Belt coming off
Yes , in due course the belt can be worn out of the edges and so can SLIP through the pulley when there is load. Examine the belt carefully and check for the wedge damage, If so replace the belt, However if you have a problem to source, then you can try and use an emery paper to roughen the belt , clean the pulley, check on the alignment of the motor and main pulley and if the belt is slightly loose you can use some insulation tape on the pulley as a test solution before you source the right belt , so as to increase the diameter of the pulley to stretch the belt.
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