Calculate the rotating load correctly
Rated kilograms do not describe how an offset frame behaves. Include fixture mass, load distribution, center of gravity, inertia, acceleration and any support points across the full rotation.
- Workpiece plus fixture mass
- Center offset and inertia
- Load distribution and support
Choose the motion architecture
A simple rotary table, headstock-tailstock unit, tilt-rotate positioner or multi-station indexer solves different access and loading problems. Select the fewest axes that keep critical welds accessible and productive.
- Required welding orientations
- Part length and fixture span
- Operator loading during robot work
Coordinate reach, controls and safety
Model the robot and positioner together. Check swept volume, cable routing, synchronization, controller capacity, home positions, guarding and safe loading zones rather than adding the positioner after robot selection.
- Coordinated external axis
- Robot reach and collision envelope
- Guarding and load-zone separation
Compare lifetime production needs
Consider changeover, bearing and drive maintenance, fixture repeatability, service access and future part families. The lowest purchase price can be expensive if loading, setup or repair stops the welding cell.
- Changeover and repeatability
- Maintenance and spare parts
- Future fixture and part range
Decision checklist
Use the same inputs when comparing supplier proposals.
| Decision area | Inputs to confirm |
|---|---|
| Calculate the rotating load correctly | Workpiece plus fixture mass; Center offset and inertia; Load distribution and support |
| Choose the motion architecture | Required welding orientations; Part length and fixture span; Operator loading during robot work |
| Coordinate reach, controls and safety | Coordinated external axis; Robot reach and collision envelope; Guarding and load-zone separation |
| Compare lifetime production needs | Changeover and repeatability; Maintenance and spare parts; Future fixture and part range |
Move from research to a commercial review
Send the workpiece, fixture and desired orientations for a positioner shortlist.