So of my 5 boys one of the eldest decided to re enact some of their youth on their youngest brother’s toy. This resulted in a crippled worm rocker. But dad has a 3d printer and a pair of calipers and with designspark 2.0 from http://www.rs-online.com/designspark/electronics/eng/page/mechanical i might have a workable replacement. If the youngest tests and approves of these I will be posting and sharing the stl to solve other crippled worm problems
2.0 survived the weekend. So here is the lin for the file. https://www.youmagine.com/designs/caterpillar-rocker-antenna