diff --git a/dustcover.go b/dustcover.go
index 7eeb093..2bba184 100644
--- a/dustcover.go
+++ b/dustcover.go
@@ -5,9 +5,11 @@ import (
 	"github.com/deadsy/sdfx/sdf"
 )
 
-const DUST_COVER_OUTER_CIRCUM = 37.5
-const DUST_COVER_INNER_CIRCUM = 14.0
-const DUST_COVER_HEIGHT = 1.48
+const (
+	DUST_COVER_OUTER_CIRCUM = 37.5
+	DUST_COVER_INNER_CIRCUM = 14.0
+	DUST_COVER_HEIGHT       = 1.48
+)
 
 func dustCover() (sdf.SDF3, error) {
 	cutoutHeight := 0.16
diff --git a/insert.go b/insert.go
index 7315d16..2325290 100644
--- a/insert.go
+++ b/insert.go
@@ -4,8 +4,10 @@ import (
 	"github.com/deadsy/sdfx/sdf"
 )
 
-const INSERT_SIZE_CIRCUM = 8.5
-const INSERT_SIZE_HEIGHT = 13.0
+const (
+	INSERT_SIZE_CIRCUM = 8.5
+	INSERT_SIZE_HEIGHT = 13.0
+)
 
 func Insert() (sdf.SDF3, error) {
 	return sdf.Cylinder3D(INSERT_SIZE_HEIGHT, INSERT_SIZE_CIRCUM/2, 0)
diff --git a/main.go b/main.go
index 995f903..a2f7e71 100644
--- a/main.go
+++ b/main.go
@@ -8,7 +8,9 @@ func main() {
 	insert, _ := Insert()
 	balltop, _ := balltop()
 	dustCover, _ := dustCover()
+	shaftCover, _ := shaftCover()
 	render.RenderSTL(insert, 300, "insert.stl")
 	render.RenderSTL(balltop, 300, "balltop.stl")
 	render.RenderSTL(dustCover, 300, "dustcover.stl")
+	render.RenderSTL(shaftCover, 300, "shaftcover.stl")
 }
diff --git a/shaftcover.go b/shaftcover.go
new file mode 100644
index 0000000..3044b15
--- /dev/null
+++ b/shaftcover.go
@@ -0,0 +1,24 @@
+package main
+
+import "github.com/deadsy/sdfx/sdf"
+
+const (
+	SHAFT_GIRTH         = 1.6
+	SHAFT_OUTTER_CIRCUM = 11.7
+	SHAFT_INNER_CIRCUM  = 9.4
+	SHAFT_HEIGHT        = 35.0
+)
+
+func shaftCover() (sdf.SDF3, error) {
+	sleeve, err := sdf.Circle2D(SHAFT_OUTTER_CIRCUM / 2)
+	if err != nil {
+		return Error(err)
+	}
+	hole, err := sdf.Circle2D(SHAFT_INNER_CIRCUM / 2)
+	if err != nil {
+		return Error(err)
+	}
+	shaft := sdf.Difference2D(sleeve, hole)
+
+	return sdf.Extrude3D(shaft, SHAFT_HEIGHT), nil
+}