Conveyor Tips

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Here are some basic rules of thumb that should be considered when planning gravity conveyor applications.

1. A Minimum of three (3) rollers must be under the load at all times (minimum of seven (7) wheels with skatewheel conveyor) provided that. . .
   
1. The underside of the object to be conveyed is smooth, rigid, and uniform.
2. The load weight is evely distributed over the contact surface of the material to be conveyed.
2. Roller capacity should be calculated based upon the assumption that only two thirds (2/3) of the rollers under the load will actually carry the weight. This is due to irregularities in unit load undersurface.
3. Most manufacturers chart roller capacities with the assumption that the load is placed on the conveyor without impact. Dynamic loading (ie: cases thrown onto conveyor) may require roller centers to be closer together to distribute shock more efficiently. In areas in which impact loading is expected, we highly recommend increasing roller wall thickness, bearing size, capacity, and frame weight as an added precaution.
4. Tapered roller curves are more highly recommended than straight roller curves because they provide the best tracking and least skew.
5. Determining the pitch (angle of incline) of gravity conveyor is difficult by the use of charts and graphs. Rather, it is a combination of experience and established principles that will aid in forecasting the required grade. Lab testing is highly recommended to insure the desired performance. The following information is crucial to making such a deterimination:
1. Weight of load.
2. Character of composition of carrying surface.
3. Length of roller and number of rollers under load.
4. Length of run.
5. Type of roller bearing.
6. Is load static or dynamic at start of run?
7. As a 'rule of thumb', the following guidelines are a good place to start:
• Gravity Roller Conveyor -- 6" loss of elevation over a 10' run.
• Gravity Skatewheel Conveyor -- 4-5" loss of elevation over a 10' run.

Although gravity conveyor systems seem simple at first glance, most applications require a great deal of planning to actually accomplish the intended goals. The aforementioned principles are only cursory guide-lines and professional guidance should be sought when planning new systems or adding to existing equipment.