Randall,

For the maximum belt slope angle, you have to obtain the angle of rupture (internal friction angle) of the material sliding on itself and the wall friction or wall sliding angle between material and belt. Which ever is less controls the belt incline angle. Remember to factor for dynamic conditions of idler bounce.

Have you read these and their references wrt Carr?

http://www.jenike.com/pages/educatio...lowability.pdf

http://www.e1.greatlakes.com/content/antec2001.pdf

Lawrence Nordell

Conveyor Dynamics, Inc. ■