Back during your engineering school days, most of us took a strength of materials course and learned about cantilevers. In this post, we will review a basic formula for cantilevers and introduce you to a shaft series that MISUMI carries, called cantilever shafts. We will also take a look at a few applications utilizing them.
Cantilever: a rigid structure anchored only on one end. Cantilevers are used in structural engineering in a variety of ways. They are even as simple as a coat hook, a horizontal flag pole, or a street light. It is important to calculate the maximum amount of load the structure can handle at the end of the cantilever. This is determined by several formulas based on the load, shape, length, and material of the cantilever. The degree in which the rigid structure is displaced under force or load is called deflection and can be calculated with the formula below. There are a variety of types of loads for cantilevers as the world is not as simple as one load, therefore, calculations are typically accomplished via finite element analysis as hand calculations can be time-consuming and human error can occur. The simplest of calculations can be found with the force being applied at the end of the cantilever beam.
F = Force
L = Length
E = Young’s Modulus
I = Moment of Inertia
Young’s Modulus will depend on the material properties and the moment of inertia depends on the shape’s cross-section.
While MISUMI is a mechanical and electrical parts provider and manufacturer, we do provide cantilever shafts for your rotary motion applications or for any application you may require them for. They act the same way a cantilever beam would, mounted on one end only with the rest of the shaft protruding out. All calculations apply in the same manner to these cantilever shafts except the cross-section is round. MISUMI cantilever shafts are made of steel or stainless steel. There are a variety of mounting styles available such as nut mount, screw mount and flange mount in both inch and metric units.
Special coatings are available as well, electroless nickel plating and black oxide. Typical use of cantilever shafts are for rotary power transmission applications with timing belts and pulleys. The shaft connects from the mounting structure to the timing pulley. The driven pulley is attached to the cantilever shaft. They can be used with gears and chains as well or to mount 2 pieces in line together as in the example below.
Here are a few examples of cantilever shafts used in rotary applications.
The first application shows a cantilever shaft connected to the mechanism that moves the workpieces down the roller chute. It allows for the mechanism to be in the center of the chute without interference. As you can see, the cantilever is supported on one end by the bracket while connected to the center mechanism. All MISUMI components are in yellow.
The second application shows its use with a rotary bearing connected to a linear bushing and shaft. The cantilever shaft allows the bearing to be located on the same level as the moving work piece. This cantilever shaft uses the flange mount style being mounted to the bottom plate and extending up to the bushing. For more applications using cantilever shafts, check out inCAD Library which houses hundreds of free application examples using MISUMI products.
MISUMI cantilever shafts are fully configurable for your application needs allowing you to be flexible in your design. You can choose the length and diameter on each mounting types configurator page. Be sure to check out our YouTube series on MISUMI’s shafting: linear, posts, and rotary here! If you missed last week’s post on MR vs. GT timing pulleys, check it out here!