Applied Force and Component Selection

Sometimes the best way to selecting the right component for an application is to base your choice on what it needs to do. In other words, start with the motion or action required of the operator, considering the requirements of the application and the environment in which it will be used. Is a knob appropriate, or would a U-handle be better? What sort of U-handle?Below we review the "applied forces" that an application may require, and examine the best types of components for each motion.

1. Lift. You can use a knob for lifting if the force required is less than a pound, but typically U-handles are the best choice. Directly fighting the force of gravity generally requires a more heavy-duty handle, like a bridge handle (see here our EN 628 bridge handle), and you’ll definitely need to know the load capacity, to be sure it can hold up to the strain. Our online catalog includes load capacity for our U-handles.
2. Up-Down. This refers to the direction of motion applied, and differs from lift in that you are not lifting the entire weight of the apparatus. Because the force is significantly less, you could use a ball knob, push-pull knob, a U-handle, or a handle.
3. Left-Right. Obviously, 90 degrees off from #2 above, you can use similar components
4. Pull. Again, ball knobs, push-pull knobs, and U-handles all work. But when choosing the right one, take into account how much force will be used (for more force, use a U-handle), and consider the ergonomics involved (for two-finger pulling, use a knob that allows for grip, is comfortable, and is non-slip, like our GN 76 mushroom knobs).
5. Push. Use a ball knob or push-pull knob. If the application requires a larger knob, make sure it fits comfortably in the palm. If using a smaller knob, you may want to choose one with a concave surface to prevent the finger from slipping.
6. Push-pull. When both motions are significant, you may be looking at an application that requires more force, and therefore a larger component. Make sure the knob or U-handle is comfortable to operate and allows for a good grip.
7. Circular  To determine the best component for a circular motion, you must consider many aspects of the application. If you’re looking for fine, precise adjustments, a control knob is best. If you want a larger range of motion or are moving more mass, choose a crank handle or a handwheel. (Handwheels with digital indicators to measure the motion are an option, like the EN 953 series.) A control lever is another possible choice.
8. Circular for clamping. If the circular motion is being used to clamp or release, an adjustable (clamping) lever could be your best choice. We offer the unique torque-free component shown here, the GN 927 clamping lever with eccentrical cam. If you want to use a knob instead, a lobe or prong knob would be your best bet, as these allow for the grip required for turning. Handwheels are another option.
9. Rotate. Your options for rotating motion are many, and depend upon the torque and speed needed, as well as the space accommodations. In confined spaces, use a lever with a ratcheting feature or an adjustable lever. For low torque, use a knurled, lobe, T-handle, or prong knob. For higher torque, use a crank handle or handwheel. The latter is the best choice if speed is crucial.
10. Rotate-pull. The ideal choice for this is an adjustable lever, like our GN 300.4 zinc die-cast adjustable levers with secure clamping force.
11. Rotate-push. Any knob that provides a good rotational grip will work, such as a fluted, knurled, lobed or prong knob.
12. Multiple motions. A ball knob could work (knurling may be a boon), although a handle would offer more leverage. Choose fixed or rotating based on whether rotation will be required.

Keep in mind that many other factors come into play to determine the size, material, and design of your component choice. But basing your selection on the required applied force and motion is an essential way to begin. For further assistance, contact our Technical Sales Associates at 800-877-8351.