add png

README.md

@@ -4,7 +4,7 @@ Parametric, low-complexity fabrication linear axis designs using ubiquitous hard
 
 ## Gantry for NEMA23 Motor, 0.25" Aluminum
 
-![RCTN23-025ALU](images/RCTN23-025ALU.png)
+![RCTN23-025ALU](images/RCTN23-dwg.png)
 
 [RCTN23-025ALU Fusion CAD File](cad/RCTN23-025ALU_v49.f3d)
 
@@ -26,9 +26,10 @@ Type | Size | QTY | Where Used | McMaster PN
 --- | --- | --- | --- | --- 
 SHCS | M3x12 | 8 | Connecting Lap and Tab Aluminum, and Belt Blocks |  
 FHCS | M3x12 | 8 | Nice option for flush-mounting things | 
-SHCS | M3x40 | 2 | Used *only* when pre-loading bearing rollers | 
-SHCS | M3x30 | 2 | Used *only* when pre-loading bearing rollers | 
-Belleville Washer | 3.1mm ID | 12 | Used *only* when pre-loading bearing rollers |
+SHCS | M3x35 | 2 | Used *only* when pre-loading bearing rollers | 91292A033
+SHCS | M3x45 | 2 | Used *only* when pre-loading bearing rollers | 91292A025
+Belleville Washer | 3.1mm ID | 12 | Used *only* when pre-loading bearing rollers | 96445K157
+Locknut | M3, Nylon | 2 | Used *only* when pre-loading bearing rollers | 90576A102
 SHCS | M5x10 | 1 | Connecting Nema 23 Motor |  
 SHCS | M5x16 | 3 | Nema 23 Motor through arcs | 
 Shoulder Screw | 8mm Shoulder x 8mm x M6 | 10 | Guide Roller Shaft | 92981A198
@@ -63,6 +64,26 @@ Countersink Bit | Flush Mounting |
 
 ![](video/SEQ-rct-add-blk-enc.mp4)
 
+## Gantry for NEMA23 Motor, 0.375" HDPE
+
+![RCTN23-025ALU](images/RCTN23-dwg.png)
+
+[RCTN23-025ALU Fusion CAD File](cad/RCTN23-0375HDPE_v2.f3d)
+
+Type | Size | QTY | Where Used | McMaster PN
+--- | --- | --- | --- | --- 
+Button Head Thread-Forming | No. 6, 3/4" | 8 | Connecting Lap and Tab HDPE, and Belt Blocks | 99512A265
+Flat Head Thread-Forming | No. 6, 3/4" | 8 | Flush Mounting HDPE | 95893A258
+SHCS | M3x40 | 2 | Used *only* when pre-loading bearing rollers | 91292A024
+SHCS | M3x30 | 2 | Used *only* when pre-loading bearing rollers | 91292A022
+Belleville Washer | 3.1mm ID | 12 | Used *only* when pre-loading bearing rollers | 96445K157
+Locknut | M3, Nylon | 2 | Used *only* when pre-loading bearing rollers | 90576A102
+SHCS | M5x10 | 1 | Connecting Nema 23 Motor |  
+SHCS | M5x16 | 3 | Nema 23 Motor through arcs | 
+Shoulder Screw | 8mm Shoulder x 8mm x M6 | 10 | Guide Roller Shaft | 92981A198
+Shoulder Screw | 8mm Shoulder x 16mm x M6 | 2 | Belt Guide Roller Shaft | 92981A202
+Bearing Shim | 8mm ID x 10mm OD x 1mm Thick | 38 | Roller Separation | 98089A381 
+
 # REF
 
 Find [Open Assemblies Hardware Reference](https://github.com/jakeread/openassemblies/blob/master/hardware.md) for shorthands etc. 
@@ -72,6 +93,7 @@ Find [Open Assemblies Hardware Reference](https://github.com/jakeread/openassemb
  - doc
   - bom
   - hardware callout drawing (probably more useful than video)
+  - preloading drawing 
 
  - nice to include a note on what those flexures are up to ... and some other design decisions 
  - kinematic mounts are three button head cap screws on 20mm grid w/ reciprocal / wherever-u-like mount ins