diff --git a/libtest.png b/libtest.png
index 75cab67..1cd6271 100644
Binary files a/libtest.png and b/libtest.png differ
diff --git a/libtest.scad b/libtest.scad
index 73cbc4b..43c47be 100644
--- a/libtest.scad
+++ b/libtest.scad
@@ -33,6 +33,7 @@ use <tests/components.scad>
 use <tests/d_connectors.scad>
 use <tests/displays.scad>
 use <tests/extrusions.scad>
+use <tests/extrusion_brackets.scad>
 use <tests/fans.scad>
 use <tests/fuseholder.scad>
 use <tests/geared_steppers.scad>
@@ -40,6 +41,7 @@ use <tests/hot_ends.scad>
 use <tests/iecs.scad>
 use <tests/inserts.scad>
 use <tests/jack.scad>
+use <tests/kp_pillow_blocks.scad>
 use <tests/leadnuts.scad>
 use <tests/leds.scad>
 use <tests/ldrs.scad>
@@ -60,8 +62,10 @@ use <tests/ring_terminals.scad>
 use <tests/rockers.scad>
 use <tests/rod.scad>
 use <tests/screws.scad>
+use <tests/scs_bearing_blocks.scad>
 use <tests/sealing_strip.scad>
 use <tests/sheets.scad>
+use <tests/sk_brackets.scad>
 use <tests/spades.scad>
 use <tests/springs.scad>
 use <tests/ssrs.scad>
@@ -94,7 +98,13 @@ use <tests/psu_shroud.scad>
 use <tests/flat_hinge.scad>
 use <tests/pcb_mount.scad>
 
-x5 = 800;
+x0 = 0;
+x1 = x0 + 100;
+x2 = x1 + 90;
+x3 = x2 + 130;
+x4 = x3 + 200;
+x5 = 850;
+x6 = x5 + 150;
 
 cable_grommets_y = 0;
 
@@ -133,13 +143,12 @@ translate([x5 + 60, cable_grommets_y + 200])
 translate([x5, cable_grommets_y + 250])
     handle();
 
-translate([900, 600])
+translate([950, 600])
     box_test();
 
 translate([850, 1260])
     bbox_test();
 
-x0 = 0;
 inserts_y = 0;
 nuts_y = inserts_y + 20;
 washers_y = nuts_y + 100;
@@ -204,10 +213,6 @@ translate([x0, linear_bearings_y]) {
     rods();
 }
 
-translate([x0+150, linear_bearings_y+30]) {
-    extrusions();
-}
-
 translate([x0 + 10, hot_ends_y])
     hot_ends();
 
@@ -236,7 +241,6 @@ translate([x0, psus_y]) {
     psu_shrouds();
 }
 
-x1 = x0 + 100;
 zipties_y = 0;
 bulldogs_y = zipties_y + 40;
 
@@ -246,7 +250,6 @@ translate([x1, zipties_y])
 translate([x1, bulldogs_y])
     bulldogs();
 
-x2 = x1 + 90;
 leds_y = 0;
 carriers_y = leds_y + 40;
 spades_y = carriers_y + 40;
@@ -293,8 +296,6 @@ translate([x2, toggles_y])
 translate([x2, components_y])
     components();
 
-
-x3 = x2 + 150;
 veroboard_y = 0;
 d_connectors_y = veroboard_y + 110;
 iecs_y = d_connectors_y + 80;
@@ -303,6 +304,7 @@ ssrs_y = modules_y + 80;
 blowers_y = ssrs_y + 60;
 batteries_y = blowers_y + 100;
 steppers_y = batteries_y + 70;
+extrusions_y = steppers_y + 100;
 
 translate([x3, veroboard_y])
     veroboard_test();
@@ -343,16 +345,22 @@ translate([x3, batteries_y])
 translate([x2, steppers_y])  // interloper
     stepper_motors();
 
+translate([x2, extrusions_y]) {
+    extrusions();
+}
+
 translate([x3, transformers_y])
     transformers();
 
 
-x4 = x3 + 220;
 belts_y = 0;
 rails_y = belts_y + 200;
-cable_strips_y = rails_y + 300;
+extrusion_brackets_y = rails_y + 250;
+sk_brackets_y = extrusion_brackets_y + 80;
+kp_pillow_blocks_y = sk_brackets_y + 50;
+scs_bearing_blocks_y = kp_pillow_blocks_y + 60;
 
