Electric Actuator/Slider Type Ball Screw Drive/Series LEFS Model Selection 100 W L1 Mep m Work load: W [kg] Speed: V [mm/s] 20 15 10 5 0 0 100 200 300 400 500 600 700 Lead 12: LEFS25A Lead 6: LEFS25B (LEFS25/Step motor) 2,000 1,500 1,000 500 0 0 5 10 15 20 Work load [kg] Overhang: L1 [mm] 5000 mm/s2 3000 mm/s2 1000 mm/s2 T1 a1 a2 L Speed: V [mm/s] Time [s] T2 T3 T4 Step Motor (Servo/24 VDC) Servo Motor (24 VDC) !Workpiece mass: 5 [kg] !Speed: 300 [mm/s] !Acceleration/Deceleration: 3000 [mm/s2] !Stroke: 200 [mm] !Mounting orientation: Horizontal upward !Workpiece mounting condition: Calculation example) T1 to T4 can be calculated as follows. T1 = V/a1 = 300/3000 = 0.1 [s], T3 = V/a2 = 300/3000 = 0.1 [s] T2 = L . 0.5 ・V・ (T1 + T3) V = 200 . 0.5 ・ 300 ・ (0.1 + 0.1) 300 = 0.57 [s] T4 = 0.2 [s] Therefore, the cycle time can be obtained as follows. T = T1 + T2 + T3 + T4 = 0.1 + 0.57 + 0.1 + 0.2 = 0.97 [s] Selection Procedure Check the work load.speed. (Pages 2 and 3) Check the cycle time. Based on the above calculation result, the LEFS25RA-200 is selected. Check the guide moment. Select the target model based on the workpiece mass and speed with reference to the . Selection example) The LEFS25RA-200 is temporarily selected based on the graph shown on the right side. Calculate the cycle time using the following calculation method. Cycle time: T can be found from the following equation. T = T1 + T2 + T3 + T4 [s] !T1: Acceleration time and T3: Deceleration time can be obtained by the following equation. T1 = V/a1 [s] T3 = V/a2 [s] !T2: Constant speed time can be found from the following equation. T2 = L . 0.5 ・V・ (T1 + T3) V [s] !T4: Settling time varies depending on the conditions such as motor types, load and in positioning of the step data. Therefore, please calculate the settling time with reference to the following value. T4 = 0.2 [s] Step 1 Step 2 Step 3 Step 1 Check the work load.speed. Step 2 Check the cycle time. Step 3 Check the allowable moment. . If the step motor and servo motors do not meet your specifications, please also consider the AC servo specifications (Page 16). T1: Acceleration time [s] Time until reaching the set speed T2: Constant speed time [s] Time while the actuator is operating at a constant speed T3: Deceleration time [s] Time from the beginning of the constant speed operation to stop T4: Settling time [s] Time until in position is completed Selection Example Operating conditions L : Stroke [mm]・・・・・・・・・・・・・・・ (Operating condition) V : Speed [mm/s]・・・・・・・・・・・・・ (Operating condition) a1: Acceleration [mm/s2]・・・・ (Operating condition) a2: Deceleration [mm/s2]・・・・ (Operating condition) 1