 Hello everyone. In this video I want to talk about belts. Belts are another method of power transfer, how we can move or transfer torque from one shaft to another, and they're used fairly commonly in a lot of different machines. So belts can take a variety of formats. Usually we have that power being transferred from one shaft to another. And like using gears and things like that, they provide mechanical advantage, trading rotational velocity for torque, which is a common use. We can also have things such as tensioning systems, methods to keep the belt tensioned as it perhaps lengthens over time as it's under load for a long period of time. And belts in general can be either flat or they can be V-shaped. Flat belts would generally be used in higher speed applications. V belts would be used in applications where the speed isn't as high, but we want, you know, more power transmission capability. When we're designing a belt, usually the point that we have to look at is the smaller of the two pulleys that the belt is wrapped around. So in the example on the screen, the pulley on the left would be smaller, and therefore that's where we would need to watch out for slippage that could occur between the belt and the pulley. And the reason generally for that is that the wrap angle around the pulley is less. So we can see that on the larger pulley, the belt wraps around more than 180 degrees, so more than half of the pulley, whereas on the smaller pulley that's on the motor here, it's wrapping something less than 180 degrees. So just, you know, purely due to geometry, we have to take into account where we expect failure to occur. So I mentioned that V-belts were a commonly used shape. This just gives some example geometry of a V-belt, and we'll talk more about that in the next video. But generally, you know, the forces that are involved in a V-belt provide a little bit greater clamping force, and therefore torque transmission than just for a flat belt. We could also talk about timing belts. So timing belts are a variation on a belt, where we have gear-looking teeth, both in the pulley that the belt is wrapped around, and on the belt itself. That pulley or those teeth allow for there to be no slippage between the belt and the pulley itself, and therefore allows them to stay in sync with each other, hence this, you know, timing belt name. It reduces the tension requirement in the belt, so we don't have to have as much tension, and thus reduces loads on the shaft. But of course, you know, comes at the expense of costing more money, expensive greater expense, I guess is what I'm saying there. And just a little bit more difficulty in in the manufacture. Of course, not something we'll directly look at in very much depth, but related to belts would be chain or chain drive. A chain is, you know, usually made out of metal components. Of course, there are plastic chains as well, but metal components would be the most common, and they are going to be longer lasting than a belt in general. They would wear less frequently. The wear that they do experience can cause changes in the tension of the chains, so therefore, tensioning systems are sometimes needed, because as they wear that tension decreases. And there are, of course, ASME standards for sizing of chains and the associated sprockets and such that go with them to allow for dimensional compatibility across various manufacturers. So that's a brief overview of belts and a little bit on chains. I'll get into more detail on analysis in the next video. Thank you.