-translate([x4 + 112, belts_y + 58]) {
+translate([x4 + 130, belts_y + 58]) {
     belt_test();
 
     translate([0, 60])
@@ -362,9 +370,22 @@ translate([x4 + 112, belts_y + 58]) {
 translate([x4, rails_y + 130])
     rails();
 
-translate([x4, cable_strips_y])
-    cable_strips();
+translate([780, 0])
+    rotate(90)
+        cable_strips();
+
+translate([x4, kp_pillow_blocks_y])
+    kp_pillow_blocks();
+
+translate([x4, sk_brackets_y])
+    sk_brackets();
+
+translate([x4, extrusion_brackets_y])
+    extrusion_brackets();
+
+translate([x4, scs_bearing_blocks_y])
+    scs_bearing_blocks();
+
 
-x6 = x5 + 150;
 translate([x6, 125])
     light_strips();
diff --git a/readme.md b/readme.md
index fea22b4..5675b89 100644
--- a/readme.md
+++ b/readme.md
@@ -626,10 +626,10 @@ Brackets for joining extrusions at a corner.
 ### Vitamins
 | Qty | Module call | BOM entry |
 | ---:|:--- |:---|
-|   1 | ```extrusion(E2020, 20, false)``` |  Extrusion E2020 x 20mm |
-|   1 | ```extrusion(E2020, 30, false)``` |  Extrusion E2020 x 30mm |
-|   1 | ```extrusion(E2020, 40, false)``` |  Extrusion E2020 x 40mm |
-|   1 | ```extrusion(E2020, 50, false)``` |  Extrusion E2020 x 50mm |
+|   1 | ```extrusion(E2020, 20)``` |  Extrusion E2020 x 20mm |
+|   1 | ```extrusion(E2020, 30)``` |  Extrusion E2020 x 30mm |
+|   1 | ```extrusion(E2020, 40)``` |  Extrusion E2020 x 40mm |
+|   1 | ```extrusion(E2020, 50)``` |  Extrusion E2020 x 50mm |
 |   2 | ```extrusion_corner_bracket(E20_corner_bracket)``` |  Extrusion corner bracket 20 |
 |   2 | ```extrusion_inner_corner_bracket(E20_inner_corner_bracket, true)``` |  Extrusion inner corner bracket 4.5 |
 |   1 | ```extrusion_inner_corner_bracket(E20_inner_corner_bracket, false)``` |  Extrusion inner corner bracket 4.5 |
@@ -669,21 +669,21 @@ Aluminium  extrusion.
 ### Modules
 | Module | Description |
 |:--- |:--- |
-| ```extrusion(type, length, center = false, cornerHole = false)``` | Draw the specified extrusion |
+| ```extrusion(type, length, center = true, cornerHole = false)``` | Draw the specified extrusion |
 
 ![extrusions](tests/png/extrusions.png)
 
 ### Vitamins
 | Qty | Module call | BOM entry |
 | ---:|:--- |:---|
-|   1 | ```extrusion(E2020, 80, false)``` |  Extrusion E2020 x 80mm |
-|   1 | ```extrusion(E2040, 80, false)``` |  Extrusion E2040 x 80mm |
-|   1 | ```extrusion(E2060, 80, false)``` |  Extrusion E2060 x 80mm |
-|   1 | ```extrusion(E2080, 80, false)``` |  Extrusion E2080 x 80mm |
-|   1 | ```extrusion(E3030, 80, false)``` |  Extrusion E3030 x 80mm |
-|   1 | ```extrusion(E3060, 80, false)``` |  Extrusion E3060 x 80mm |
-|   1 | ```extrusion(E4040, 80, false)``` |  Extrusion E4040 x 80mm |
-|   1 | ```extrusion(E4080, 80, false)``` |  Extrusion E4080 x 80mm |
+|   1 | ```extrusion(E2020, 80)``` |  Extrusion E2020 x 80mm |
+|   1 | ```extrusion(E2040, 80)``` |  Extrusion E2040 x 80mm |
+|   1 | ```extrusion(E2060, 80)``` |  Extrusion E2060 x 80mm |
+|   1 | ```extrusion(E2080, 80)``` |  Extrusion E2080 x 80mm |
+|   1 | ```extrusion(E3030, 80)``` |  Extrusion E3030 x 80mm |
+|   1 | ```extrusion(E3060, 80)``` |  Extrusion E3060 x 80mm |
+|   1 | ```extrusion(E4040, 80)``` |  Extrusion E4040 x 80mm |
+|   1 | ```extrusion(E4080, 80)``` |  Extrusion E4080 x 80mm |
 
