GC-CAD
Tutorials/Nesting
Tool Path·Nesting

Leads, cut order and chain cutting

GCnester · GCmaker · 7 steps · Published September 2026

Placed parts aren't a program yet. This guide walks through everything between a finished nest and G-code: cut settings, leads, small holes, tool paths, the cut order, chain cutting and the skeleton.

01
Check the cut settings

In the Plasma Settings pane, confirm the consumable, cut quality and path offset. Cut Speed and Cut Height each have a Machine tick: ticked, the value comes from the machine's chart for that consumable and thickness. Those charts are yours to maintain; the program is only as good as the numbers in them.

02
Set the leads for the job

In the Leads pane, Defaults opens the editor for this nest's standard leads. For the nest defaults, Lead-In can be Line or Arc and Lead-Out can be Line, Arc or None; Over Cut is a distance. Which fields apply depends on the type you pick. Changes apply when you accept the editor.

03
Move or override one lead

Select a contour on the plate and right-click it to override its lead settings; an override can also switch that contour's lead-in to None. Use Set Lead Position or Move Lead In to click the point on the contour where the lead should land. Reset clears the selected contour's lead overrides, including its position, and restores the nest defaults. Leads sit on the scrap side of the cut; after tool paths are created, each one is checked and flagged if it looks like it would collide.

04
Handle small holes

In Small Holes, choose Auto or Absolute under Threshold, set Hole Size when using an absolute threshold, and choose the entry treatment under Below It (Center Pierce pierces at the hole's centre and runs straight to the contour). Flag holes too small to cut checks Min Size and blocks generation of an undersized inside cut until you set that hole to Ignore or Drill. Nothing is converted or deleted for you.

05
Create the tool paths

Click Create Tool Paths. The plate redraws with pierces, lead-ins, kerf-offset contours, lead-outs and rapids, the estimates pane fills in, and any lead that looks like it would hit a neighbouring part, an avoid zone or a remnant cutout shows a red marker with a note above the list. Fix Leads tries alternative anchor positions and rebuilds the program; review the result, and move any lead it could not clear by hand. Delete Tool Paths clears them, for example before rearranging parts; reordering after they exist rebuilds the program in the new order.

06
Choose the cut order

Cut-order strategies come with Pro, Business and the demo; Standard keeps the default order and Manual Reorder. Strategy sets the automatic order: Nearest Neighbor picks nearby uncut work next; Nearest, Skip Neighbors avoids cutting immediately beside the last part; Heat Spread keeps consecutive cuts apart to reduce heat concentration in one area; Serpentine Rows and Serpentine Columns work back and forth; Smallest First cuts small parts before large ones. Auto Reorder reapplies the strategy, Manual Reorder lets you drag rows, and Suppressed skips one placed copy without removing it. No strategy can promise a flat plate or the shortest route.

07
Chain cutting, rapids and the skeleton

Chain Cutting links eligible consecutive outer cuts through scrap so a chain takes one pierce; a link never enters a part and is never longer than Max Link. With Bridge (parts stay attached) on, each eligible chained outer stops a Bridge Width short of closing and has no lead-out, so the parts lift out together; profiles the bridge logic can't recognise are left unbridged. Route rapids around cut parts detours torch-off moves around outlines already cut free; it's 2D routing, not a sensor. Auto Skeleton draws cuts across the leftover so it lifts off in pieces, Edit Skeleton lets you draw your own on the grid (Major Grid and Minor Grid set the snap spacing), and Skeleton Leads sets the lead used when a skeleton line starts. Skeleton cuts are composed after every part cut; check them in playback like everything else.

Questions people ask

Heat Spread and Nearest, Skip Neighbors both keep consecutive cuts apart, which reduces heat building up in one area. Neither can promise the plate stays flat: material, thickness, clamping and your machine decide that. Try it on a test sheet.

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