Roborock s7 bumper tensioner

My roborock s7 was giving me many "Error 2" messages. This was caused because the main bumper did not return to its original position due to the weak springs in the front and the optical sensors itself. This part tries to fix it by giving the bumper a little bit of tension on the sides. 

It is the first iteration so i don't expect to work for a long time: crashes may dislodge it. 

Print laterally (for best mechanical strenght when tensioning), with the side of the prong touching the bed