Quabbin provided us with another test report that complements the Rolling Bend Flex Test Report which can be found here. This test shows the results of torsional stress on their DataMax® cables. Read on to see how many cycles the cables withstood!
Introduction
Continuous movement applications that force a cable to flex repeatedly will
subject the cable to various types of stress that can degrade performance and cause failure in the field. The most commonly recognized type of flex stress is the act of repeatedly bending a cable back and forth. This back and forth flexing is detailed under separate cover in the Quabbin, Rolling Bend Flex test report. However, a rolling bend isn’t the only type of flex stress. The second lesser-known stress called torsional stress can also be at work in a continuous movement application. The focus of this report is torsional stress and the impact on the Quabbin Industrial Ethernet products.
As previously explained in the Quabbin, Rolling Bend Flex test report, the testing has been designed to simulate the movement of a robotic arm. If we can use an analogy, the rolling bend flex cycle represents the bending and reaching of the robotic arm as it emulates a human arm bending at the elbow and possibly straightening to extend and grasp something. The scenario covers two of the three types of flex stress yet still leaves us to account for the third, torsional stress. Using the same analogy as above, we would see torsional (or rotational) stress come into play as wrist rotation. Just as a human arm includes a wrist capable of rotation, a robotic arm also needs to accommodate wrist-like motion for positioning tools and/or to grasp objects. As the “wrist” rotates through the full field of motion, it can twist a control cable up to 360 degrees, similar to the visual picture of wringing out a wet towel. Obviously, these torsional forces must be considered during cable development in order to have a design robust enough to survive the intended purpose. Hence we arrive at the Quabbin Industrial Ethernet Torsion Test.
Torsion tests were performed on Quabbin industrial Ethernet cables. The test is a 360-degree twist total per cycle (180° in each direction) over 34” of cable at 71 cycles per minute.
Testing Equipment
- 8753E Network Analyser
- DTX-1800 Portable tester
- Quabbin torsion testing machine
Resources
Torsion testing is done on the following Quabbin cables: 5025, 5026, and 5083.
Setup
Weight is added to the lower carriage to keep the cable taut. The lower carriage can move as the cable is twisted and becomes shorter to avoid breaking the cable. The test is set to a 360-degree twist total per cycle (180 in each direction).
Test Description
In order to ensure that the cables were able to withhold continuous 360-degree rotation, data is recorded before, during, and after the torsion test. The halfway point is 1.5 Million cycles and the final is 3.25 Million cycles. All testing is done while the torsion machine is running insuring that the cable can perform while being rotated in real-time. The testing of the cable follows Quabbin standard procedures.
Results
As you can see, Quabbin cables pass the torsion test for tough applications and high-cycles. Be sure to check out Quabbin DataMax® Cables here.
