Slow down folded hatch that is quite heavy

[janerik12]

Gas springs are great for holding up and pushing up, but to dampen the descent? You might as well have mounted cords or nylon straps there.
You should be able to use these: 373.66.611-HE from the same company. Then you'll get a clear stop and brake function.
Just wondering why your gas springs don't stop the flap in the lowered position.

The only thing I can find about the braking force is the following:

Max. braking force 7.5 kg at flap height 70 cm and 2 flap fittings.
http://www.theofils.se/produkt/Luckbeslag-7001--22281.aspx

 

[janerik12]

I would interpret the second-to-last table to mean that with a 500mm hatch, you can let the hatch weigh 2.1 kg if you have the 12kg variant of the gas spring. So, a fifth of your hatch weight.

Then I need to find another gas spring that handles more weight.
Do you have any suggestions?

A gas spring from Jula can handle a maximum of 30kg, but maybe that's way too much, and you'll have to struggle to open the hatch?

 

[Liteavvarje]

Go there and try to pull it and compare it with the one you have, it shouldn't spring back but just ensure it doesn't snap, although it might be a bit stiff.

 

[fredrik.johansson]

Of course, you can try pulling, but it can't be too complicated mathematically to calculate the force needed in the shock absorber. It's been a long time since I calculated trigonometry, but if you look at Lesjöfors AB's website, there is a formula to calculate. Looking at your sketch, and assuming you can attach a stronger shock absorber in the same place as the other weak one, we get an angle of 51 degrees between the gas spring and the hatch. From that, we can calculate W in Lesjöfors' formula. If the hatch weighs 12 kg and its center of gravity is 250 mm from the edge (half the hatch width), and you have two shock absorbers, then the shock absorbers need to be a little over 400N + 10-15% margin, about 450-500N. (about 45-50kg) But I don't really know this kind of thing, so I would call Lesjöfors or someone else and ask for help. Swedol sells gas shock absorbers in different strengths.
http://www.lesjoforsab.com/gasfjadrar/kraftberakning.asp
http://www.swedol.se/gasfjadrar.html

 

[janerik12]

Tested Jula's 30kg gas spring. Couldn't press it in by hand so I think it will be hard to close the hatch with these

Contacted Lesjöfors and got a response that maybe an oil damper is what I should use instead of a gas spring. It will be a special order and expensive as hell about 500-600kr each. Not something I'm willing to do.

 

[nikek]

I'm going to mount a similar solution and I'm wondering what you, janerik, think? The store (Specialbeslag) recommends two 8kg gas springs. With your experiences, it feels like the panel will fall too quickly.

I have a cabinet with a door that opens down about 90 degrees.

The door weighs about 12 kg and right now you need to be careful when opening it.
You also have to brace it with your knee when it's fully open, otherwise it falls to the floor.

I have installed two gas springs [link] that are supposed to handle 12 kg per spring but they can't brake the door.

Are there any other gas springs you can recommend or something else I can try to fix this death trap