Power file 9032
I mention the Makita sander here, as this is the one that I use and have found to be a comfortable and efficient sander, I use this both in the workshop for shaping the handrail components and out on site for adjusting and shaping parts.
When the sander comes, it is supplied with sprung cork beds that the belt runs over, this is to keep the belt flat during operation.
I normally remove the bed on the top of the arm, this allows the belt to bend, by using the top of the belt, dependant on pressure applied and how close to the front bearing you use the belt, you can get a curve in the belt to follow the curve you are trying to shape.