Providing Additional Safety & Accuracy: Custom Fixtures

Tube end forming processes vary in terms complexity. Bent tubing, perpendicularity, surface profiles, datums and more are just some of the geometric variables that can be present in any critical tube end forming projectFor many complex tube end forming processes, the use of custom fixtures may be paramount. A fixture can be a series of mounting points, cradles, and clamps that are used in conjunction to hold a tube in place during the end forming process. 

Custom fixtures provide a range of benefits for a tube end forming project. A primary benefit of a fixture is proper loading. Custom fixtures are ideal for any tube end forming process where the loading orientation in relation to its datums is critical. When working with bent parts, loading without a fixture can be difficult and result in a non-conforming part should the tube be loaded improperly. A custom fixture prevents this problem as there is only one way to load the tube into the fixture. Another benefit of a custom fixture is additional safety. With a fixture, the operator spends less time handling near the loaded tube while the machine is running. In the case of small or short tubes, a fixture will be used as the loading device which will keep the operator’s hands away from the running area.  

Custom fixtures can increase the through-put of a project. In the past, Proto-1 has developed automated fixtures that will shuttle the part to the next process in a streamlined manner. These automated fixtures are quicker than their human counterpart and require less operator interaction with the product. Our in-house engineers can design a fixture to fit any tube. Fixtures are designed based on math models provided by our customers and sample tubes that we scan using our FARO arm to verify. Once the tube is laser scanned, a fixture cradle can be manufactured to accurately fit your production part. 

Custom Ball Flare Shuttle Fixture

The example shown below is an automated ball flare fixture for the RFM-6 tube end forming machine. This bent part underwent two operations before it was complete. The first operation was to trim the end of the tube to provide a clean and square cut prior to the ball flare. After the cut operation was complete, the fixture would automatically shuttle to the other forming station where the ball flare would be form. The fixture itself used a pin that was inserted into a punched hole that was perpendicular to the cut end of the tube. This pin would hold the orientation of the tube once inserted. Cradle points would further secure the tube position and red rubber locking clamps would secure it firmly in place. Orientation of the ball flare to the tube was highly critical for this application and the added use of a fixture provided the accuracy needed for proper loading and end forming. 

Rotating Deburring Fixture 

Fixtures can also be added for ease of use. In this project, Proto-1 designed this custom rotating fixture for a deburring process on 4.5” Ø, 0.118” wall, bent tubing using our RDM-8 tube deburring machineMost tube and pipe can be deburred while hand holding the tube. However, larger tubes with a heavier wall are cumbersome and potentially dangerous for hand loading safelyThe fixture shown below utilized a cradle cut to the profile of the tube which maintained the orientation. From there it was held in place with a series of rubber clamps. The fixture could be maneuvered forward or backward along a set of guide rods and bearings.  Once one end of the tube was deburred, the operator could pull back, rotate the fixture 90°, and deburr the other end in the matter of seconds. This fixture not only increased efficiency and throughput but also improved operator safety since the tubing was held in place by the fixture. 

Final Thoughts

Custom fixtures are a great addition to provide additional accuracy and safety to any tube end forming process. Fixtures can be added to any of our tube end forming lines whether it would be rotary, ram, segmented, tube deburring, or a custom solution For more videos on our fixtures, check our video playlist here.

Do you have a highly tolerance tube end forming project? Contact us today to learn more about our custom fixture solutions for your project.