 
 <a href="#top">Top</a>
@@ -2008,15 +2008,13 @@ PCBs and perfboard with optional components. The shape can be a rectangle with o
 |   1 | ```pcb(RPI0)``` |  Raspberry Pi Zero |
 |  16 | ```screw(M2_cap_screw, 25)``` |  Screw M2 cap x 25mm |
 |   4 | ```screw(M2p5_cap_screw, 16)``` |  Screw M2.5 cap x 16mm |
-|   8 | ```screw(M2p5_cap_screw, 20)``` |  Screw M2.5 cap x 20mm |
-|   4 | ```screw(M2p5_cap_screw, 35)``` |  Screw M2.5 cap x 35mm |
-|   8 | ```screw(M2p5_pan_screw, 20)``` |  Screw M2.5 pan x 20mm |
-|   4 | ```screw(M2p5_pan_screw, 25)``` |  Screw M2.5 pan x 25mm |
+|  12 | ```screw(M2p5_cap_screw, 20)``` |  Screw M2.5 cap x 20mm |
+|   4 | ```screw(M2p5_pan_screw, 20)``` |  Screw M2.5 pan x 20mm |
+|   8 | ```screw(M2p5_pan_screw, 25)``` |  Screw M2.5 pan x 25mm |
 |   4 | ```screw(M2p5_pan_screw, 35)``` |  Screw M2.5 pan x 35mm |
 |   8 | ```screw(M3_cap_screw, 30)``` |  Screw M3 cap x 30mm |
 |   4 | ```screw(M3_cap_screw, 35)``` |  Screw M3 cap x 35mm |
-|   4 | ```screw(M4_cap_screw, 30)``` |  Screw M4 cap x 30mm |
-|   8 | ```screw(M4_cap_screw, 35)``` |  Screw M4 cap x 35mm |
+|  12 | ```screw(M4_cap_screw, 35)``` |  Screw M4 cap x 35mm |
 |   3 | ```terminal_35(2)``` |  Terminal block 2 way 3.5mm |
 |   2 | ```green_terminal(gt_2p54, 4)``` |  Terminal block 4 way 0.1" |
 |   1 |  |  USB A to Mini B lead |
@@ -2029,24 +2027,24 @@ PCBs and perfboard with optional components. The shape can be a rectangle with o
 ### Printed
 | Qty | Filename |
 | ---:|:--- |
-|   4 | pcb_spacer20130.stl |
 |   4 | pcb_spacer20140.stl |
 |   4 | pcb_spacer20150.stl |
 |   4 | pcb_spacer20160.stl |
-|   4 | pcb_spacer25100_2.stl |
+|   4 | pcb_spacer20170.stl |
+|   4 | pcb_spacer25100.stl |
 |   4 | pcb_spacer25110_2.stl |
 |   4 | pcb_spacer25120_2.stl |
-|   4 | pcb_spacer25230.stl |
+|   4 | pcb_spacer25130_2.stl |
 |   4 | pcb_spacer25240.stl |
-|   4 | pcb_spacer2570.stl |
+|   4 | pcb_spacer2550.stl |
 |   4 | pcb_spacer2580.stl |
 |   4 | pcb_spacer2590.stl |
-|   4 | pcb_spacer30170.stl |
 |   4 | pcb_spacer30180.stl |
-|   4 | pcb_spacer30220.stl |
-|   4 | pcb_spacer40190.stl |
+|   4 | pcb_spacer30190.stl |
+|   4 | pcb_spacer30230.stl |
 |   4 | pcb_spacer40200.stl |
 |   4 | pcb_spacer40210.stl |
+|   4 | pcb_spacer40220.stl |
 
 
 <a href="#top">Top</a>
@@ -2603,6 +2601,9 @@ Machine screws and wood screws with various head styles.
 ---
 <a name="Scs_bearing_blocks"></a>
 ## Scs_bearing_blocks
+SCSnUU and SCSnLUU bearing blocks
+
+
 [vitamins/scs_bearing_blocks.scad](vitamins/scs_bearing_blocks.scad) Object definitions.
 
