Revision as of 22:47, 18 April 2024

Resources

Reynolds, Silicone and More, Retail:
- Reynolds is national, with a retail store in Tempe, just North of the 202, off McClintock
- https://www.reynoldsam.com/location/phoenix/

High Temperature 3D Printer Resin (for directly printing molds)
- 250C, $2.15/oz: https://www.amazon.com/dp/B08V8T9NZL
- 180C, $1.15/oz: https://www.amazon.com/dp/B08GJTGPYQ
Eutectic Bismuth Tin
- 58% Bi 42% Sn by weight
- 138C melting point (280F)
- 150C / 300F casting
- Tin (Sn) 232C / 450F
- Bismuth (Bi) 272C / 521F
- Bi-Sn tensile strength: 55 MPa, Mild Steel (the cheap stuff): 400-550 MPa, 6061 Aluminum (the cheap stuff): 290 MPa, Tin 220, 3003 aluminum: 186, HDPE plastic 20 - 30, epoxy resin 26 - 85
- Bi-Sn Density: ~8,500 kg/cm3, Mild Steel: 7,850 kg/cm3
- A little denser than steel and a lot weaker than most metal.
- Roughly as strong as epoxy resin (which can be cast in the same molds and is less dense).
Heat Stable Silicone Mold Release
- https://www.amazon.com/dp/B0018NBE8A
Cheaper Tin and Bismuth (free shipping over $150):
- https://www.rotometals.com/tin-cut-wire-pieces-99-9-pure-1-pound-made-in-usa/

Mars 1 Bed Size: 68mm x 120mm

Create a clip art style image in Inkscape.
- I use layers as my checkpoint stack, so I can recover to a previous checkpoint if needed.
- Draw outlines only.
- Use Bezier curves and straight lines.
- Minimize the number of control handles to get fair curves.
- File > Document Properties > Page > Custom Size: printer bed size or smaller (portrait or landscape).
- Set the line width to 0.5mm.
- Set line ends to rounded.
- Keep inset regions at least 2mm wide.
- Clean up everything as much as possible.
  - Check where endpoints meet other curves. Close gaps, pull in dangling ends.
- Path > Stroke to Path
- Select 1 path, then all the rest, then Path -> Union
- Save as SVG
Import Into Blender
Set Scene > Units > Length to Millimeters
Scale the image to smaller than printer bed size (portrait or landscape).
Convert to Mesh
Edit Mode > Vertices > Select All > x > Limited Dissolve > 1 degree
Clean Up Excessive Vertices
- Loop Select, Remove Critical Vertices, Dissolve by Distance 0.1m or 0.2m
- Pay Special Attention to Inside Corner Vertices
- Merge vertices at center or dissolve vertices as needed.
Loop Select and Create Face
Inset by 0.5mm
Clean Up Corners
Select Inset Face
Select More
Unselect Inset Face
Triangulate Faces
Select Inset Face
g > z > 0.7 > - (move face 0.7mm in the negative z direction)

@@ Line 82: / Line 82: @@
 #* Save as SVG
 # Import Into Blender
-# Set Scene > Units > Length to Centimeters or Millimeters
+# Set Scene > Units > Length to Millimeters
 # Scale the image to smaller than printer bed size (portrait or landscape).
 # Convert to Mesh
 # Edit Mode > Vertices > Select All > x > Limited Dissolve > 1 degree
+# Clean Up Excessive Vertices
+#* Loop Select, Remove Critical Vertices, Dissolve by Distance 0.1m or 0.2m
+#* Pay Special Attention to Inside Corner Vertices
+#* Merge vertices at center or dissolve vertices as needed.
+# Loop Select and Create Face
+# Inset by 0.5mm
+# Clean Up Corners
+# Select Inset Face
+# Select More
+# Unselect Inset Face
+# Triangulate Faces
+# Select Inset Face
+# g > z > 0.7 > - (move face 0.7mm in the negative z direction)