For effortless movement of your gantry system, using the correct casters is key. At Mine crane, we commonly quote three types of swivel casters: polyurethane, nylacron, and pneumatic. Each type of caster comes with its own pros and cons. How do you know which one is best for your system?
The materials that each caster is manufactured to function differently depending on the environment. The overall goal when using a Mine Gantry crane, as well as any overhead crane system, is to increase your workplace productivity in a sufficient manner. That is why using the proper casters for your specific application is important. Using the wrong type may result in greater force needed for movement, injury from straining, or loss of loads due to instability.
When choosing the correct casters, take these important factors into consideration:
loads
tread material/hardness
floor conditions
floor finishes
Ergonomics
Choosing the proper casters affects the ergonomics of your work facility. Pushing a gantry system rather than pulling is safer and more efficient. Pulling can increase the chances of injury due to the stretched and unsupported position of a worker's arm and back. The backward motion and the amount of force being exerted when pulling materials and machinery can result in getting run over by equipment. These dangers are amplified because pulling the system means you can't see where you're walking. Having the correct casters for your application will prevent unnecessary hardship by allowing for less force to be used.
Polyurethane Casters
Polyurethane casters are the low-maintenance option for your system. Constructed with little tread, this type of caster is most beneficial in an indoor application. Compared to pneumatics' rubber tread, polyurethane has a low rolling resistance, which allows the material to glide over smooth concrete surfaces with relative ease. The amount of force to initiate movement for a Mine Gantry that uses polyurethane casters is approximately five percent of the system's rated capacity, approximately two percent to continue moving, and approximately seven to 15 percent of the system's rated capacity to turn.
While the solidity of the casters makes for easy motion, if used on uneven terrain, the small wheel diameter and hardness of the tread would make your gantry system difficult to push over surface irregularities. However, the rated capacity for polyurethane can far exceed what a rubber tire can handle. Overall, polyurethane casters require little relative force for motion and have strong weight capacities, but can only be used on smooth, level surfaces.
Pneumatic Casters
Pneumatic tires are pressurized rubber tires with a flexible tread for shock absorption. These tires are the same type that would be used on your car, motorcycle, ATV, or other vehicles. Pneumatic tires fare better on pavement compared to polyurethane casters because the tread allows for a cushioned roll.
Pneumatic tires can either be foam-filled or air-filled. There are benefits to both options, but the choice will boil down to what is right for your application. Foam-filled tires are a sturdier alternative to air-filled tires that can deflate. When employing air-filled tires, you must monitor air pressure and be wary of punctures. While foam-filled tires are more durable, they are heavier and require more strength to push your system. Due to the solidity of the tire, foam-filled tires do not have the cushioned and smooth ride that air-filled tires provide.
A downfall when using both kinds of pneumatic tires is that they require more force to start motion. Due to the flexibility of the air-filled and foam-filled tire, it requires approximately 15-20 percent of the system's rated capacity to initiate and continue movement. It is also harder for the wheel to pivot, meaning more force is needed to turn your system. Additionally, the rated capacity is incumbent on the size of the wheel. Therefore, purchasing larger pneumatic tires for greater capacities is necessary, while nylacron or polyurethane casters can handle larger capacities.
When should you use a polyurethane, nylacron, or pneumatic caster? The answer lies in the use you need to get out of your Mine Gantry system. The force needed for these casters can sometimes be compared to pushing a skateboard and pushing a cart. The purpose of your system ultimately will enable you to determine which caster is necessary to achieve the motion you desire.
