Innovation in Weld Fixturing

Having a well-designed workflow is critical to keeping weld cells busy and productive. Implementing a series of sub-assembly cells that feed work to a larger, final weld cell can be an effective way to manage the flow in a welding shop.

This approach can greatly increase efficiency, if done properly. But it can be a difficult workflow to implement and there are several issues to consider. If the sub-weldments are not made accurately, there will be fit up problems in the final weld cell. This means rework, which turns into more lost time for the welder or robot in the final cell. Another potential issue is keeping the sub-weldment cells producing parts fast enough to keep up with the demand in the final weld cell.

In order to be successful, the sub-assembly stations must have precision tooling. With accurate tooling, every part coming out of the weld cell will be within tolerance. And with a consistent process based around the tooling, the rate of completed parts can be controlled to match the needs of the downstream cells. Another benefit of producing repeatable and accurate sub-weldments is that less tooling is needed in the final weld cell, further reducing overall solution cost and setup time.

Dedicated tooling that is designed for a specific family of parts can be used to achieve these results. However, dedicated tooling can become very expensive because each fixture becomes obsolete once the cell is changed over to make a different part. Having to rely on long lead times for making dedicated tools can also hurt a company’s ability to respond quickly to job opportunities.

The better solution is to use modular fixturing in each of the sub-stations. Modular workstations allow for an infinite number of parts as jobs change over the years.

http://youtu.be/_GdYNfr5mWI

And since the workstations are designed with a catalog of standard modular components – including angles, stop bars, spacer disks and clamps – new fixtures can be setup from scratch within a couple of hours. The tooling can be customized to support all types of welding applications.  With the ability to quickly set datum locations within ±.30 in and repeat setups within ±.005 in, parts will be within tolerance every time with no costly re-work delays.

Compared to larger modular welding tables, modular workstations are smaller and lighter weight; features that make them well-suited for sub-assembly production. Depending on how the overall workflow is setup for the shop, these cells can be on stationary bases or mobile carts if the work pieces need to be moved in an assembly line type of process.

While modular workstations are well-suited for sub-assembly manufacturing, they may not be the right solution for every welding project. For example, due to the lighter-weight structure of the bases, they may not have the capacity to support heavier parts. And unlike large, 5-sided modular welding tables, workstations do not have the ability to be expanded to handle parts that are longer or wider than the footprint of the work surface. They are best suited to weld cells that can be setup to always work on smaller parts and sub-weldments.

http://youtu.be/HQX9mUBXzLs

Companies that are looking for an affordable introduction to modular tooling should also consider a modular workstation. The tooling components are compatible with larger modular welding tables, so the initial investment is re-usable for bigger projects in the future.

When choosing a modular fixturing system, make sure 3D CAD models of the tooling are available to support off-line fixture design and work instructions. It is also helpful to have support from the tooling supplier to provide initial tooling package selection, as well as training for fixture designers, fitters and welders on how to use and work with the system.

Brian Dodsworth is the sales manager for Bluco Corporation, 3500 Thayer Court, Aurora, IL 60504, 800-535-0135, info@bluco.com, www.bluco.com, which has specialized in the design and implementation of modular fixturing solutions for over 25 years.