Communication cable specialist Quabbin shared with us their report from their in-house Rolling Bend testing on their DataMax Cables.
The focus of this test report is concentrated on the destructive flex forces involved in a continuous motion application. For continuous motion flex testing, there are various experiments available. Many are familiar with the “Tick Tock” test since it has been around for quite some time. The test is named “Tick Tock” because the test fixture’s swing arm moves back and forth through a 180-degree arc similar to the movement of a clock pendulum. Quabbin performed the original flex testing on their industrial Ethernet cables using a “Tick Tock” fixture and received positive results. However, after field observations and experimentations, Quabbin concluded the “Tick Tock” method is a special case because the supported bend cable bend radius is fixed by a mandrel. This is not the typical installation of a cable on a robot arm.
Quabbin believes that a more realistic test is an unsupported rolling bend trial. In an unsupported continuous bend, the cable construction has to prevent the bend from becoming concentrated in a small area. Disruption to a small area can lead to cable failure through nicking because flexing at a kink can cause conductor and shield failure. A robotic arm has reach and exhibits variety in the flex motion that inevitably spreads force over a sizable section of the cable. Simulating these parameters requires a more comprehensive type of flex testing equipment, specifically a device that can simulate a rolling bend. Loosely making the comparison of a human arm to a robotic arm, a rolling bend test can simulate not only the bending of an elbow (like the Tick Tock) but additionally the reach of the arm which in fact turns out to be critical.
- 8753E Network Analyser
- DTX-1800 Portable tester
- Quabbin flex testing machine
For initial setup, it is important to consider safety. Flex machine should remain OFF before testing can begin by making sure the power cord is NOT connected to the outlet. The access door can be unlocked and opened. The following picture indicates how the machine should appear before testing.
When machine is securely OFF, the cable setup can begin. The machine is capable of testing one or two cables at once. If 2 cables have a similar O.D., then it is possible to test them together. Prior to setting up the cables in the flex machine, pins and loads must be installed on both ends of the cables. The testing of the cable follows Quabbin standard procedures. Inserting the cable into the flex machine can begin once the cables are pinned or connectorized.
1 Cable Setup
When only a single cable is being tested on the machine, the following steps should be taken.
2 Cable Setup
If there are 2 cables being tested in the machine, the following steps should be taken.
After the cable or cables are fully secure in the machine, electrical testing can begin. The two tests that are to be performed on each cable are “Return loss” (RL) and “Cross Talk” (NEXT). It is important to first electrically test the cable or cables before flex testing is done. When turning ON the machine the power cord can be plugged in.
When the machine begins to turn and flex the cable, the access door is to be shut and locked for safety. Finally, RL and NEXT testing can begin.
In order to ensure that the cables are able to withstand continuous flexing, data is recorded before, during, and after the test. For 10x flex testing, the halfway point is 750k cycles and the final is 1.25 Million cycles. For 20x flex testing, the halfway point is 5 Million cycles and the final is 10.25 Million cycles. All testing is done while the machine is running insuring that the cable can perform while being flexed in real-time. The testing of the cable follows Quabbin standard procedures. The cables are tested with a radius of 10X and 20X with a rate of 126 cycles per minute.
From the results above, Quabbin Cables can last 10 million cycles! To select your Quabbin cable, visit our page here.