The backgauge provides a repeatable reference for positioning a component before a bend. Choosing it well means checking the reference available at every stage of forming, not simply ordering the largest advertised axis count.
Begin with the gauging reference
Mark the intended reference edge on each bend in your drawing. After the first bend, that edge may no longer sit flat or be accessible to a conventional finger. A return flange, notch or formed feature can change how the part must be presented.
Consider small components as carefully as large panels. A part may have enough bending length available but offer little stable contact for gauging. The finger shape, support surface and operator’s ability to present the part consistently all affect the result.
Separate depth, height and lateral travel
X controls depth, R controls height and Z describes lateral positioning along the machine. Independent movements can provide different finger positions where the design supports them. Confirm the naming and movement diagram for the quoted backgauge. Y1 and Y2 are ram axes, not backgauge movements.
Travel figures also need context. Check the usable range with the proposed tooling, the minimum gauge distance, retraction through the bend sequence and any restrictions imposed by the frame or component. Do not assume a historic travel specification applies to every current PBXS model.
Assess fingers and support
Check finger contact faces, adjustability and suitability for the component edge. Ask how narrow, interrupted or angled edges will be gauged. Long or heavy components may need additional support, but a backgauge should not be treated as lifting equipment unless specifically designed and rated for that duty.
Finished flange dimensions depend on more than the commanded X position. Blank dimensions, tooling, material behaviour and the actual contact with the fingers can all influence the finished component. Evaluate measured parts rather than control resolution alone.
Run a practical comparison
Choose a simple bracket, a component with different flange heights and your most awkward return. Demonstrate the complete sequence, including loading, turning and removal. Record which adjustments require the operator to stop and change the setup. Repeat the job after a changeover to test recall.
Selecting a PBXS backgauge
Selmach’s premium Morgan Rushworth PBXS range should be assessed as a complete machine, controller, backgauge and tooling package. The standard configuration has CNC-controlled X and R backgauge movements alongside the Y1 and Y2 ram axes, with manual lateral positioning of the fingers. Optional configurations include independent X1/X2 or R1/R2 movements and CNC-controlled Z or Z1/Z2 lateral positioning. Request a named movement list and a diagram for the proposed configuration, with manual adjustments clearly distinguished from CNC control.
Send folded drawings or STEP models, material details and required tolerances. Discuss gauging and component access with Selmach before ordering extra movements. Our axes guide explains the terminology; the PBXS range page is the starting point for a model-specific assessment.
Published 21st October 2026