8 Ton Welding Positioner for Boom Manufacturing in Delhi

Case Study: 5

A leading crane and heavy equipment manufacturer in Delhi NCR was looking to improve the fabrication process for a 12 metre telescopic mobile crane boom. The fabricated high-strength steel boom weighed approximately 6 tonnes, but its length created a more complex handling problem than its weight suggested. Cyclotron supplied an 8 Ton Headstock-Tailstock Welding Positioner to support and rotate the boom while maintaining its alignment during welding.

The Challenge

A crane boom is a long, slender fabricated box section. The weight is manageable but not the geometry.

At approximately 12 metres long, the boom’s centre of gravity creates a significant bending moment on the positioning system. Selecting a machine based only on the 6 tonne job weight would not account for the effect of the load’s distance from the rotation axis.

Deflection was another concern. Any droop or movement in the support system during welding can introduce straightness and dimensional errors into a structural component designed to carry loads over its service life.

The boom also had four long longitudinal seams, each approximately 10 to 12 metres. Before the positioner, the typical process involved welding one side, using a crane to flip the boom, re-levelling it, and continuing with the next seam. The assumed process required approximately three crane flips per boom, with around 40 minutes per flip.

Cyclotron Welding Positioners from India

Cyclotron manufactures industrial welding positioners from 100 kg to 100 Tons capacity, designed for robotic/manual welding, heavy fabrication, and high-production welding environments.
Cyclotron manufactures all types of Manual/Robotic welding positioners like 1 axis, 2 axis, 3 axis, Headstock-tailstock, L Type, skyhook, etc

Our Approach

Cyclotron supplied an 8 Ton Headstock-Tailstock Welding Positioner with a custom boom holding fixture. The driven headstock and supported tailstock allowed the 12 metre boom to be supported along its length rather than being cantilevered from a single faceplate.

The positioner indexes the boom through controlled 90 degree rotations, presenting each longitudinal seam in the flat or downhand welding position. This allows the welder to work on long seams without repeatedly changing the orientation of the complete assembly.

For this application, machine sizing was based on the loading condition rather than simply the nameplate capacity. The design parameters considered a 6 tonne boom, approximately 650 mm CoG height, and up to 500 mm eccentricity.

The headstock-tailstock arrangement also reduces the unsupported span of the boom. This is important for a long fabricated section where fixture movement or excessive deflection can affect straightness.

Controlled rotation helps maintain a consistent welding position along the length of the seam. Depending on the welding process and applicable WPS, a 10 to 12 metre longitudinal seam can then be completed as a continuous downhand weld rather than being interrupted by repeated handling.

The objective was not simply to rotate the boom. It was to hold the component in a controlled position while welding.

Integration

An 8 Ton positioner does not automatically mean that every 8 tonne workpiece can be rotated safely. Usable capacity depends on the relationship between workpiece weight, centre of gravity, eccentricity, support span, and bending moment.
For this application, the design considered a 12 metre boom, approximately 6 tonnes, 650 mm CoG height, and 500 mm maximum eccentricity, with headstock-tailstock support.
The important calculation is therefore:
Weight + Eccentricity + CoG + Length + Support Span + Bending Moment
not weight alone.

The Result

These figures are a projection based on typical handling and arc-on-time improvements, not a measurement of this installation.

Parameter	Before	With Positioner
Crane flips per boom	3	0
Time per crane flip	≈40 min	0
Handling time	≈2 hrs	Minimal
Longitudinal seams	4 × 10 to 12 m	Same
Welding position	Mixed	Predominantly downhand
Projected arc-time improvement		20 to 30%

At an assumed production volume of 15 booms per month, eliminating approximately two hours of handling per boom at a loaded labour and crane cost of ₹2,500 per hour represents around ₹75,000 per month in handling-related savings.

When potential reductions in grinding, welding time, crane usage, and straightening or rework are included, the projected overall saving is approximately ₹1.0 to ₹1.5 lakh per month.

At an assumed positioner investment of ₹22 lakh, a conservative projected payback period is approximately 15 to 24 months, depending on actual production volume and operating costs.

For structural boom manufacturing, the value is not limited to handling time. One avoided straightness-related reject or major rework operation can have a greater impact than several days of handling savings.

Welding Long, Overhung Structures?

Working with crane booms, long chassis, or other overhung weldments? Share your component drawing, job weight, overall length, and centre-of-gravity details with Cyclotron. Our engineering team can evaluate the loading conditions and recommend a suitable welding positioner for the application.