 Hello, my name is Sachin Rathore working in mechanical engineering department from Walsh University of Technology, Sollapur. So today we are dealing with the selection of belt part 2. In previous lectures, we had seen the basic terms behind the or the basic knowledge of the belt. So in this today's lectures we are going to see how to select the belt from the manufacturing catalog from the course Machine Design 1. So the learning outcome of this session is at the end of this session the learner will be able to select the flat belt from the manufacturing catalog. So there are the 8 input data parameters we required before we are going to design the flat belt. First one, power to be transmitted, second input speed, third one output speed, fourth one the center distance that is the center distance between a two shaft belt velocity, belt system whether the open belt or the cross belt system that we are going to use. This condition means for which application we are going to use the belt drive and the eighth one is a manufacturing data. So the design procedure for the flat belt drive. Step number one, we have to calculate the pitch diameter of the pulley. So we have to find out the d, the small d indicates the diameter of smaller pulley. For the selection of the diameter d we have to select the diameter from the standard data book. So for finding the diameter d at least you should know how much diameter we required. So we have to calculate by knowing the equation v is equal to pi dn by 60. By using that equation you can easily calculate diameter of smaller pulley. So in which we have to consider the belt velocity. So generally the flat belt velocity is ranging from 18 meter per second to 25 meter per second. So we have to select any belt velocity and you have to calculate the value of d. So as you are calculating the diameter of the smaller pulley so we have to check out the design data book. So these are the preferred diameter. So whatever you are getting the value of small d by the calculations so we have to check out from this data book. So you can think that why we have to select the diameter from the given table. So as this diameter of the pulley are already manufactured or it is already available so we can prefer this data and you are going for that pulley diameter. If suppose the pulley diameter by the calculation that is v is equal to pi dn by 60 if we are getting the d is equal to 135 then at that time we can prefer the diameter of the pulley is equal to 140 mm. Next we have to find out the value of capital D that is the diameter of larger pulley. So we are knowing the equation that n1 by n2 is equal to capital D by small d that is the speed ratio of input pulley to the output pulley is equal to diameter of output pulley divided by diameter of input pulley. As we are knowing the input parameter that is n1 and n2 already we got the value of d you can easily calculate the value of capital D. Step number 2 calculation of corrected velocity or corrected velocity of the belt. So here we have to calculate v corrected is equal to pi dn1 by 60. So already we have made one assumptions that v is equal to 18 meter per seconds as we are selecting the diameter from the standard data book so definitely the velocity is going to change so that is why we have to select the corrected velocity. Step number 3 calculation of load correction factor from the manufacturing data book that is indicating by the letter F a. So this is a table for selection of the correction factor. So depending upon your the applications we have to select the F a value as the load is normal we can select the F a is equal to 1. If you are using the centrifugal pump fan light machine tool conveyor at that times we have to select the 1.2. If heavy duty fans are there compressors are there we can check out for the 1.3. If the shocks loads are there at that times we have to take F a is equal to 1.5. Step number 4 calculate the angle of contact of the smaller pulley. So it is denoted by the letter alpha s so the angle of contact of the smaller pulley is nothing but the portion of the pulley are going to contact with the belt. If you consider the smaller pulley how much portion of the belt are going to contact with the smaller pulley that angle we have to find out. So by using these equations we have to find out the alpha s value that is also called as the wrap angle of the smaller pulley. So as already we had calculated the value of capital D small d c is the distance between two shafts that is the input data we are knowing you have to calculate the value of alpha s. So this equation we are using for the open belt drive and for the cross belt drive just we are placing here the plus sign in between the capital D and small d. So by using this equation you have to calculate the wrap angle of the smaller pulley. So as we are knowing the wrap angle you have to calculate the contact factor arc of contact factor fd from the manufacturer in data book. So I have taken this table from the manufacturer in data book only. So as per your the alpha s you have to select the value of fd. So if the alpha s is 170 you have to take fd is equal to 1.04. Step number 6 calculate the design power. So we have to calculate the design power by using this equation pd is equal to p that is actual load into fA into fd. Step number 7 calculate the power rating of the belt PR that it is comes by kilo Watt per mm per ply of the belt. Step number 7 is calculate the power rating of the belt PR in kilo Watt per ply per mm of the belt. So this is a equation for finding the PR. It is used for the high speed belt and this equation for the fourth belt. So in this equation this equations we are getting suppose we are using the high speed belt at 5.08 meter per second velocity the power rating is 0.0118. So we have to calculate the actual power rating for that much corrected velocity. Step number 8 calculate the width of the belt it is denoted by the letter W. So W is equal to pd divided by PR into number of plies. So if you observe this will gives you the total width. So we have to select the total width for selecting the total width you should know how many number of plies you require. So these are if you suppose consider this diagram there are 1, 2, 3, 4, 4 plies going to use. So we have to check out for these number of the plies whether the width are available or not. So according to that we have to select the number of plies for availability of that width. Step number 9 calculation of length of the belt. So we are using this equation for the open belt drive for finding the length of the belt and for the cross belt drive we are using this equation. So you have to calculate total length of the belt. So by the above steps the design solution will be obtained as first one we had calculated the diameter of smaller pulley, we had calculated the diameter of larger pulley, the width of the belt, number of plies and the length of the belt. So I have taken the reference as a VB Banda Rebook. Thank you.