Igus Chain For Rotary Motion

Published on July 8, 2013
Channel: John Briggs
Category: Education
Source: Youtube

I need an IGUS chain (cable carrier) to rotate through 450°, but thought I would get started with this one that has 180° of motion. The parts all come from an IGUS download of an RBR chain (bends in both directions). The assembly was made of 5 links of chain at a time with pin joints between them. The groups of five links were then joined with pin joints to each other. By creating a group of five, you can save a lot of time over creating each pin joint individually. Then cam surfaces were created between the four guides and "Race Track" lines drawn on the outside of the links. The cams were created with "lift-off" enabled. I doubt that the behavior is correct because I don't have any mass modeled and perhaps more importantly I didn't model the friction at the joints. Never the less, the model shows some of the possible bad behaviors of the IGUS chain in this configuration and why the middle guides are needed. One thing that still bothers me is that the middle guides don't seem to work optimally. Ideally, the guides should always be in a position to support the cable chain, but for much of the angle of rotation, the middle guides are not capable of supporting the cable chain. This has to do with the angular kinematics. Ideally, the inner guides with be rotated at some ratio to the inner cylinder so that they were always at the optimal position.