__Step 4 : Rotary Indexer Model Selection__Minimum Follower Wheel Pitch Diameter (Credit : Sankyo) |

- Recommended Size of Rotary Indexer can be estimated. By calculate Radius of Gyration divide by Follower Wheel Pitch Radius, this value should be less than 5 (this value may vary depend on difference manufacturer)

Recommended Follower Wheel Pitch Radius of Rotary Indexer |

- Minimum Follower Wheel Pitch Radius, [PR
_{min}] = 427/5 = 85.424 ≈ 85.4 mm - Then, Minimum Follower Wheel Pitch Diameter, [PD
_{min}] ≈ 85.4 x 2 ≈ 171 mm

- Recommended Size of Rotary Indexer also can be estimated by another method. By calculate Table Diameter divide by center distance between input & output shaft, this value should be less than 7 (this value may vary depend on difference manufacturer)

Distance Between Input & Output Shaft |

Recommended Center Distance between Input & Output Shaft of Rotary Indexer |

- Then, Minimum Distance Between Input & Output Shaft, [CD
_{min}] = 1000/7 = 142.857 ≈ 143 mm - Total Output Torque for Indexer Selection, [T
_{t select}] = T_{t}x SF = 307.271 x 1.2 = 368.726 ≈ 369 N.m @ Input Shaft(camshaft) Speed 60 rpm

**Thus, Select Indexer that Dynamic Rated Output Torque [T**

_{op}] is more than 369 N.m at input shaft speed more than 60 rpm, 8 stops, Indexing Angle 270 degree, MS motion curve, minimum center distance between input & output shaft 143 mm and minimum follower wheel pitch diameter 171 mm

**Step 5 : Gear & Motor Selection****F**

**ind the maximum torque on gear output shaft at working shaft speed**

- In this case, gear is directly connect to the rotary indexer. Then the maximum torque on gear output shaft is equal to the camshaft torque of rotary indexer
- The camshaft torque of rotary indexer[T
_{c}] is determined by following formula:

Rotary Indexer Cam Shaft Torque |

- Internal Indexer Inertia Torque, [T
_{oi}] = 2.943 N.m (from rotary indexer manufacturer data) - Camshaft Friction Torque, [T
_{x}] = 16.677 N.m (from rotary indexer manufacturer data) - Maximum Camshaft Torque Coefficient, [Q
_{m}] = 0.987 (This is standard value, find the Qm for Modified Sine Cam Curve from Cam Curve Characteristic Table) - Then, Camshaft Torque, [T
_{c}] = 87.552 N.m @ camshaft speed 60 rpm (This is the torque at input shaft of rotary indexer which is equal to torque at output shaft of gear)

**Next, calculate the equivalent camshaft torque for gear selection [T**

_{ce select}] by considering of operating condition & safety factor- Calculated Operation Factor, [f] = 1.8 (Calculate from type of load(steady or shock load), operating hours per day, frequency of starts/stops, ambient temperature, type of lubrication or others factor. Please check gear manufacturer information. In this case use 1.8)
- Then, T
_{ce select }= T_{ce}x f x SF = 87.552 x 1.8 x 1.2 = 189.113 N.m @ Output Shaft Speed 60 rpm

**Calculate Gear Input Shaft Torque**

- Gear Ratio, [i
_{g}] = 10.33 (Check from gear manufacturer info.) - Gear Input Shaft Speed, [N
_{g}] = N_{rpm }x i_{g }= 60 x 10.33 = 619.8 ≈ 620 rpm - Gear Running Efficiency, [Eff
_{g}] = 92% (Check from gear manufacturer info.) - Gear Input Shaft Friction Torque, [T
_{xg}] = 0.9 N.m (Check from gear manufacturer info.) - The Gear Input Shaft Torque[T
_{g}] is determined by following formula:

Gear Input Shaft Torque |

- Gear Input Shaft Torque, [T
_{g}] = 10.113 N.m @ Input Shaft Speed 620 rpm

**Calculate Motor Torque**

- Motor Revolution per Minute, [N
_{motor}] = 1730 rpm (from motor manufacturer data) - Gear Ratio Required, [i
_{req}] = N_{motor}/ N_{rpm}= 1730 / 60 = 28.833 - Pulley Speed Ratio, [i
_{pulley}] = I_{req}/ I_{g }= 28.833 / 10.33 = 2.791 ≈ 2.8 (←if very close to 1, motor can be mounted directly to gear, then set Eff_{pulley}= 100% & T_{xp}= 0

Table Drive Application with Pulley (Credit : Sankyo) |

- Pulley Running Efficiency, [Eff
_{pulley}] = 90% (estimated) - Pulley Shaft Friction Torque, [T
_{xp}] = 2 N.m (estimated) - The Motor Torque [T
_{motor}] is determined by following formula:

Motor Torque |

- Then, Motor Torque, [T
_{motor}] = 10.003/(2.791 x 0.9) + 2 = 6.026 N.m @ Speed 1730 rpm

**Calculate Motor Power**

- The Peak Motor Power [P
_{motor peak}] is determined by following formula:

- Then, The Peak Motor Power [P
_{motor peak}] = 2 x 3.1416 x 1730 x 6.026 / 60 = 1091.617 Watt ≈ 1.092 Kw

**Calculate Motor Power for Motor Selection**

- Power for Motor Selection, [P
_{motor sel}] = P_{motor peak}x SF = 1.092 x 1.2 = 1.310 Kw

**Then, select gear that maximum continuous output torque is more than 189 N.m at output shaft speed more than 60 rpm, gear ratio 10.33**

**Motor power 1.31 Kw at speed 1730 rpm**

**Ratio of pulley between gear and motor 2.8**

- Example of Rotary Indexer Sizing Calculation for Table Plate Drive Application Part 1
- Example of Rotary Indexer Sizing Calculation for Table Plate Drive Application Part 2

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