Choosing the right size gas struts for your camper trailer is crucial for safe, reliable, and effortless opening and closing of compartments, hatches, and the main camper lid. The ideal gas strut size depends primarily on the weight of the lid or component it’s supporting, the desired opening angle, and the mounting locations. While there’s no single “magic number,” understanding the calculations involved and factoring in real-world considerations will lead you to the perfect solution.
Understanding the Fundamentals of Gas Struts
Gas struts, also known as gas springs, are pneumatic devices that use compressed gas to provide controlled motion and support. They consist of a piston moving within a cylinder, with the gas pressure providing the lifting force. Choosing the correct strut involves understanding force (measured in Newtons, or N), length (both extended and compressed), and end fittings. A properly sized strut ensures the lid lifts smoothly, stays open without assistance, and doesn’t slam shut. Overpowered struts can make closing difficult, while underpowered struts won’t support the lid.
Calculating the Required Force
The core principle is balancing the weight of the lid with the force of the gas strut. While complex calculations involving trigonometry and leverage are ideal, a simplified approach can be effective for many camper trailer applications.
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Determine the Lid Weight: Accurately weigh the lid or component you want to support. Don’t guess! A bathroom scale can be useful.
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Calculate the Torque: Torque is the rotational force. To approximate this, multiply the weight by half the lid’s length (measured from the hinge line). This gives you an estimate of the torque acting on the hinge.
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Strut Placement and Angle: The closer the strut is to the hinge, the more force it will require. Ideally, the strut should be mounted at an angle close to 90 degrees to the lid when the lid is closed. This provides the most efficient force transfer.
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Conversion to Newtons: Convert your weight measurement to Newtons (1 kg = 9.81 N). This will allow you to directly compare to strut force ratings.
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Strut Force Estimation: Consider a safety factor. Add approximately 10-20% to your calculated force to account for friction, wear, and variations in manufacturing. This ensures the strut provides ample support. Use online gas strut calculators to refine this estimate, inputting your measurements for a more precise result.
Remember, these calculations provide an approximation. It’s crucial to test your setup and make adjustments as needed.
Length and Stroke Considerations
Besides force, the length of the gas strut is equally important. Two key measurements matter:
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Extended Length: The total length of the strut when fully extended. This determines the maximum opening angle of your lid.
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Stroke Length: The distance the piston travels within the cylinder. This, combined with the compressed length, dictates the minimum closed position of your lid.
To determine the required extended length, consider the desired opening angle of your lid and the distance between the hinge and the strut mounting point on the lid. A longer extended length will generally result in a wider opening angle. The stroke length must be sufficient to allow the lid to fully close.
End Fittings and Mounting Hardware
Gas struts come with various end fittings, such as ball sockets, eyes, and threaded ends. Choose fittings that are compatible with your mounting hardware and offer secure attachment. Ensure the mounting points on your trailer and lid are strong enough to withstand the forces exerted by the gas struts. Consider using reinforced brackets or plates for added security. Incorrectly installed struts can damage the trailer and pose a safety hazard.
Practical Tips for Choosing the Right Size
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Start with Research: Explore online forums and communities dedicated to camper trailers. Experienced builders and owners often share their gas strut specifications for similar applications.
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Consider Adjustability: Some gas struts are adjustable, allowing you to fine-tune the force after installation. This can be a valuable feature if you’re unsure about the exact force required.
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Test and Adjust: Once you’ve installed the struts, thoroughly test the opening and closing action. If the lid is too difficult to close, you may need to reduce the force. If it doesn’t stay open, you may need to increase it.
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Pair Your Struts: In most cases, you’ll use two gas struts for a lid. Ensure they have identical force ratings and are mounted symmetrically for balanced operation.
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Factor in Environmental Conditions: Temperature can affect gas strut performance. In colder weather, the gas pressure may decrease, reducing the lifting force. Consider this if you camp in varying climates.
Frequently Asked Questions (FAQs)
Here are some frequently asked questions to further clarify the process of choosing gas struts for your camper trailer:
FAQ 1: What happens if I choose a gas strut with too much force?
If the gas strut has too much force, the lid will be difficult to close and may even slam open with excessive force. This can damage the hinges, mounting points, or even injure someone. It’s always better to err on the side of slightly less force and then adjust if necessary.
FAQ 2: How can I measure the existing gas strut force if I’m replacing one?
If you’re replacing an existing gas strut, look for a force rating printed on the strut’s cylinder. This is usually expressed in Newtons (N). If the rating is not visible, you can try weighing the lid and calculating the required force as described earlier.
FAQ 3: Can I adjust the gas pressure in a gas strut?
Some gas struts are adjustable, typically by using a valve to release some of the compressed gas. However, most standard gas struts are not adjustable. If you need adjustability, specifically look for adjustable models.
FAQ 4: What are the common causes of gas strut failure?
Common causes of gas strut failure include wear and tear, corrosion, damage to the piston rod, and loss of gas pressure due to seal failure. Regular inspection and lubrication can help extend the lifespan of your gas struts.
FAQ 5: Where can I buy gas struts for my camper trailer?
Gas struts are available from various sources, including automotive parts stores, hardware stores, online retailers specializing in RV and trailer components, and directly from gas strut manufacturers.
FAQ 6: Are there different types of gas struts for different applications?
Yes, there are different types of gas struts designed for various applications. These include standard compression struts, tension struts (which pull instead of push), and locking struts (which can be locked in a specific position). For camper trailers, compression struts are most commonly used.
FAQ 7: How do I install gas struts correctly?
Correct installation is crucial for the safe and effective operation of gas struts. Follow the manufacturer’s instructions carefully. Ensure the mounting points are strong and secure. Use appropriate hardware and tools. If you’re unsure, consult a professional.
FAQ 8: Can I use one gas strut instead of two?
While it’s possible to use one gas strut, it’s generally not recommended for larger lids. Using two struts provides better stability and distributes the load more evenly, preventing warping or damage to the lid.
FAQ 9: How do I maintain gas struts to extend their lifespan?
Regularly inspect the gas struts for signs of damage or corrosion. Wipe them clean with a damp cloth and lubricate the piston rod with a light oil or silicone lubricant. Avoid exposing them to harsh chemicals or extreme temperatures.
FAQ 10: What is the difference between progressive and non-progressive gas struts?
Progressive gas struts offer increasing resistance as they extend, providing a smoother opening and closing action. Non-progressive struts offer a more consistent force throughout their stroke. The choice depends on personal preference and the specific application. Progressive struts are generally preferred for heavier lids.
FAQ 11: How do I determine the correct mounting location for gas struts?
The ideal mounting location depends on the lid’s weight, size, and desired opening angle. Experiment with different positions to find the sweet spot where the strut provides optimal support and smooth operation. Online gas strut calculators can also help determine the best mounting location.
FAQ 12: Are there any safety precautions I should take when working with gas struts?
Always wear safety glasses when working with gas struts. Avoid disassembling or attempting to repair gas struts, as they contain high-pressure gas. If a gas strut is damaged or leaking, replace it immediately.
By carefully considering these factors and utilizing the provided information, you can confidently select the perfect gas strut size for your camper trailer, ensuring years of reliable and effortless operation.