 [vitamins/scs_bearing_block.scad](vitamins/scs_bearing_block.scad) Implementation.
@@ -2784,8 +2785,8 @@ SK shaft support brackets
 ### Vitamins
 | Qty | Module call | BOM entry |
 | ---:|:--- |:---|
-|   2 | ```extrusion(E2020, 20, false)``` |  Extrusion E2020 x 20mm |
-|   2 | ```extrusion(E3030, 20, false)``` |  Extrusion E3030 x 20mm |
+|   2 | ```extrusion(E2020, 20)``` |  Extrusion E2020 x 20mm |
+|   2 | ```extrusion(E3030, 20)``` |  Extrusion E3030 x 20mm |
 |   2 | ```sliding_t_nut(M4_hammer_nut)``` |  Nut M4 hammer |
 |   2 | ```sliding_t_nut(M4_sliding_t_nut)``` |  Nut M4 sliding T |
 |   2 | ```sliding_t_nut(M5_sliding_t_nut)``` |  Nut M5 sliding T |
diff --git a/tests/extrusion_brackets.scad b/tests/extrusion_brackets.scad
index d43d11b..4432067 100644
--- a/tests/extrusion_brackets.scad
+++ b/tests/extrusion_brackets.scad
@@ -23,7 +23,7 @@ include <../vitamins/extrusions.scad>
 include <../vitamins/washers.scad>
 include <../vitamins/nuts.scad>
 
-module extrusion_brackets() {
+module extrusion_brackets(examples = false) {
     extrusion_inner_corner_bracket(E20_inner_corner_bracket);
 
     translate([30, 0])
@@ -34,27 +34,32 @@ module extrusion_brackets() {
 
     eWidth = extrusion_width(E2020);
 
-    translate([0, 60]) {
-        extrusion_inner_corner_bracket(E20_inner_corner_bracket);
-        translate([-eWidth / 2, 0, 0])
-            rotate([-90, 0, 0])
-                extrusion(E2020, 20);
-        translate([-eWidth, -eWidth / 2, 0])
-            rotate([0, 90, 0])
-                extrusion(E2020, 40);
-    }
+    if(examples) {
+        translate([20, 60, 10]) rotate([90, 0, 180]) {
+            extrusion_inner_corner_bracket(E20_inner_corner_bracket);
 
-    translate([60, 60]) {
-        extrusion_corner_bracket_assembly(E20_corner_bracket);
-        translate([-eWidth / 2, 0, 0])
-            rotate([-90, 0, 0])
-                extrusion(E2020, 30);
-        translate([-eWidth, -eWidth / 2, 0])
-            rotate([0, 90, 0])
-                extrusion(E2020, 50);
+            translate([-eWidth / 2, 0, 0])
+                rotate([-90, 0, 0])
+                    extrusion(E2020, 20, false);
+
+            translate([-eWidth, -eWidth / 2, 0])
+                rotate([0, 90, 0])
+                    extrusion(E2020, 40, false);
+        }
+
+        translate([100, 60, 10]) rotate([90, 0, 180]) {
+            extrusion_corner_bracket_assembly(E20_corner_bracket);
+
+            translate([-eWidth / 2, 0, 0])
+                rotate([-90, 0, 0])
+                    extrusion(E2020, 30, false);
+
+            translate([-eWidth, -eWidth / 2, 0])
+                rotate([0, 90, 0])
+                    extrusion(E2020, 50, false);
+        }
     }
 }
 
 if($preview)
-    let($show_threads = true)
-        extrusion_brackets();
+    extrusion_brackets(true);
diff --git a/tests/png/extrusion_brackets.png b/tests/png/extrusion_brackets.png
index aa612ae..0246350 100644
Binary files a/tests/png/extrusion_brackets.png and b/tests/png/extrusion_brackets.png differ
diff --git a/tests/png/pcbs.png b/tests/png/pcbs.png
index 654e20f..d933cd0 100644
Binary files a/tests/png/pcbs.png and b/tests/png/pcbs.png differ
diff --git a/tests/png/scs_bearing_blocks.png b/tests/png/scs_bearing_blocks.png
index ee5342d..97e8c38 100644
Binary files a/tests/png/scs_bearing_blocks.png and b/tests/png/scs_bearing_blocks.png differ
diff --git a/tests/scs_bearing_blocks.scad b/tests/scs_bearing_blocks.scad
index deb4864..2c798db 100644
--- a/tests/scs_bearing_blocks.scad
+++ b/tests/scs_bearing_blocks.scad
@@ -22,7 +22,7 @@ use <../utils/layout.scad>
 include <../vitamins/scs_bearing_blocks.scad>
 
