.....if you take a look at : https://youtu.be/MPNm0Ed83j4 (https://youtu.be/MPNm0Ed83j4)
.....but play the variable/"classic hinged" arm ( short arm-long arm ) , as : www.geocities.ws/iacob_alex/Some_Drafts/text048.jpg (http://www.geocities.ws/iacob_alex/Some_Drafts/text048.jpg)
.....so the maintain a continuous torque difference on the same side of the fulcrum.
Maybe this "small change" can activate the "self"-motion ( pulsatory rotation ) with ? !
Al_ex