Top Hatch Help Request

[WolfeDen]

I read the recent posts on gas struts for the rear hatch and found it helpful for that configuration. Thanks to all that posted as it will come in handy when I am working on that part.

In one of my (frequent) hare-brained schemes, I have decided to nix the trolley top on my build. Instead, I have built a hatch that is 25x40. My idea is to have the hatch raise straight up on gas struts. I plan to fabricate a screen and window system that will attach when raised and detach for travel/storage.

Here are my questions to answer before I proceed further.

Would gas struts be feasible? How many and where would you place struts? If not how would you support the hatch when open?

How would you latch it down for storage/transport?

Thanks for the input/ideas/criticisms in advance.

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[greygoos]

If you havent done so already do a search at the top of the page. there are plenty of "pop top" ideas , suggestions and actual builds.

[Aguyfromohio]

Gas struts would probably work but I personally would not make them my first choice. I notice gas struts on hinged doors and hatches all over the place - boats, cars, rv’s.... but not on straight lift tables and such with four corners that move together. I never thought about it much but there is probably a good reason it’s rarely done that way.

If your hatch is light and only travelers a couple feet you may not need any force assist, just sliders of some sort and a clever latch, maybe slider hardware intended for the drawers on cabinets.

[WolfeDen]

If you havent done so already do a search at the top of the page. there are plenty of "pop top" ideas , suggestions and actual builds.

I did several searches over a few hours and did not find anything that fit the bill.

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[WolfeDen]

If your hatch is light and only travelers a couple feet you may not need any force assist, just sliders of some sort and a clever latch, maybe slider hardware intended for the drawers on cabinets.

The idea for struts was certainly not for force assist. Just a way to keep the hatch up without hinges. Can't picture how drawer slides would work, unless they are allowed to pivot at the attachment points.

I am hoping for at least a foot of travel, maybe 18 inches tops.


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[WolfeDen]

If your hatch is light and only travelers a couple feet you may not need any force assist, just sliders of some sort and a clever latch, maybe slider hardware intended for the drawers on cabinets.

The idea for struts was certainly not for force assist. Just a way to keep the hatch up without hinges. Can't picture how drawer slides would work, unless they are allowed to pivot at the attachment points.

I am hoping for at least a foot of travel, maybe 18 inches tops.


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[Aguyfromohio]

If your hatch is light and only travelers a couple feet you may not need any force assist, just sliders of some sort and a clever latch, maybe slider hardware intended for the drawers on cabinets.

The idea for struts was certainly not for force assist. Just a way to keep the hatch up without hinges. Can't picture how drawer slides would work, unless they are allowed to pivot at the attachment points.

I am hoping for at least a foot of travel, maybe 18 inches tops.


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Oh, right, that’s obvious with a bit of thought, my bad. Maybe a scissors frame on two sides, as simple as a pair of oak slats with a center pin on each side? Simple catch or latch to lock it fully up

[WolfeDen]

Sent from my SM-A520W using Tapatalk[/quote]

Oh, right, that’s obvious with a bit of thought, my bad. Maybe a scissors frame on two sides, as simple as a pair of oak slats with a center pin on each side? Simple catch or latch to lock it fully up[/quote]

I like the idea of scissoring slats. Thanks!


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[greygoos]

Have you tried looking at the Compact in the design library? I am sure you could adapt something similar to your build.

[tony.latham]

If your hatch is light and only travelers a couple feet you may not need any force assist, just sliders of some sort and a clever latch, maybe slider hardware intended for the drawers on cabinets.

The idea for struts was certainly not for force assist. Just a way to keep the hatch up without hinges. Can't picture how drawer slides would work, unless they are allowed to pivot at the attachment points.

I am hoping for at least a foot of travel, maybe 18 inches tops.


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Obviously, you'll still need a hinge, right? Or perhaps I don't understand your design.

However you decide to keep your hatch open, remember that you need something to keep it from getting blown off. There are members here that have had that happen.

My idea is to have the hatch raise straight up on gas struts.

I installed gas struts on our crawl-space access door in our home. The 60-pound door is vertical when open. The Excel program suggested two 150-pound struts.

