Choosing Gas Strut Poundage Strength

[Capebuild]

Just installed the hatch and put a 2x4 under it to hold it up.... and put a scale on floor, 2x4 on top of it to get the "dead weight". The scale is showing 60#s. I was originally going to get 100# gas struts but now I'm thinking that might be overkill.
Is it "usual" to get struts a little over what the actual weight is... like maybe in my case 80#s might do well??

Any thoughts on what strength would be appropriate?

Thanks!

John

[GarthB]

Aside from the extra cost, I can’t imagine there being much of a disadvantage of going with the heavier struts. The additional 20# per side shouldn’t be a deal braking amount of additional fatigue induced on the hatch.

When periodically checking on our trailer in storage throughout the winter months, I noticed that the struts lost a significant amount of strength in sub-freezing temperatures. The 90# struts that I installed weren’t capable of holding the hatch open on their own. 100# may have been enough to do the trick. I never checked what our hatch weight was though.

[TimC]

John, have you checked out Dan Lott's calculator? It's here...

https://www.tnttt.com/viewtopic.php?t=58263

I did not have any luck mounting mine but that was a function of the idiot behind the hatch build and the strut mounting location and not the calculator. The calcs work for the majority of folks. For instance my brother's hatch and my son's hatch both work well. I went back to two wooden sticks. When I can't physically lift the hatch myself I'll look into it again.

[Capebuild]

Thanks for you thoughts, Garth and Tim.
I did look at the strut calculator a while back and ran my calculations off of it, in addition to just kind of diddling with the layout in the CAD.
I suppose I could get the 100# struts and see how they perform. I can always return them if they don't work well.... or if they work "overly well" and
the hatch just flies up uncontrollably. I suppose I'd have trouble closing it if that were the case.

Thanks again.

John

[JasenC]

I can say from experience, getting too heavy of a strut is going to put undo stress on your hatch and the attachment points seeing you will need to push on it all the harder to get it to close. It can also be hard to close a hatch that wide with even pressure on both struts, plus it might rise faster then you would like when opening.
You need to factor in strut length, weight and attachment locations.

The site I used to figure it out is no longer around, this may help. https://www.strutswest.com.au/how-to-calculate-the-gas-strut-length-and-force-required/