 Myself Sachin Rathore working in mechanical engineering department from Walton Institute of Technology, Solapur. Today we are dealing with selection of the belt from the manufacturer in data book. So it is a part 3, already we have seen the part 1 and part 2. In the part 1 we have seen the basic concept of the belt and the type of the belt. In the part 2 we have seen what is the design procedure of the belt and today we are going to see how to design the belt. So it comes under the course Machine Design 1. So the learning outcome at the end of this session the learner will able to design the flat belt from the manufacturing catalog. So if you consider this numerical see that the numerical is it is required to select a flat belt drive for a fan running at 360 rpm which is driven by 10 kW and 1440 rpm motor means that given us the input speed and the power and the output speed we are getting at the fan is 360 rpm. The belt driven is open type and the space available for a center distance of 2 meter approximately. The belt velocity should be between 17.8 to 22.9 meter per second. The power transmitting capacity of the belt per mm width per ply at 180 degree arc of contact and at the belt velocity of 5.08 meter per second is 0.0118 kW. The load correction factor can be taken as 1.2 suggest preferred diameter for the motor and the fan pulley and give the specification of belting means here in these questions we are going to design the flat belt drive means we are just producing the complete specification of the belt that we are going to use in between the fan and the motor. So these are the given data. So the first step calculate the pitch diameter of the pulley. So we can consider the belt velocity is 18 meter per second. You can consider any value that is ranging from 17.5 so here in this question only they had given us the belt velocity between 17.8 to 22.9 meter per second that's why we assume that the belt velocity is 18 meter per second. So by considering this 18 meter per second and the input speed we are knowing we are getting the diameter is 238 mm we are getting the diameter of smaller pulley is 238 mm. So we have to select the standard pitch diameter from the manufacturing data. So this is a data book so in which we have to select the proper diameter of the pulley as we are getting the diameter is equal to 238 so we have to check out whether it is available or not. So it is not available we have to select the diameter of smaller pulley as 250 mm. So from the manufacturing data take D is equal to 250 mm. So by using this equation you have to calculate the value of capital D as we are knowing the input speed at the output speed of the pulley and this diameter is 250 mm calculate the value of diameter of larger pulley capital D. So by putting this value we are getting capital D is equal to 1000 mm so yes it is available. So step number 2 is calculation of corrected velocity of the belt. So you can pause this video and think a while is there need to calculate the corrected velocity? Yes we have to calculate the corrected velocity here because we have selected the diameter of the smaller pulley from the design data book we are not taken as a 238 we have selected as a 250 so there will be the we have to calculate the v corrected. So by putting the value of small d n1 you have to calculate the corrected velocity. So here we are getting the corrected velocity is 18.85 m per second. Step number 3 calculation of load correction factor F A from the manufacturing data. So as per your the applications we have to find out the value of load correction factor F A. So as we are going to use the motor for running the fan we have to select the F A is equal to 1.2. Step number 4 calculate angle of contact for smaller pulley that is also called as a wrap angle alpha s. So by using this equation we have to calculate the value of alpha s. So just put the value of capital D small d and c calculate the value of alpha s. So it comes 158.39 degree. Step number 5 find the arc of contact factor F D from the manufacturing data book. So this is a tables I have taken from the manufacturing data book. So in which we have to calculate the F D. So as we are getting the value of alpha s is equal to 158.39 so it is the value is ranging from these two value it is in between 150 and 160. So you will get the value of F D in between 1.13 to 1.08. So here we have to use the interpolation formula and find out what is the value of F D at an angle of 158.39. So by using the interpolation formula you will get F D is equal to 1.088. Step number 6 calculate the design power. So the design power is calculated by this equation P D is equal to actual power into F A into F D. So you will get the design power is equal to 13.056 kilowatt. Step number 7 calculate the power rating of the belt PR. So as we are going to use the high speed belt because they had given us this data as they had given us for 5.08 the power rating is 0.0118. So we are going to find out the power rating for your actual application. So PR is equal to 0.0118 divided by 5.08 into the V corrected. As already we got the V corrected is equal to 18.85 put this value calculate the value of PR. So here we are getting the value of PR is equal to 0.04376. Step number 8 calculate the width of the belt. We can calculate the width of the belt by referring this equation W is equal to P D that is the design power divided by rated power into number of plies. So this total width we have to find out for that purpose we have to select the number of plies whether we have to use the 3 plies, 4 plies, 5 plies. So these are the tables from these tables we have to select the number of plies. If we have selected the number of plies equal to 3, if you put here number of plies equal to 3 and this P D and PR we are knowing put this value and calculate the width. So here we are getting the width is equal to 99.38 for 3 plies. So we have to check out this table for the 3 plies the width is not available yes. So if you are going to use the 3 plies so definitely the failure is going to occur. So we can move for the next that if the number of plies equal to 4 put down here number of plies equal to 4 and put the value of PR and P D calculate the W. So the W we are getting 74.52. So we will check here for the 4 plies yes it is available that width. So we can use the number of plies equal to 4 in which the width is 76, 76 mm right. So like this we are finding the width and the number of plies in this current step. Step number 9 calculate the length of the belt. So as we are knowing that we have to design the open belt drive. So this is the equation for finding the length of the belt in the open belt drive. Calculate the L as all the values we are knowing C is the centre distance capital D and the small D are the diameter of larger and smaller pulley put this value and calculate the L. So we are getting L is equal to 6057 mm. So this is the length of the belt. So by the above steps the design solution will be obtained as first one diameter of smaller pulley D is equal to 250 mm, second one diameter of larger pulley D is equal to 1000 mm, third one width of the belt W is equal to 76 mm, fourth one number of plies N is equal to 4 and the length of the belt is 6057 mm. So we have to find out the specification of the belt. So the specification of the belt is 6057 mm length of 76 mm width and 4 plies high speed belting. This is the specification of the belt. So this belt we are going to use in between fan and motor. So this will give you the brief idea regarding the selection of the belt from the manufacturing data. So I have taken the reference of the VB Bhandari book. Thank you.