What worked were two 50-pounders since it takes no pressure to hold a door (or hatch) vertically. It's much different to hold a door at 45º vs. 90º.

Anybody that doesn't get a near headache on figuring struts is a genius. So hang in there.

Tony

[WolfeDen]

If your hatch is light and only travelers a couple feet you may not need any force assist, just sliders of some sort and a clever latch, maybe slider hardware intended for the drawers on cabinets.

The idea for struts was certainly not for force assist. Just a way to keep the hatch up without hinges. Can't picture how drawer slides would work, unless they are allowed to pivot at the attachment points.

I am hoping for at least a foot of travel, maybe 18 inches tops.


Sent from my SM-A520W using Tapatalk

Obviously, you'll still need a hinge, right? Or perhaps I don't understand your design.

However you decide to keep your hatch open, remember that you need something to keep it from getting blown off. There are members here that have had that happen.

My idea is to have the hatch raise straight up on gas struts.

I installed gas struts on our crawl-space access door in our home. The 60-pound door is vertical when open. The Excel program suggested two 150-pound struts.

What worked were two 50-pounders since it takes no pressure to hold a door (or hatch) vertically. It's much different to hold a door at 45º vs. 90º.

Anybody that doesn't get a near headache on figuring struts is a genius. So hang in there.

Tony

Hi Tony - The idea is to have the whole hatch rise like an elevator. The current iteration of the plan is to velcro clear plexiglass and screens for light and ventilation. Given the light weight of the 3/8 ply and 1x2 framing, some pretty lightweight struts would work. Just not sure where to place them and how many to ensure stability. Also we live on bald prairie that experiences frequent high winds, so it has to be sturdy.

[WolfeDen]

Have you tried looking at the Compact in the design library? I am sure you could adapt something similar to your build.

I have seen that one and it was the original basis for my hare-brained scheme. My version includes the hatch rising vertically like an elevator and not hinged on one side. I think going with wood scissor like supports near each corner is the simplest and sturdiest method.

[Aguyfromohio]

Hi Tony - The idea is to have the whole hatch rise like an elevator. The current iteration of the plan is to velcro clear plexiglass and screens for light and ventilation. Given the light weight of the 3/8 ply and 1x2 framing, some pretty lightweight struts would work. Just not sure where to place them and how many to ensure stability. Also we live on bald prairie that experiences frequent high winds, so it has to be sturdy.

Very nice. The hard plexiglass window panels should be strong enough hold up the lightweight hatch after you place them. How do you see the struts looking when the hatch is closed?

By definition a gas strut can only close to not-quite-half the extended length. A typical 18 inch extended strut is 10.5 inches long when closed. Do you envision the gas struts hanging straight down into the cabin when the hatch is closed, or somehow tucked away off to the side...maybe your hatch is the full width of the coach and the struts can be tight against the walls out of the way...?

[WolfeDen]

[/quote]

Very nice. The hard plexiglass window panels should be strong enough hold up the lightweight hatch after you place them. How do you see the struts looking when the hatch is closed?

By definition a gas strut can only close to not-quite-half the extended length. A typical 18 inch extended strut is 10.5 inches long when closed. Do you envision the gas struts hanging straight down into the cabin when the hatch is closed, or somehow tucked away off to the side...maybe your hatch is the full width of the coach and the struts can be tight against the walls out of the way...?[/quote]

The hatch is 25x40 inches, with the long side front to rear. The roof is comprised of 3/8 ply, 1.5 inch foam and 1/8 ply. The hole in the roof is lined with 1x4 that extends up from the roof. After PMF, water will have to travel up and through weather stripping on the top of the 1x4 to penetrate. The hatch has a 1x2 perimeter that over laps the 1x4. I was hoping the struts would attach to the 1x4 and then the hatch. When closed the struts would be near horizontal and near vertical when opened. Attached is a (admittedly crappy) pic showing the 1x4 a d the hatch lifted from one end.

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[WolfeDen]

A non technical friend of mine suggested storm door closer with the touch and close option. After a bit of consideration I dismissed this idea. A good wind might close them while I sleep (heavily) and carbon dioxide takes over from there. Maybe just my paranoia, but better safe than dead. Also I think I have enough brain damage for now.

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