Gas struts coming undone

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Re: Gas struts coming undone

Postby Sheddie » Fri Nov 21, 2014 3:28 pm

Hi Olive,
I see that you are quite new to the site.
Where are our manners? :o
Welcome :shake hands:
How about a "newbie" report and let us know, who and where, and what your camper is, and :pictures: :pictures:
:beer: Frank
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Re: Gas struts coming undone

Postby KCStudly » Fri Nov 21, 2014 3:53 pm

So the thing is that you can't just look at where the strut is when it is closed. As we have been beating about the bush trying to say, often times the struts are configured to pass thru the shortest length as the hatch approaches closed, then extend slightly when fully closed. By having the strut "go over center" there is a slight amount of push trying to keep the hatch closed. This is why it is important to not try to have the strut be fully compressed in the closed position.

If there is enough free play or extra shaft to fit a zip tie, as angib suggested, this is a great way to see how far the strut goes toward compressed despite where it is when fully closed. the camera on a timed shutter will tell you where it is when fully closed. I'm betting that the answer lies within these two bits of info.

And yes, where are our manners? Welcome to the forum! :thumbsup:
KC
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Re: Gas struts coming undone

Postby migal0412 » Fri Nov 21, 2014 4:31 pm

I have been thinking about this problem again overnight but without actually seeing the strut set up in this particular case it’s hard to tell although I tend to think that the compressed strut length may not be the problem if my arc method of checking shows the bottom bracket aligned on the arc.

There are lots videos and diagrams along with various formulas and ideas available on the net for fitting struts which often can and does confuse the likes of me. So with this in mind and to possibly add to the confusion here’s my method of fitting struts which works for me.

1. Place a temporary prop under the hatch where you want it to be when fully opened
2. Measure the total length of the hatch cover from the hinge out
3. Measure one quarter of that distance (out from the hinge) and then place 3 pencil marks, 1 dead centre and 1 on each side
4. Get your bathroom scales and place them under the temporary prop in the centre. Don’t forget to allow for the weight of the prop. Note the weight as this will be the total weight your struts need to lift. Note that this weight will be different to the total unhinged weight of the hatch.
5. Go buy your struts. Remember each strut will be lifting half the weight you have recorded. As far as length of the strut is concerned I really don’t think it is critical but I reckon the longer the better.
6. Fix your top brackets on the pencil marks you made each side carefully lining up the ball with the pencil mark.
7. Let the struts hang freely and then describe the arc they make as they swing on the side wall with your pencil, again try to line up the centre of the cup where the ball goes.
8. Fix your bottom bracket and then the struts
9. Finally remove the prop and hey presto they should work.

NOTE:
While this opinion is free, it has been mathematically determined to be worth at least twice that amount. :)
Cheers Mike
Being so bloody good-looking does not automatically make me the expert on anything.
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Re: Gas struts coming undone

Postby Sheddie » Fri Nov 21, 2014 8:51 pm

KCStudly wrote:So the thing is that you can't just look at where the strut is when it is closed. As we have been beating about the bush trying to say, often times the struts are configured to pass thru the shortest length as the hatch approaches closed, then extend slightly when fully closed. By having the strut "go over center" there is a slight amount of push trying to keep the hatch closed. This is why it is important to not try to have the strut be fully compressed in the closed position.

If there is enough free play or extra shaft to fit a zip tie, as angib suggested, this is a great way to see how far the strut goes toward compressed despite where it is when fully closed. the camera on a timed shutter will tell you where it is when fully closed. I'm betting that the answer lies within these two bits of info.

And yes, where are our manners? Welcome to the forum! :thumbsup:

KC has the idea. If you want to know if it goes over centre, take a straight line from the hinge to the bottom mount. If the top mount passes this line when the hatch is shut it has gone over centre. Otherwise as he said.
:beer: Frank
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Re: Gas struts coming undone

Postby olive » Sat Nov 22, 2014 9:25 pm

Image

Got the new hefty made eyelet strut ends and mounts installed. The struts aren't about to fall off these mounts.

The new mounts' screw holes of course didn't align with the old mounts' screw holes so had to fuss. After some trial repositioning, the struts assist in opening the hatch, hold the hatch open and - after testing with the zip tie technique - do not over compress. I'm not so certain this ends my strut issue. I'm guessing the day will come when I want the hatch to open further and I'll need to invest in some longer struts...but not today.

My thanks to all who provided valuable advice.
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