1-The length of the arm 30 inch
2- the radius of the ring should be 37.5inch no

1-The length of the arm 30 inch
2- the radius of the ring should be 37.5inch no more to fit the box and the circle width 3.70 inch
3- inside the ring there’s gonna be a timing belt or customize chain with 4 holes on it that will be screwed to the cylinder to have full 360 degrees rotation
4- the cylinder going to be inside the box the arm should go inside the box and screw down the customize chain to the cylinder hole
5- the upper plate of the arm and ring it prefer to be removable
6- I will attach the box and cylinder file