first thing I would check is wether you've edited the motor in a time that is different from 0 s.
Infact, if you make a change when the time bar is positioned at a time that is not 0 sec, SolidWorks Motion will intepret it as a change to the value of the rpm's at that time.
Check attached pic: when you see that blue bar next to the rotary motor, it means that the motor has changed its speed from time 0 sec to time 2 sec.
In this case, in order to fix the problem you should cancel the key point at the end of the blue bar, put the time bar at time 0 sec, and then edit the motor: this way the change will occur from time 0 sec and motor wom't change its speed during motion.
Timeline.jpg 66.9 KB
Great, thanks for the help...just what I needed!