diff --git a/2019/sketch_190517b/ensamble.py b/2019/sketch_190517b/ensamble.py
new file mode 100644
index 00000000..ed77daee
--- /dev/null
+++ b/2019/sketch_190517b/ensamble.py
@@ -0,0 +1,28 @@
+from random import choice
+from polys import poly, poly_arc_augmented
+
+
+class Ensamble:
+    
+
+    def __init__(self, points, radius):
+        self.p_list = points
+        self.rad_list = radius
+        
+    def __eq__(self, other):
+        return self.p_list == other.p_list
+
+    def plot(self):
+        rad_list = self.rad_list
+        noFill()
+        # strokeWeight(10)
+        # stroke(0, 100, 200)
+        # strokeJoin(ROUND)
+        # poly(self.p_list)
+        strokeWeight(10)
+        for i in range(len(rad_list)):
+            colorMode(HSB)
+            stroke(i 8, 255, 255)
+            poly_arc_augmented(self.p_list, rad_list)
+            rad_list[:] = [rad_list[-1]] + rad_list[:-1]
+ 
diff --git a/2019/sketch_190517b/gif_exporter.py b/2019/sketch_190517b/gif_exporter.py
new file mode 100644
index 00000000..e908a2f1
--- /dev/null
+++ b/2019/sketch_190517b/gif_exporter.py
@@ -0,0 +1,43 @@
+"""
+Alexandre B A Villares http://abav.lugaralgum.com - GPL v3 
+
+A helper for the Processing gifAnimation library (https://github.com/jordanorelli)
+ported to Processing 3 by 01010101 (https://github.com/01010101)
+Download the library from https://github.com/01010101/GifAnimation/archive/master.zip
+This helper was inspired by an example by Art Simon https://github.com/APCSPrinciples/AnimatedGIF/
+
+Put  at the start of your sketch:
+   add_library('gifAnimation')
+   from gif_exporter import gif_export
+and at the end of draw():
+    gif_export(GifMaker)
+"""
+
+def gif_export(GifMaker,             # gets a reference to the library
+               filename="exported",  # .gif will be added
+               repeat=0,             # 0 makes it an "endless" animation
+               quality=182,          # quality range 0 - 255
+               delay=170,            # this is quick
+               frames=0):            # 0 will stop on keyPressed or frameCount >= 100000
+    global gifExporter
+    try:
+        gifExporter
+    except NameError:
+        gifExporter = GifMaker(this, filename + ".gif")
+        gifExporter.setRepeat(repeat)
+        gifExporter.setQuality(quality)
+        gifExporter.setDelay(delay)
+        gif_export._frame = frameCount
+        print("gif start")
+
+    gifExporter.addFrame()
+
+    # if (frames == 0 and keyPressed or frameCount - gif_export._frame >= 100000) \
+    #         or (frames != 0 and frameCount - gif_export._frame >= frames):
+    #     gifExporter.finish()
+    #     background(255)
+    #     print("gif saved")
+    #     del(gifExporter)
+    #     return False
+    # else:
+    #     return True
diff --git a/2019/sketch_190517b/polys.py b/2019/sketch_190517b/polys.py
new file mode 100644
index 00000000..69e3f489
--- /dev/null
+++ b/2019/sketch_190517b/polys.py
@@ -0,0 +1,60 @@
+# -*- coding: utf-8 -*-
+
+def poly(p_list, closed=True):
+    beginShape()
+    for p in p_list:
+        if p[2] == 0:
+            vertex(p[0], p[1])
+        else:
+            vertex(*p)
+    if closed:
+        endShape(CLOSE)
+    else:
+        endShape()
+
+def poly_arc_augmented(p_list, r_list):
+    a_list = []
+    for i1 in range(len(p_list)):
+        i2 = (i1 + 1) % len(p_list)
+        p1, p2, r1, r2 = p_list[i1], p_list[i2], r_list[i1], r_list[i2]
+        a = circ_circ_tangent(p1, p2, r1, r2)
+        a_list.append(a)
+        # ellipse(p1.x, p1.y, 2, 2)
+
+    for i1 in range(len(a_list)):
+        i2 = (i1 + 1) % len(a_list)
+        p1, p2, r1, r2 = p_list[i1], p_list[i2], r_list[i1], r_list[i2]
+        #ellipse(p1.x, p1.y, r1 * 2, r1 * 2)
+        a1 = a_list[i1]
+        a2 = a_list[i2]
+        if a1 and a2:
+            start = a1 if a1 < a2 else a1 - TWO_PI
+            arc(p2.x, p2.y, r2 * 2, r2 * 2, start, a2)
+        else:
+            # println((a1, a2))
+            ellipse(p1.x, p1.y, r1 * 2, r1 * 2)
+            ellipse(p2.x, p2.y, r2 * 2, r2 * 2)
+
+
+def circ_circ_tangent(p1, p2, r1, r2):
+    d = dist(p1.x, p1.y, p2.x, p2.y)
+    ri = r1 - r2
+    line_angle = atan2(p1.x - p2.x, p2.y - p1.y)
+    if d > abs(ri):
+        theta = asin(ri / float(d))
+
