Weld positioners, such as the rotating welding positioner, are known to assist welders in welding large assemblies. What many might not know is that it is possible to mechanically position small assemble to provide the same function positioning equipment can offer. Regardless of the size of a weldment, when positioned properly, it can improve safety, save production floor space, reduce fatigue of welders, and also improves the weld quality.
3 Things Welders Should Keep in Mind
When selecting, maintaining, or operating a weld positioner, the following points should be kept in mind by welders, regardless of the size of the weldment.
1. Never Forget the Center of Gravity (COG)
In choosing the right positioning device for a welding job, a welder should consider not just the size or weight of the weldment, but also the center of gravity (COG) and its distance from the positioning device. The center of gravity is the point where the weldment equally balances on all the axes. As more parts and materials are added to the positioner, the center of gravity of the weldment changes. These changes in COG should be considered before selecting a positioning device.
An electric motor helps rotate the table and this motor can be controlled by either the hand or the feet. The motor and control of the positioner must be selected based on the required size and speed for the welding operation. The specifications provided by the positioner’s manufacturer can guide you in selecting the right motor and control. Additionally, welders should check the horizontal and vertical loading specifications to make sure that the positioner can handle the weight of the weldment. Your positioner should be able to support the highest possible load.
2. Attach Weldment Correctly
The way a weldment is attached to a positioning device is just as important as the positioner itself since separation occurs naturally at this point. Production fixtures are usually designed to be repeatedly used for a specific application. These fixtures are permanently mounted to the positioner and their shape helps with easy part alignment.
When sizing the positioning device, welders should consider the weight and distance added by the chucks and fixtures. Although the weight of the weldment directly applies torque to the device, the torque significantly increases when the distance of the weight is increased. For example, a 50-pound weldment with a distance of 3 inches creates a torque of 12.5 ft.-lbs. If the distance of the weldment from the face of the positioning table is increased to 6 inches, the torque will also increase to 25 ft.-lbs.
3. Use Turning Rolls for your Cylinders
A cylindrical weldment can be rolled. Small turning rolls (idler or powered rolls) can be used to rotate a vessel to ensure down hand welds. The powered rolls can be used to provide an even circumferential weld since they provide steady rotation. Idler rolls, on the other hand, can be used to support longer vessels and pipes. They are usually used to add flanges to the ends of pipes, or to connect pipes to vessels.