Figuring Hatch Props?

[Steve Frederick]

Any ideas or formula for figuring out the weight rating for Gas props?
I'm going to have a 80" wide by about 5' hatch. I'll do my usual framing, 1/8" ply in, and (2)-1/8"ply layers outside.
Also, while I'm asking, how to figure the length?

Thanx!

[halfdome, Danny]

Steve, I know there are charts out there on the subject, but to me it's like taking a shot in the dark with hopes you'll hit the target. I would go with the heaviest pound rating available with the shortest stroke. Danny

[emiller]

http://www.mcmaster.com/
page 1137 or type in gas struts on the McMaster Carr web site. I used 120 # on my first tear and 150 # on my fourth tear. And I would recamend buying ends that are steel not plastic, those struts at that poundage are too tuff for plastic ends.

[sdtripper2]

Steve F~


Help with quote for the Formula for Gas shocks page here:
http://www.easyliftsprings.com/contact/ ... urown.html

Here is the thread that holds Steve T's (sonetpro) formula
for struts formula for gas struts please read:
http://tnttt.com/viewtopic.php?p=121099

[Leon]

I figured about where the spring would have to attach due to available stroke, then I opened the hatch and put a stick from that point to a scale on the floor of the teardrop. That weight was the weight of the hatch at that point. A longer stroke spring will allow you to move the mounting away from the hinge, therefore because of leverage, it will weigh less at that point. I then divided by 2 (used 2 springs) and bought the next heavier spring. If I figured 30 pounds, and they are available in 20 and 40, I got the 40s.