gas struts

[Corwin C]

The configuration of the struts will make just as much difference to the required strength of the struts as the weight of the hatch. Let me try to explain ...

Case #1: Just for simplicity's sake lets say the hatch weighs 50#. If the struts are vertical and in the center of the hatch (at the center of gravity), you would need (2) 25# struts just to "break even" to hold the hatch. The hinge would have very little force upon it (mostly just balancing the hatch on the struts.)

Case #2: Same hatch weight (50#). If the struts are vertical and halfway between the center of the hatch (again center of gravity) and the hinge, you will need (2) 50# struts just to "break even" to hold the hatch. In this case, the hatch and it's weight is using the strut as a fulcrum to "lift" on the hinge. The hinge will be (by the numbers) applying 50# of force to the hatch in the downward direction.

Case #3: Same hatch weight (50#). If the struts are vertical and halfway between the center of the hatch (again center of gravity) and the edge of the hatch away from the hinge, you will need (2) 17# struts (rounded up to the nearest pound) to hold the hatch. In this case, the hinge is helping to hold the hatch up and will be carrying about 17# of the hatch weight.

Now, if the strut is not vertical, it will be applying both a vertical and horizontal force at the same time. In all cases, your hinge will have to be strong enough to compensate for both the horizontal and vertical forces and the strut will have to be appropriately stronger to apply the additional force necessary to make up for the loss in the horizontal direction.

Also, the numbers that I have given will "just barely" support the hatch. It doesn't take into account wind, rain, anything hanging on the hatch (pop-ups, tarps), etc.

Everyone's situation will be different. If you don't have the exact same hatch weight and configuration, your strut strength requirements will be different. Also, as I hope that I've illustrated, the closer to the hinge that your struts are, the larger the forces involved. If anyone would like me to assist them in calculating these forces I would need to know the weight of the hatch and the horizontal distance that the center of gravity of the hatch is away from the hinge pivot point when fully open, the distance from the hinge pivot point to the strut support ends (both of them), the horizontal distance from the hinge point to the lower strut pivot point, and the length of the strut when the hatch is open.

Did we sufficiently muddy the water???

[GeoDrop]

Which auto parts store are people using to get struts? Do that have the brackets as well? If not, where are those sourced?

Gas struts are still an art to me. (Cause Andrew didn't turn all the strut information into a spreadsheet yet!)

I tried 90# struts, and they were too light. Then I went back to the auto parts store and exchanged them for 120# struts. They worked perfect.

Now you are probably wondering how heavy the hatch is. I don't know. I haven't taken it off to weigh it. Maybe Steve Fredrick knows? Steve?

Mike...

[emiller]

Which auto parts store are people using to get struts? Do that have the brackets as well? If not, where are those sourced?

Gas struts are still an art to me. (Cause Andrew didn't turn all the strut information into a spreadsheet yet!)

I tried 90# struts, and they were too light. Then I went back to the auto parts store and exchanged them for 120# struts. They worked perfect.

Now you are probably wondering how heavy the hatch is. I don't know. I haven't taken it off to weigh it. Maybe Steve Fredrick knows? Steve?

Mike...

McMaster c Carr is where you can find gas springs.

[GeoDrop]

Thanks.. I ordered them today with the associated hardware. I was afraid the auto parts stores would have the small pieces to attach it with.

Which auto parts store are people using to get struts? Do that have the brackets as well? If not, where are those sourced?

Gas struts are still an art to me. (Cause Andrew didn't turn all the strut information into a spreadsheet yet!)

I tried 90# struts, and they were too light. Then I went back to the auto parts store and exchanged them for 120# struts. They worked perfect.

Now you are probably wondering how heavy the hatch is. I don't know. I haven't taken it off to weigh it. Maybe Steve Fredrick knows? Steve?

Mike...

McMaster c Carr is where you can find gas springs.