Stroke Alert Basic Troubleshooting
Check for material buildup on conveying surfaces inside the pan (pan bottom, flat decks, screens, and below the screens in the sub-pan). If equipped with a flexible sub-pan liner, check for tears and material buildup under the liner.
Inspect the conveyor for broken, loose, or missing reaction springs.
Are all rocker arm bushings in good condition? Are the bushing bolts tight?
Verify the eccentric shaft operating speed matches the design RPM.
Have any modifications been made to the pan or balancer? Has any weight been added or removed?
If parts have been replaced, are they the correct components and do the part numbers match what is shown on the General Arrangement drawing machinery list?
Natural Frequency
Vibratory equipment requires the right balance between weight, speed, and spring rate.
Understanding Weight, Speed, & Configuration
Changes to equipment weight, operating speed, or machine configuration can significantly affect operating stroke and overall performance. Explore these topics to learn about common causes, potential impacts, and recommended troubleshooting steps.
Change in Weight
Material buildup on conveying surfaces — particularly wet or sticky “fines” — can increase the weight of the pan and result in Overstroke. In some applications, sticky material may also accumulate on the inside of the pan, further increasing the shaking weight of the equipment.
To maintain the recommended operating stroke, inspect and clean conveying surfaces regularly. Adjust your cleaning schedule to suit your operating conditions and prevent excessive material buildup.
Consult with ACTION about installing an SCU (Stroke Control Unit) to control stroke between cleanings.
See the Change in Configuration tab for additional information.
Change in Speed
Understanding RPM
Vibratory equipment that uses reaction springs (natural frequency design) is engineered to operate at a specific eccentric shaft or vibratory motor RPM. Even a small change in operating speed can significantly affect the operating stroke. On natural frequency equipment, a variation of as little as 10 RPM may be enough to impact performance.
For additional help with change in speed, see RPM Alert Troubleshooting page.
Change in Configuration
Modifying the equipment can change its operating stroke by altering the machine’s weight or spring characteristics. Adding extensions, liners, skirting, highsides, diverters, heavier screens, or other components increases the operating weight and may result in overstroke. Likewise, removing structural components reduces the operating weight and can affect performance. Always consult ACTION before making mechanical modifications.
When replacing springs, always use the specified part number. Springs from another manufacturer—or those that simply fit—may have different spring rates, even if they appear identical. Changes in spring rate alter the natural frequency of the machine and affect the relationship between speed, weight, and operating stroke. Increasing the total spring rate reduces stroke, while decreasing it increases stroke.
If you are unsure whether a modification or replacement component will affect machine performance, consult ACTION at (503) 537-1111 before proceeding.
