Problem

I had been approached by one of the welders to see if there was anything that could be done to optimize the orbital ring welding process. The current process was often done without any fixturing as the fixture the welders used could only fit one size heat exchanger. Ideally an adjustable weld fixture would be able to hold any size heat exchanger and is the kind of fixture that could be ever present at an operators work station reducing the down time needed to retrieve a fixture from elsewhere on the manufacturing floor.

Design

Initial designs took heavy influence from the fixture the welders were currently using as far as constraining the heat exchanger while still leaving room to perform the required welding. The design need to be almost double the width of the current fixture as to be truly universal it would need to be able to hold up to five return bends as that was the maximum featured on any heat exchanger that would require this orbital ring welding. After expanding the footprint of the fixture modifying the design to be adjustable was the next step. Utilizing 80/20 channels and sliding brackets allowed a clamp to constrain the side of the heat exchanger that did not require welding. The design featured a lock on each side to ensure that once the heat exchanger was in place it would not move. I designed this fixture in SolidWorks and was able to develop my design skills in tandem with my assembly skills when working with off the shelf components from suppliers such as 80/20 and McMaster-Carr.

Testing

I was able to test my design in SolidWorks with all of the different heat exchangers that required orbital ring welding to confirm that my design truly was universal. Throughout the entire design process I worked with the operator who had asked for this to ensure that I was meeting his requirements without overlooking any details. 3-D prints of small scale versions of the design confirmed that it would work with the physical models as well. With approval from a team of engineering peers as well as the operators who would be using this fixture we could proceed with the construction of initial prototypes.

Results

After coming to a design that both I and the team were happy with we were able to proceed with the construction of the fixture. Using a combination of off the shelf parts and machined elements we were able to create two instances of the fixture that would become permanent additions to the orbital ring welding cells that would save time and produce higher quality welds moving forward.