how we test the new base joint RL-90-BL1

One important aim for our development was to achieve higher loads for our robolink arms. Especially the torque for the pivoting movement is decicive for the capacity of the arm. We measure the breaking torque on our ZWICK puch/pull test device. The base joint RL-90-BL1 is fixed on the unit, by pulling the wire we lift rising loads and wait for the first failure. In this case, the nipple from the wire had been torn out at ~2.000 N. The joint itsself is not damaged at all.

For this test we measured a lifting force of ~80 Nm (14,5 kg at 0,55 arm length). For the difference between a static test and dynamic application we assume a factor 3 for the calculation. In addition with a safety factor we set the catalogue value at 20 Nm max. load for the pivoting movement. We will try to reach at least 24 Nm by modification of the nipple fixation in the near future.

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test installation

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test results


(maybe you wonder why the test part is white: we used a first protototype for the test. Produced by laser sintering (SLS). The product will be black in the end, but also be produced the same way.)

NEWS for Hannover fair 2013: new base joint RL-90-BL1

The basic idea for this development is the wish to be able to build up a 6 DOF robot. For that purpose, a strong “base joint” was needed. It had to be stronger than the previous versions, and it should be able to lead the wires and cables of at least 4 more DOF inside, as well as additional pneumatic and/or electric cables.

The new joint is based on igus’ “PRT-01-50” slewing ring bearing. It has 2 DOF (degres of freedom): 1) rotation (+/-90°), 2) pivoting movement (+/-90°).

At this year’s hanover fair (08.04.13-12.04.13) we will present this base joint in a 6 DOF robot arm. Today you can watch 2 videos: 1) first kinematic test of the 2 DOF base joint RL-90-BL1 and 2) first test run of a 6 DOF installation, with 2 more robolink joints.