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Reflow Calculator

The Reflow Calculator evaluates the radial stackup and manufacturing feasibility of a catheter design. It calculates the pre-reflow dimensions of each layer needed to hit the target post-reflow geometry, accounting for layer clearances and tolerances during the build process.

It is the Reflow tab, reachable from the tab bar or from Tools → Reflow Calculator. It requires a built model; until there is one the tab shows a short "build the model first" state with a button that takes you to Catheter Setup. Its results can be included in a report; see Reports.

The tab is laid out like the rest of the workspace: a left rail holding the section you are working on, the finished size it comes out at, and the two actions; the cross-section view in the middle; and the design grid on the right.

Custom sizes are held per section, so you can work through several sections and export once. Switching between millimetres and inches restates everything in place: nothing is recalculated, and no sizing you have pinned is lost.

Reflow Visualizer​

The visualizer provides a dynamic, scaled cross-sectional representation of the catheter's layer stackup. The Assembly / Reflow toggle sits in its title row.

  • Assembly: Displays the catheter layers in their pre-reflow state, illustrating the necessary manufacturing clearances and gaps between layers prior to lamination.
  • Reflow: Displays the catheter in its final consolidated state, as it would appear after the reflow process.

Design Grid​

The Design Grid allows for detailed inspection and modification of each layer's pre-reflow dimensions.

  • Layer Properties: Displays the Name, Type, and Material of each layer as defined in the Catheter Setup tab.
  • Dimensional Controls (ID, Wall, OD):
    • Linked (Auto) Mode: By default, layers are "linked" (the chainlink icon). The software calculates the ideal nominal dimensions to maintain the required manufacturing clearances and final reflowed dimensions.
    • Unlinked (Custom) Mode: Clicking the link icon disables that calculation so you can enter your own ID, Wall, or OD, typically to round to the nearest extrusion size available for that layer. The change cascades outward, updating the layers outside the edited one so the spacing and the overall geometry stay valid.
  • Tolerance (Tol): Enter the expected manufacturing tolerance for each layer to evaluate its impact on the worst-case cumulative tolerance.
Layer editing constraints

To keep designs physically realistic, some layers are constrained when customized:

  • Braid, Coil, and Pullwire layers: custom Inner Diameters (IDs) can be set, but wall thickness is fixed by the defined wire/lumen dimensions.
  • Mandrel: modeled as a solid core, so the ID is locked.
  • Multi-Lumen Core: on multi-lumen core designs, the innermost row is the extruded core itself. It is the reflow boundary (walls build outward from its OD), it never reflows, and its dimensions are locked to the Core Profile definition. It is drawn statically in the visualizer.
  • Polymer, Liner, Multi-Lumen Extrusion, and Heat Shrink layers: both ID and wall thickness are fully customizable.

Finished Size​

The Finished Size card in the left rail is what the stack-up in the grid actually makes.

  • The headline is the post-reflow outer diameter of the finished catheter at the layer sizes now in the grid. The outermost heat shrink is excluded (it is removed after reflow), and the line beneath it carries the worst-case cumulative tolerance stack (±), the simple sum of the per-layer tolerances.
  • Nominal design OD: The same diameter with every layer left in Linked (Auto) mode: the finished OD the design asks for, before any tubing sizes are pinned.
  • Change vs nominal: How far the customized stack-up has moved the finished OD from the design's own answer. It reads on the nominal size until you unlink something.
  • Min shrink ratio: The lowest heat-shrink recovery ratio that will still compress this stack-up, including a 15% margin to maintain compression force. Past 2:1 the value turns red: that exceeds standard off-the-shelf recovery, and a specialized heat shrink would be needed.

Actions​

  • Export to Setup Wizard: Pushes the current custom layer dimensions back into the Catheter Setup tab, permanently overriding the original design intent for every section you have modified. Requires confirmation and cannot be reversed.
  • Revert to Nominal: Resets all unlinked layers back to their default auto-calculated nominal dimensions.

Exporting​

This tool has no export buttons of its own. Tick its block in Report → Generate Report... to carry the stack-up into a report. Choosing Excel also writes the layer dimensions, tolerances, and gaps as their own sheet, for procurement or engineering review. See Reports.