Cylinder Slams at the End? Cushioning and Speed Control Are Different
Cylinder travel speed and end cushioning solve different problems. If motion is acceptable through most of the stroke but impacts at the end, inspect the specified cushioning arrangement and load before changing general flow settings.
Adjustment and energy limits are cylinder-specific.
What is happening?
End cushioning manages energy near the end position. Designs include fixed, adjustable, and self-adjusting arrangements, each with limits. A cylinder can reach its end sensor while still imposing unacceptable mechanical impact.
Check these five things
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Identify the cylinder cushioning type and approved load-speed envelope.
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Observe where impact or rebound occurs using safe external evidence.
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Inspect mountings, alignment, and mechanical condition under isolation.
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Review adjustment procedures for the exact cushioning system.
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Validate any approved adjustment across intended payloads and both directions.
Worked example
A teaching actuator travels smoothly until its final section, then rebounds. Reducing overall speed removes the symptom but also changes cycle time. The engineering review must establish whether cushioning is incorrectly set, damaged, or inadequate for the actual energy.
Quick diagnostic reference
| Feature | Role |
|---|---|
| Flow control | Travel behavior |
| End cushioning | End-zone energy management |
| Mechanical stop | Defined load path |
| End sensor | Position indication |
The mistake to avoid
Do not keep tightening an adjustment without knowing its type and permitted range. Excessive restriction can prevent completion or create another pressure condition.
How to verify the fix
Confirm controlled arrival, acceptable settling, and correct end detection across the qualified range. Save the approved adjustment and load assumptions with the machine documentation.
Field-work boundary: These are educational diagnostic guides. Use the exact equipment manuals and approved site procedures. Electrical testing and machinery changes belong to qualified, authorized personnel; control hazardous energy and validate affected functions before release.
Technical reference
Festo: Cylinder cushioning methods. The examples and diagnostic tables above are original teaching material; they do not replace the product manual.