+        x1 = cos(line_angle - theta) * r1
+        y1 = sin(line_angle - theta) * r1
+        x2 = cos(line_angle - theta) * r2
+        y2 = sin(line_angle - theta) * r2
+        # line(p1.x - x1, p1.y - y1, p2.x - x2, p2.y - y2)
+
+        x1 = -cos(line_angle + theta) * r1
+        y1 = -sin(line_angle + theta) * r1
+        x2 = -cos(line_angle + theta) * r2
+        y2 = -sin(line_angle + theta) * r2
+        line(p1.x - x1, p1.y - y1, p2.x - x2, p2.y - y2)
+        return (line_angle + theta)
+    else:
+        line(p1.x, p1.y, p2.x, p2.y)
+        return None
diff --git a/2019/sketch_190517b/s190512a.gif b/2019/sketch_190517b/s190512a.gif
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index 00000000..3d528b6f
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diff --git a/2019/sketch_190517b/sketch_190517a.gif b/2019/sketch_190517b/sketch_190517a.gif
new file mode 100644
index 00000000..1438ae94
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diff --git a/2019/sketch_190517b/sketch_190517b.gif b/2019/sketch_190517b/sketch_190517b.gif
new file mode 100644
index 00000000..9993e7dd
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diff --git a/2019/sketch_190517b/sketch_190517b.pyde b/2019/sketch_190517b/sketch_190517b.pyde
new file mode 100644
index 00000000..5c3da4c5
--- /dev/null
+++ b/2019/sketch_190517b/sketch_190517b.pyde
@@ -0,0 +1,88 @@
+# Alexandre B A Villares - https://abav.lugaralgum.com/sketch-a-day
+from __future__ import division
+from random import choice
+from ensamble import Ensamble
+
+add_library('GifAnimation')
+from gif_exporter import gif_export
+
+SPACING, MARGIN = 100, 250
+grid = []
+N = 8
+
+combinations = ((0, 1, 2), (0, 1, 3), (0, 1, 4), (0, 1, 5),
+                (0, 1, 6), (0, 1, 7), (0, 2, 3), (0, 2, 4),
+                (0, 2, 5), (0, 2, 6), (0, 2, 7), (0, 3, 4),
+                (0, 3, 5), (0, 3, 6), (0, 3, 7), (0, 4, 5),
+                (0, 4, 6), (0, 4, 7), (0, 5, 6), (0, 5, 7),
+                (0, 6, 7), (1, 2, 3), (1, 2, 4), (1, 2, 5),
+                (1, 2, 6), (1, 2, 7), (1, 3, 4), (1, 3, 5),
+                (1, 3, 6), (1, 3, 7), (1, 4, 5), (1, 4, 6),
+                (1, 4, 7), (1, 5, 6), (1, 5, 7), (1, 6, 7),
+                (2, 3, 4), (2, 3, 5), (2, 3, 6), (2, 3, 7),
+                (2, 4, 5), (2, 4, 6), (2, 4, 7), (2, 5, 6),
+                (2, 5, 7), (2, 6, 7), (3, 4, 5), (3, 4, 6),
+                (3, 4, 7), (3, 5, 6), (3, 5, 7), (3, 6, 7),
+                (4, 5, 6), (4, 5, 7), (4, 6, 7), (5, 6, 7))
+def setup():
+    global grid_list, rad_list
+    size(700, 700)
+    W, H = 700, 700
+    X_LIST = [x for x in range(MARGIN, 1 + W - MARGIN, SPACING)]
+    Y_LIST = [y for y in range(MARGIN, 1 + H - MARGIN, SPACING)]
+    print X_LIST
+    grid_list = []
+    for x in X_LIST:
+        for y in Y_LIST:
+            grid_list.append((x, y))
+    grid_list.pop(len(grid_list) // 2)
+    rad_list = [20, 40, 60, 80, 100, 120, 140, 160] 
+    
+    create_grid(grid_list, rad_list)
+    
+    
+
+def create_grid(grid_list, rad_list):
+
+    for a, b, c in combinations:
+        va = PVector(*grid_list[a])
+        vb = PVector(*grid_list[b])
+        vc = PVector(*grid_list[c])
+        e = Ensamble((va, vb, vc), [rad_list[a], rad_list[b], rad_list[c]])
+        grid.append(e)
+
+def draw():
+    translate(0, 50)
+    scale(1 / N, 1 / N)
+    background(250, 250, 240)
+    for x in range(N):
+        for y in range(N):
+            pushMatrix()
+            translate(x * 700, y * 700)
+            if x + y * N < 56:
+                grid[x + y * N].plot()
+            popMatrix()
+
+
+def keyPressed():
+    if key == " ":
+        grid[:] = []
+        rad_list[:] = rad_list[1::]+[rad_list[0]]
+        create_grid(grid_list, rad_list)
+    if key == "s":
+        saveFrame("###.png")
+    if key == "g":
+        gif_export(GifMaker, filename=SKETCH_NAME, delay=1200)
+
+def settings():
+    from os import path
+    global SKETCH_NAME
+    SKETCH_NAME = path.basename(sketchPath())
+    OUTPUT = ".gif"
+    println(
+        """
+![{0}]({2}/{0}/{0}{1})
+
+[{0}](https://github.com/villares/sketch-a-day/tree/master/{2}/{0}) [[Py.Processing](https://villares.github.io/como-instalar-o-processing-modo-python/index-EN)]
+""".format(SKETCH_NAME, OUTPUT, year())
+    )