Gas Strut Input Form
Formula Used
The calculator balances torque around the hinge. The lid creates a turning moment. The gas strut creates an opposite moment through its effective lever arm.
Weight force: W = mass × 9.80665, when weight is entered in kilograms.
Lid moment: M = W × Dcg.
Effective lever arm: L = Dmount × sin(angle).
Force per strut: F = ((M + friction) × allowance × safety factor) ÷ (number of struts × L).
Temperature correction: rating at 20°C = operating force ÷ temperature factor.
How To Use This Calculator
- Enter the lid or hatch weight.
- Select the correct weight unit.
- Measure the center of gravity distance from the hinge.
- Enter the proposed strut mount distance from the hinge.
- Enter the strut angle when the lid is held open.
- Add a safety factor and any extra hinge or seal moment.
- Press the calculate button.
- Use the recommended rating as a starting catalog size.
Example Data Table
| Example | Weight | CG Distance | Mount Distance | Angle | Struts | Use Case |
|---|---|---|---|---|---|---|
| Small cabinet lid | 12 kg | 300 mm | 160 mm | 40° | 2 | Storage box |
| Medium hatch | 25 kg | 450 mm | 220 mm | 35° | 2 | Workshop cover |
| Heavy access panel | 45 kg | 600 mm | 280 mm | 30° | 2 | Machine guard |
| Single side support | 18 kg | 380 mm | 210 mm | 42° | 1 | Narrow lid |
Gas Strut Planning Guide
A gas strut can make a heavy lid feel controlled. It can also protect hinges, hands, and nearby panels. The main task is simple. The strut must create enough turning moment around the hinge. That moment must balance the moment created by the lid weight. A good estimate starts with weight, center of gravity, mount distance, and strut angle.
Why Geometry Matters
Mount location changes the answer a lot. A strut mounted far from the hinge has more leverage. A strut working at a wide angle also has more effective leverage. When the angle is small, much of the force pushes along the lid. Less force helps lift it. That is why small angle errors can change the required rating.
Advanced Inputs
This calculator includes safety factor, temperature, friction, and allowance percentage. These fields help when a cabinet has tight seals, rough hinges, or outdoor use. Cold weather lowers gas pressure. Hot weather raises it. The tool converts the operating force into a suggested rating at the standard reference temperature.
Practical Selection Tips
Use two struts when the lid is wide or flexible. They reduce twisting and spread load into the frame. Use one strut only when the lid and hinge line are stiff enough. Always check compressed length before drilling brackets. The strut should not bottom out before the lid fully closes.
Mounting And Testing
Treat the output as a design estimate. Real brackets may bend. Hinges may add friction. Seals may need breakaway force. Test with temporary clamps before final drilling. Open and close the lid slowly. Watch for binding near both travel limits. Choose rated hardware that exceeds the calculated load.
Reading The Result
The force shown is the approximate rating each strut should deliver. The moment figures show the demand around the hinge. The lever arm shows how much of the strut position is useful. A larger lever arm reduces force. A smaller lever arm increases force. The suggested rating rounds upward. This gives a practical catalog value. It is still wise to compare nearby sizes. A slightly stronger strut may lift too fast. A weaker one may not hold safely. Final choice should match brackets, stroke, travel, and manufacturer guidance carefully.
FAQs
What does the gas strut force mean?
It is the approximate pushing force needed from each strut. The value helps you choose a catalog rating, usually listed in newtons.
Should I use one or two gas struts?
Two struts are better for wide lids. They reduce twisting and balance both sides. One strut can work on narrow, stiff panels.
Why does the strut angle matter?
The angle decides how much force becomes useful lifting force. A small angle reduces the effective lever arm and increases required strut force.
What safety factor should I enter?
Many basic estimates use 1.1 to 1.3. Use a higher value for heavy lids, uncertain weights, rough hinges, or outdoor installations.
Does temperature change gas strut force?
Yes. Lower temperature reduces gas pressure. Higher temperature increases it. This calculator applies a simple correction for planning purposes.
What is center of gravity distance?
It is the distance from the hinge to the balance point of the lid. For a uniform lid, it is often near the center.
Can I install a stronger strut?
A stronger strut may open too fast or strain brackets. Choose the nearest safe rating, then test the motion carefully before final use.
Is this result final for manufacturing?
No. Treat it as an estimate. Confirm geometry, bracket strength, stroke, compressed length, and supplier data before production or installation.