The cranks are broken

Hello,

We'd be happy to help but since the spline that the handle attaches to appears to be broken, the entire operator assembly will need to be replaced. We should be able to supply the parts that you need but I can't quite make out the details of the arms that move the sash through the screen mesh. If you could remove the screen and show us a clear top-down photo of the operator arms, that will help us narrow down your options. Thank you!