Seconding the avoidance of fan cooled motors.
Other ways include analyzing your system to get the appropriate power requirements. If you can approximate how much torque is required to hold the arm up at a certain point, you can relate that to published data by Vex and see what gearing you’d require to achieve your desired speed and torque while moving the arm, and ensure that it had sufficient holding power. The more you gear a given motor, the happier it will be holding position, but your speed will be affected inversely to the increase in torque from gearing (and thereby, decreasing the current draw to your motor, which is what kills it in the first place).
What you should take away from that, is that if your motor and gearing simply don’t have the power to accomplish what you’re asking of it, you can’t program anything to solve that. At that point, if you don’t want to change gearing, you should go the route of adding in mechanical solutions to assist the motor like @Jon_Stratis said.