I am designing a system wherein an assembly has to be moved up and down( 4 inches) at regular intervals ( every 5 mins) using a Linear Actuator. I wanted constrain the DOF and ensure that the entire assembly moves straight up and down( 1-2 degree misalignment is acceptable). The entire assembly is a cantilever and Hence, I wanted to have some bearings to restrict the moment and ensure straight vertical motion.The weight of the entire assembly is about 50lb and the distance from the support frame (for cantilever) is about 7 inches.
Hence, is it okie to have sleeve bearings(Red color in picture below) (Ultra-Low-Friction Dry-Running Flanged Sleeve Bearings from McMaster: http://www.mcmaster.com/#standard-sleeve-bearings/=11vp8eo ) which serves as a guide for the motion
In the above Image, the fixed frame is rigid and the moving assembly( in light pink) slides on the sleeve bearing carriages attached to the fixed frame( in dark pink color)using the guide block attached to the moving assembly( in green). However, since it is a cantilever I want to provide additional support at the other end .Cost & compactness is a factor for me in this design , so are normal sleeve bearings( in RED color- ultralow friction ) good for support the assembly at the other end .