Viewer and tree

The Viewer & tree page is where you load your models and grow the sprue tree. The sidebar on the left holds the settings, from top to bottom, and the 3D view shows the tree inside its flask.

#Loading models

Click Open model… to load a part, or + Add part to add another one to the same tree. The app reads:

• STL, both binary and text (ASCII).
• OBJ.
• 3MF, which keeps its real units.

Each part in the Parts list has its own quantity, so you can cast different pieces in one pour: say six rings and four pendants.

#Metal and flask

• Metal & price picks the alloy, grouped by type. Prices come live from the spot market, and you can type your own price to override it. A link takes you to where to buy casting grain.
• Flask & casting sets the flask size, the flask type (perforated or solid) and the casting method (centrifugal, vacuum, or tilt and induction).
• Pattern says whether the pieces are wax or printed resin. Resin pieces are spaced further apart (5 mm rather than 3 mm) because resin expands as it burns out.
• Sprue base models the rubber base you'll stand the tree in, with its dome, hole and how deep the trunk sits.

#Generating the tree

Click Generate sprue tree. Auto-sprue then:

• finds where each piece should attach (at its heaviest section),
• sizes the feed sprues, trunk and button for your metal and casting method,
• sets the branch angle and turns each piece to fill well,
• lays the pieces out inside the flask with safe clearances.

Clear removes the tree and leaves your parts loaded.

#Reading the flask

The flask is drawn as a see-through ghost, modelled on real flasks with their flange and cross supports.

• The yellow line is the recommended 8 mm safe distance from the flask wall.
• The red line is the 6 mm hard minimum.

You can show or hide the flask and each zone with the switches at the top right of the view. A legend explains the colours.

The app also warns when a piece is too close to the wall or touches another piece.

#Tree results

The Tree results panel shows the pieces placed, the metal for the parts and the sprues, the cost per piece and per pour, the sprue sizes and the layout.

#Moving pieces by hand

Click a piece in the 3D view to select it. Then press W to move it or E to rotate it, with optional snapping. Its feed re-routes to where the piece now sits.

• Reset piece puts one piece back. Reset all pieces puts them all back.
• Apply to all copies one piece's adjustment to every copy of that part.
• Your edits survive re-spruing.

For full freedom over the layout, including scaling, see Custom sprue tree.

#Weigh the wax tree

Weighing the finished tree is the usual bench check of how much metal to melt. Under Weigh the wax tree:

1. Weigh the tree on its rubber base and type it into Tree on base (g).
2. Weigh the empty base and type it into Empty base (g).
3. Check the pattern density. Casting wax is about 1.00, which is the usual rule of thumb.

The app works out the pattern weight and the metal to melt for your alloy, including the button, and compares it with the estimate from the 3D model.

Reused metal in the melt (g) tracks how much of the melt is buttons and sprues from earlier casts. Makers commonly say to use no more than half reused metal.

#Thin walls

Tick Show wall thickness at the top right of the view to colour the model by how thick each spot is. Spots too thin to fill are flagged, and the app checks the feed attaches at the thickest section.

#Shrinkage and ring size

Metal shrinks a little as it cools, so a casting comes out slightly smaller than its pattern. Shrinkage & ring size scales the exported model up to make up for it, usually 1.5–2% for the metal you picked.

For rings, choose the ring size you want after casting and the app shows the size to print or carve.

#Display

Under Display you can turn on smooth shading or wireframe, change the wax colour, and frame the model (F).