .. 300 microinch
    consumables:
        cutting gas:
        power: !which workpiece material, power
    functionality: 
    -   drilling
    -   straight cuts
    -   irregular prismatic geometry
    -   !which lasing material, functionality
    effects:
    -   hardening
    -   annealing
    -   change in grain size
    parameters:
        beam: 
            focal length: 1.5 .. 3 in #this varies significantly with material thickness
            diameter:
                typical: 0.004 .. 0.0125 in
                feasible: 0.0002 .. 0.2 in
        workpiece thickness:
            feasible: 0.004 .. 6 inch
            typical: 0.02 .. 0.5 inch
        cutting gas:
            oxygen:
            compressed air:
            nitrogen:
            argon:
        feed rate: !which workpiece material, feed rate #over typical thickness range, feed rate
        workpiece reflectivity:
        workpiece thermal conductivity:
        workpiece material:
            aluminum:
                power: 1000 .. 10000 W
                feed rate: 30 .. 800 in/min
                machinability:
                    typical: 2.9..3.5 stars
                    feasible: 0.2 .. 3.8 stars
            stainless:
                power: 250 .. 1000 W
                feed rate: 20 .. 750 in/min
                machinability:
                    typical: 2.6..3.2 stars
                    feasible: 0.6 .. 3.6 stars
            mild steel:
                power: 400 .. 500 W
                feed rate: 40 .. 177 in/min
                machinability:
                    feasible: 2.5 .. 3.8 stars
                    typical: 2.9 .. 3.3 stars
            wood:
                power: 50 .. 650W
                feed rate: #45 .. 180 in/min #this is wrong, 180 refers to 0.25" thickness, paper must be faster
                machinability:
                    feasible: 2.3 .. 3.9 stars
                    typical: 2.9 .. 3.5 stars
            titanium:
                power: 210 .. 250 W
                feed rate: 40 .. 300 in/min
            plastic:
                feed rate: #25 .. 60 in/min #this is also wrong
                power: 50 .. 100W #i made this up
                machinability:
                    feasible: 2.1 .. 3.6 stars
                    typical: 2.6 .. 3.3 stars
        lasing material:
            CO2:
                functionality:
                -   scribing
                -   engraving 
            Nd: 
                functionality:
                -   high energy pulse
                -   low repetition speed #(1 KHz)#huh?
            Nd-YAG:
                functionality:
                -   very high energy pulse
                -   engraving
                -   trimming #wtf does this mean
    safety:
    -   coherent infrared radiation
    -   hot parts
    -   toxic fumes
    -   dust
    -   compressed gases
    
    
mig: !process
    name: MIG welding
    classification: shaping, joining, thermal, welding, electric arc, gas metal
    mechanism: a wire electrode surrounded by inert gas is heated to melting by an electric arc passing through it
    geometry:
        primitive: sphere
        post-operation: fillet edges
        diameter: !formula electrode rate*pi*(electrode diameter)^2/traverse rate #TODO unit check this formula
        tolerance: 
    surface finish:        
        typical: 250..1000 microinches
        feasible: 100..1100 microinches
    consumables:
        gas: !which shielding gas, flow rate
        electrode: !which weld geometry, feed rate
        power: !formula current * voltage
    functionality: !which shielding gas, functionality
    effects:
    -   hardening
    -   reduced fatigue strength
    -   shrinkage
    -   annealing
    -   warpage
    -   bad appearance
    -   cracks
    -   porosity
    -   reduced corrosion resistance
    weldability: !which workpiece material, weldability
    parameters:
        workpiece thickness:
            feasible: 0.02..2.5in
            typical: 0.125..1in
        electrode material:
            #usually similar to workpiece material
        filler material:
            manganese silicon:
                shielding gas: carbon dioxide
            aluminum:
                shielding gas: helium or argon
            steel:
                shielding gas: carbon dioxide
            powder core:
                functionality:
                -   specialized welding applications
            oxidizer:
                functionality:
                -   rusty surfaces
                -   semikilled steel
                -   rimmed steel #what's this?
        workpiece material:
            mild steel:
                weldability:
                    feasible: 2.4..3.7 stars
                    typical: 2.8..3.3 stars
            cast iron:
                weldability:
                    feasible: 1.3..3.1 stars
                    typical: 2.1..2.5 stars
            stainless:
                weldability:
                    feasible: 2.3..3.7 stars
                    typical: 2.7..3.2 stars
            aluminum:
                weldability:
                    feasible: 2.8..3.9 stars
                    typical: 3.2..3.7 stars
            copper:
                weldability:
                    feasible: 2.0..3.6 stars
                    typical: 2.6..2.95stars
            magnesium:
                weldability:
                    feasible: 2.6..3.6 stars
                    typical: 3.2..3.5 stars
            titanium:
                weldability:
                    feasible: 1.2..3.1 stars
                    typical: 1.9..2.5 stars
        shielding gas: #gases can be mixed.. how to represent this?
            argon:
                functionality:
                -   lower voltage
                -   high quality
                -   easy starting
                -   stable arc
            helium:
                functionality:
                -   high speed
                -   small heat affected zone
            carbon dioxide:
                functionality:
                -   good penetration
                -   low cost
                -   high speed
        weld geometry: #hmmm. i know it's in a book, but this is all wrong
            lap:
                traverse rate: 60ipm
                electrode rate: 234ipm
                electrode diameter: 0.0625in
                current: 380A
            butt:
                traverse rate: 7ipm
                electrode rate: 400ipm
                electrode diameter: 0.045in
                current: 275A
            tee:
                traverse rate: 16ipm
                electrode rate: 300ipm
                electrode diameter: 0.045in
                current: 200A
            edge:
                traverse rate: 
                electrode rate: 
                electrode diameter: 
            corner:
                traverse rate: 10ipm
                electrode rate: 30..160ipm
                electrode diameter: 0.030in
                current: 80..85A
            circumferential corner:
                traverse rate: 45ipm
                electrode rate: 500ipm
                electrode diameter: 0.045in
                current: 280..300A
            circumferential modified butt: #wtf is this
                traverse rate: 46.6ipm
                electrode rate: 340..380ipm
                electrode diameter: 0.030
                current: 170..190A
        current:
        voltage:
        traverse rate: !which weld geometry, traverse rate
        electrode rate: !which weld geometry, electrode rate
        electrode diameter: !which weld geometry, electrode diameter
    safety:
    -   UV radiation
    -   hot parts
    -   smoke
    -   sparks
    -   metal fumes