Trimming reduces a part by cutting strips of material off its edges. Its main purpose is processing after CNC.
Why trimming is needed
A CNC machine cannot reliably clamp and process a part that is too small. To work around this, the part is made with allowance — larger than required, all CNC operations (drilling, grooves, milling) are performed on it, and then it is trimmed to the final size. Trimming sets exactly how much material to remove from each side after processing to get the part of the needed size. Therefore trimming is always the finishing operation, performed after CNC.
How offsets are set
The form has four fields — by the sides of the part:
- Offset from the top edge;
- Offset from the bottom edge;
- Offset from the right edge;
- Offset from the left edge.
Each value is the width of the strip (in mm) cut off the corresponding side. You can fill in one side or several at once.
Offset limits
The minimum offset is set by a production setting (by default 20 mm) — you cannot set a trim smaller than this value. The maximum is limited by the part's own size: the vertical offset (top/bottom) cannot exceed the part's height, the horizontal one (right/left) — its width. Values can be entered with hundredth precision.
Formulas
The offsets support formula input, like other dimensional operations — this is handy when the trim amount depends on the part's dimensions or the order's parameters.
Adding and saving
The button at the bottom of the form is «Add» for a new trim or «Save» when editing a previously set one.