diff --git a/20151021/src/euslisp/kadai1.l b/20151021/src/euslisp/kadai1.l
new file mode 100644
index 00000000..e956aef0
--- /dev/null
+++ b/20151021/src/euslisp/kadai1.l
@@ -0,0 +1,24 @@
+(if (not (boundp '*irtviewer*)) (make-irtviewer))
+
+(setq sun (make-sphere 100))
+(send sun :set-color :red)
+
+(setq earth (make-sphere 10))
+(send earth :set-color :blue)
+
+(setq moon (make-sphere 2))
+(send moon :set-color :yellow)
+
+(send earth :locate #f(200 0 0))
+
+(send sun :assoc earth)
+(send earth :assoc moon)
+(send moon :locate #f(250 0 0))
+
+(objects (list sun earth moon))
+
+(do-until-key
+ (send sun :rotate (deg2rad 5) :z)
+ (send earth :rotate (deg2rad 10) :z)
+ (send *irtviewer* :draw-objects)
+)
diff --git a/20151021/src/euslisp/kadai2.l b/20151021/src/euslisp/kadai2.l
new file mode 100644
index 00000000..b13bf66e
--- /dev/null
+++ b/20151021/src/euslisp/kadai2.l
@@ -0,0 +1,37 @@
+;;(if (not (boundp '*irtviewer*)) (make-irtviewer))
+
+(defun make-piston-cylinder nil
+  (let (b1 b2)
+    (setq b1 (make-cylinder 10 50))
+    (send b1 :locate #f(0 0 0))
+    (setq b2 (make-cylinder 6 50))
+    (send b2 :locate #f(0 0 0))
+    (setq b1 (body- b1 b2))
+    (send b1 :set-color :red)
+    b1))
+
+(defun make-piston nil 
+  (let (b1 b2 b3 b4 b5)
+    (setq b1 (make-cylinder 7.9 15 ))
+    (setq b2 (make-cylinder 2 10))
+    (send b2 :locate #f(0 0 15))
+    (setq b3 (make-cube 6 10 2))
+    (send b3 :locate #f(0 0 25))
+    (setq b4 (body+ b1 b2))
+    (send b3 :set-color :gray80)
+    (send b4 :set-color :white)
+    (setq b5 (body+ b3 b4))
+    b5))
+    
+
+(setq c1 (instance bodyset-link :init (make-cascoords) :bodies (list (make-piston-cylinder))))
+(setq p1 (instance bodyset-link :init (make-cascoords) :bodies (list (make-piston))))
+(setq a1 (instance rotational-joint :init :parent-link c1 :child-link p1 :axis :z))
+
+(setq r (instance cascaded-link :init))
+(send r :assoc c1)
+(send c1 :assoc p1)
+(setq (r . links) (list c1 p1))
+(setq (r . joint-list) (list a1))
+(send r :init-ending)
+