 module scs_bearing_blocks()
-    layout([for(s = scs_bearing_blocks) 2 * scs_size(s)[0]]) {
+    layout([for(s = scs_bearing_blocks) scs_size(s).x], 10) {
         part_thickness = 5;
         scs_bearing_block_assembly(scs_bearing_blocks[$i], part_thickness);
 
diff --git a/tests/sk_brackets.scad b/tests/sk_brackets.scad
index aa19505..0ca77cb 100644
--- a/tests/sk_brackets.scad
+++ b/tests/sk_brackets.scad
@@ -31,10 +31,9 @@ module sk_brackets() {
         sk_bracket_assembly(sk_brackets[$i], screw_type = screws[$i], nut_type = nuts[$i], max_screw_depth = depths[$i]);
         translate([0, -sk_hole_offset(sk_brackets[$i]) - extrusion_width($i < 2 ? E2020 : E3030) / 2, 0])
             rotate([0, 90, 0])
-                extrusion($i < 2 ? E2020 : E3030, 20);
+                extrusion($i < 2 ? E2020 : E3030, 20, false);
     }
 }
 
 if($preview)
-    let($show_threads = true)
-        sk_brackets();
+    sk_brackets();
diff --git a/vitamins/extrusion.scad b/vitamins/extrusion.scad
index 4ecb965..913e82b 100644
--- a/vitamins/extrusion.scad
+++ b/vitamins/extrusion.scad
@@ -117,12 +117,11 @@ module extrusion_cross_section(type, cornerHole) {
                 extrusion_center_section(type);
 }
 
-module extrusion(type, length, center = false, cornerHole = false) { //! Draw the specified extrusion
+module extrusion(type, length, center = true, cornerHole = false) { //! Draw the specified extrusion
 
-    vitamin(str("extrusion(", type[0], ", ", length, ", ", center, "): Extrusion ", type[0], " x ", length, "mm"));
+    vitamin(str("extrusion(", type[0], ", ", length, arg(cornerHole, false, "cornerHole"), "): Extrusion ", type[0], " x ", length, "mm"));
 
     color(grey90)
         linear_extrude(length, center = center)
             extrusion_cross_section(type, cornerHole);
 }
-
diff --git a/vitamins/pcbs.scad b/vitamins/pcbs.scad
index 47b58bd..cd07f07 100644
--- a/vitamins/pcbs.scad
+++ b/vitamins/pcbs.scad
@@ -352,6 +352,6 @@ RAMPSEndstop = ["RAMPSEndstop", "RAMPS Endstop Switch",
     []];
 
 
-pcbs = [ExtruderPCB, PI_IO, RPI0, EnviroPlus, RPI3, ArduinoUno3, ArduinoLeonardo, Keyes5p1, PERF80x20, PERF70x50, PERF70x30, PERF60x40, PERF74x51, PSU12V1A, DuetE, Duex2, Duex5, Melzi, ZC_A0591, RAMPSEndstop];
+pcbs = [RAMPSEndstop, ExtruderPCB, PI_IO, RPI0, EnviroPlus, RPI3, ArduinoUno3, ArduinoLeonardo, Keyes5p1, PERF80x20, PERF70x50, PERF70x30, PERF60x40, PERF74x51, PSU12V1A, DuetE, Duex2, Duex5, Melzi, ZC_A0591];
 
 use <pcb.scad>
diff --git a/vitamins/scs_bearing_block.scad b/vitamins/scs_bearing_block.scad
index 6a8d4b2..90d997c 100644
--- a/vitamins/scs_bearing_block.scad
+++ b/vitamins/scs_bearing_block.scad
@@ -18,7 +18,7 @@
 //
 
 //
-// SCSnUU and SCSnLUU bearing blocks
+//! SCSnUU and SCSnLUU bearing blocks
 //