Guide To Weld Positioners
About Welding Positioners
Weld positioners can be mounted in any configuration. This enables large weldments, fabrications or assemblies to be rotated in a controlled way in order to present the optimum angle to a welder or operator for welding or other operation such as assembly.
Weld Positioners are used by welders, welding shops and production facilities to position and move weldments in order to:
- increase welding productivity and weld deposition rates
- increase welding quality and reduce errors and rejects
- reduce part movement through the shop
- enable welding specifications to be repeatably met
- reduce welder fatigue
- reduce welding production floor space
- enable robotics to perform welds
- increase safety
- enable large parts to be welded without the welder having to move to access joints
- enable welders of to produce welds through elimination of overhead or vertical welds
Welding Positioner Automation
Manual Weld Positioners
Semi-automatic Weld Positioners
Automatic Weld Positioners
Applications and Options for Weld Positioners
Weld positioners are used in a variety of manufacturing operations, but they are most often used to rotate parts for welding and assembly. Weld positioners are used across industries such as aerospace, automotive manufacturing, construction and trains, steel and pipe fabrication, construction, pressure vessel fabrication, machinery manufacturing, and more.
Types of Rotary Welding Positioners
There are a multitude of different types of rotary welding positioners. They come in all shapes and sizes depending on the application they are to be used in. Here are a couple of popular options.
Rotary Indexer Weld Positioners
The most basic type of rotary welding positioner is a rotary indexer. Rotary indexers are standard rotary welding positioners and often have the fewest moving parts and features. They are capable of operating in flat or horizontal positioning, with most being capable of switching between the two positions. Rotary indexers are used in many precise welding applications and have variable speed controls, including reversing rotation directions. They are often used for welding round objects, although any weldment that can benefit from being rotated to present the next weld to the welder can be more efficiently welded with these machines. If used on their own, they are most effective when working with parts with shorter lengths, or shorter overhangs. When working with longer parts, standard rotary indexers need assistance in supporting the parts due to leverage from the overhang.
Welding Positioner Supporting Methods
There are several tools that work in tandem with rotary indexers, specifically when it comes to supporting larger or longer parts.
Rollers – Rollers are a common tool used when extra support is needed for large parts and can either be powered or idler-type. Powered rollers can roll a part to be welded on their own, however, they may not have the precision of positioning that a rotary indexer has to accurately position a part for an automated welding system. For this reason, idler rollers are far more commonly used with rotary weld positioners. They are best suited to supporting cylindrical weldments, especially pipes, as these are the weldments that would roll the most easily.
Tailstocks – For the biggest, heaviest parts, and parts that won’t roll as easily, tailstocks are often employed to assist rotary indexers. Tailstocks can support weldments of almost any shape, with a chuck similar to the rotary indexer’s that grips onto the opposite end of the weldments. They allow for maximum flexibility when lifting and rotating the largest and heaviest pieces and are often synchronized with the headstock in terms of height adjustment so that the weldment stays level when it is being rotated.
Multi-Axis Indexering Weld Positioners
For the most degrees of freedom available and therefore the best access to every area of the weldment, multi-axis indexers are the go-to tool for many companies looking to improve their welding productivity. Quality of welds is also often improved when using multi-axis indexers, as the increased access to every area of the part allows the welder or automated welder to move the minimal amount, even with non-symmetrical weldments.
Multi-axis indexers have many different variants, including indexers with one mounting position for weldments and multiple positions for several weldments. One of the most common kinds is a double trunnion setup, with a pair of headstocks and tailstocks arranged parallel to each other. This configuration is located on a large turntable that allows the entire configuration to rotate 180 degrees. This is useful when trying to increase productivity, as on one trunnion, a part can be loaded and unloaded while a part is being welded on the other trunnion. When this operation is complete, the positioner rotates 180 degrees and the process repeats itself. This allows for minimal time that the welder or loader spends waiting on the other, decreasing downtime and increasing production levels.
Weld Positioner Options will Often Include:
- Special hole patterns in mounting plates on headstock and tailstock
- Clockwise, counter-clockwise and oscillating index modes of operation
- Can be ordered as complete assembly with head stock, tail stock and base frame
- Different gear ratios
- Customer supplied servo motors – Motion Index Drives to mount
- Mechanical homing devices
- Safety locking devices to be used during maintenance and tooling / fixture assembly
- Variety of encoder or positioning devices
- Slip rings
- Rotary unions
Things to Look for in Welding Positioners and Weld Positioner Manufacturers
Be Sure that Your Weld Positioner Manufacturer:
- Can accommodate all servo motor and robotic motor brands
- Can operate from standard AC motor single or three phase
- Headstock (flexible or fixed index drive, with or without drive motor, servo or AC)
- Tailstock (bearing assembly or thru-hole bearing housing)
- Cusom Risers and Center Frames
- Optional controls drive for motor
- Micarta isolation kits for specific welding applications
- Black oxide head and tailstock mounting flanges
The best weld positioner manufacturers offer features that extend machinery life and reduce operating and maintenance costs. Examples are:
- Flame hardened cams
- Multiple oversized cam followers engaged with cam at all times
- Headstock (flexible or fixed index drive, with or without drive motor, servo or AC)
- Programmable rotation angles of both base rotary movement and dual trunnions
- Fixed central guarding between both trunnion sides
- Fully maintainable with all wear components capable of being serviced at facility
- Very low maintenance components