func Plot(g1, g2 gear.Gear, rotfrac int, fname string) {
var width, height int
border := 5.0
if g1.Pd > g2.Pd {
height = int(g1.GetOutsideDia() + (2 * border))
} else {
height = int(g2.GetOutsideDia() + (2 * border))
}
width = int((g1.Pd + g2.Pd + g1.GetAddendum() + g2.GetAddendum()) + (2 * border))
centerDist := (g1.Pd + g2.Pd) / 2
cx := int((border + (g1.GetOutsideDia() / 2.0)) * factor)
cy := height * factor / 2
var canvas *svg.SVG
var f *os.File
var err error
if fname != "" {
f, err = os.Create(fmt.Sprintf("%s.svg", fname))
if err != nil {
fmt.Println("Something failed creating file!")
}
canvas = svg.New(f)
} else {
canvas = svg.New(os.Stdout)
}
// Setup canvas so that each drawing unit is 0.01mm.
canvas.StartviewUnit(width, height, "mm", 0, 0, width*factor, height*factor)
plotGrid(cx, cy, width*factor, height*factor, canvas)
rot := 0.0 + ((float64(rotfrac) / 100) * (360 / float64(g1.N)))
plotGear(cx, cy, rot, g1, canvas)
cx = cx + int(centerDist*factor)
if math.Mod(float64(g2.N), 2) == 0 {
rot = 180.0 / float64(g2.N)
} else {
rot = 0.0
}
rot -= (float64(rotfrac) / 100) * (360 / float64(g2.N))
plotGear(cx, cy, rot, g2, canvas)
// canvas.Text(width *100 /2, height * 100 /2, "Hello, SVG", "text-anchor:middle;font-size:300;fill:black")
canvas.End()
if f != nil {
f.Sync()
f.Close()
}
}
func main() {
var Centres float64 // Distance between Centres
var Ratio float64 // Required Ratio
var DriveTeeth int // Number of teeth on drive gear
var DrivenTeeth int // Number of teeth on drive gear
var PressureAngle float64
var Backlash float64
var Rotation int // Percent of rotation
var FileName string // File name for output.
var pCentres = flag.Int("c", 100, "Distance between centres. (Whole mm only)")
var pDriveTeeth = flag.Int("n1", 7, "Number of teeth on the first gear")
var pDrivenTeeth = flag.Int("n2", 23, "Number of teeth on the second gear")
var pPressureAngle = flag.Int("p", 25, "Pressure angle")
var pBacklash = flag.String("b", "0.5", "Backlash angle (degrees)")
var pFileName = flag.String("o", "", "Output file name, .svg will be appended. stdout if not given")
var pRotation = flag.Int("r", 0, "Rotation as percentage of one tooth")
flag.Parse()
Centres = float64(*pCentres)
DriveTeeth = *pDriveTeeth
DrivenTeeth = *pDrivenTeeth
PressureAngle = float64(*pPressureAngle)
var err error
Backlash, err = strconv.ParseFloat(*pBacklash, 64)
if err != nil {
Backlash = 0.0
}
Rotation = *pRotation
FileName = *pFileName
Ratio = float64(DrivenTeeth) / float64(DriveTeeth)
var Gear1 gear.Gear
Gear1.Pd = (1 / (Ratio + 1)) * Centres * 2
Gear1.N = DriveTeeth
Gear1.A = PressureAngle
Gear1.B = Backlash
var Gear2 gear.Gear
Gear2.Pd = (Ratio / (Ratio + 1)) * Centres * 2
Gear2.N = DrivenTeeth
Gear2.A = PressureAngle
Gear2.B = Backlash
plot.Plot(Gear1, Gear2, Rotation, FileName)
}
func plotGear(cx int, cy int, rot float64, g gear.Gear, canvas *svg.SVG) {
canvas.Gtransform(fmt.Sprintf("translate(%d, %d)", cx, cy))
canvas.Circle(0, 0, int(g.Pd*factor/2), style("dash"))
cntrLen := int(g.GetOutsideDia() * factor / 8)
canvas.Line(-cntrLen, 0, cntrLen, 0, style("solid"))
canvas.Line(0, -cntrLen, 0, cntrLen, style("solid"))
canvas.Gtransform(fmt.Sprintf("rotate(%0.3f)", rot))
for i := 0; i < g.N; i++ {
canvas.Line(int((math.Cos((360/float64(g.N))*float64(i)*DegToRad) * g.GetRootCircleDia() * factor / 2)),
int((math.Sin((360/float64(g.N))*float64(i)*DegToRad) * g.GetRootCircleDia() * factor / 2)),
int((math.Cos((360/float64(g.N))*float64(i)*DegToRad) * g.GetOutsideDia() * factor / 2)),
int((math.Sin((360/float64(g.N))*float64(i)*DegToRad) * g.GetOutsideDia() * factor / 2)),
style("dash"))
canvas.Gtransform(fmt.Sprintf("rotate(%f)", 360.0/float64(g.N)*float64(i)))
plotInvCurve(g, canvas)
canvas.Gend()
}
canvas.Gend()
canvas.Gend()
}
func plotInvCurve(g gear.Gear, canvas *svg.SVG) {
var px []int
var py []int
var pyi []int
var x, y float64
var r, sr, ang float64
var offsetAng float64
br := g.GetBaseCircleDia() * factor / 2 // Base Radius
or := g.GetOutsideDia() * factor / 2 // Outside Radius
rr := g.GetRootCircleDia() * factor / 2 // Root Radius
pr := g.Pd * factor / 2 // Pitch Circle Radius
ang = involuteIntersectAngle(br, pr)
x, y = xyLocation(br, ang)
offsetAng = math.Atan(y/x) * -1
offsetAng += (math.Pi / (float64(g.N) / 2.0)) / -4.0
if rr > br {
sr = rr
} else {
sr = br
}
rinc := (or - sr) / 100
for r = sr; r <= or; r += rinc {
ang = involuteIntersectAngle(br, r)
x, y = xyLocation(br, ang)
px = append(px, int(x))
py = append(py, int(y))
pyi = append(pyi, int(y)*-1)
}
if br > rr {
px = append([]int{int(rr)}, px...)
py = append([]int{0}, py...)
pyi = append([]int{0}, pyi...)
}
canvas.Gtransform(fmt.Sprintf("rotate(%0.4f)", offsetAng*RadToDeg))
canvas.Polyline(px, py, style("solid"))
canvas.Gend()
canvas.Gtransform(fmt.Sprintf("rotate(%0.4f)", offsetAng*RadToDeg*-1.0))
canvas.Polyline(px, pyi, style("solid"))
canvas.Gend()
sx, sy := rotXY(px[len(px)-1], py[len(py)-1], offsetAng)
ex, ey := rotXY(px[len(px)-1], pyi[len(pyi)-1], offsetAng*-1.0)
canvas.Path(fmt.Sprintf("M%d,%d A%d,%d 0 0 1 %d,%d",
sx, sy, int(or), int(or),
ex, ey), style("solid"))
sx, sy = rotXY(px[0], py[0], -offsetAng)
ex, ey = rotXY(px[0], py[0], ((2*math.Pi)/float64(g.N))+offsetAng)
canvas.Path(fmt.Sprintf("M%d,%d A%d,%d 0 0 1 %d,%d",
sx, sy, int(rr), int(rr),
ex, ey), style("solid"))
}