update to lock-based joint

mechanism/BOM.md

@@ -39,12 +39,6 @@ foot_bottom | ![foot_bottom](files/foot_bottom.jpg) | 1 (x6) |
 foot_ground | ![foot_ground](files/foot_ground.jpg) | 1 (x6) |
 foot_tip | ![foot_tip](files/foot_tip.jpg) | 1 (x6) |
 
-### Tools
-
-Filename | Thumbnail | Required |
--------- | --------- | -------- |
-tools_mount | ![tools_mount](files/tools_mount.jpg) | 1 
-
 ## Others
 
 Name | Spec | Thumbnail | Required | Note
@@ -53,5 +47,4 @@ Screw | M2 6mm | ![6mm](files/M2_6mm.JPG) | 54 | Servo Arm: 1 x 18<br>Joint: 4 x
 Screw | M2 12 or 10mm | ![10mm](files/M2_10mm.JPG) | 6 | Thigh: 1 x 6<br>12mm is better<br>(10 is also ok if 12 is hard to find)
 Screw | M2 30mm | ![30mm](files/M2_30mm.JPG) | 36 | Servo: 2 x 18
 Nuts | M2 | ![6mm](files/M2_nut.JPG) | 36 | Servo: 2 x 18
-Bearing | 8x4x3 mm | ![bearing](files/bearing.JPG) | 18 | Servo: 1 x 18
-Cooper/Aluminum Tube | 6 (height) x 4 (dia.) | ![tube](files/tube_6x4mm.JPG) | 18 | Servo: 1 x 18
+Pin (304) | M4 6mm | ![pin](files/pin_M4_6mm.JPG) | 18 | Servo: 1 x 18