Sliding Hatch

[fallguy]

I need to build a sliding hatch and want to make it out of 1/2" acrylic so it is more open down below.
Walking on them possible, but not necessary and generally not done. Just don't want anyone falling through.

I also would like to make the companionway door under the hatch acrylic and opens out. I figure the top of the slide can be the stop and a small cover will act as a seal for the top of the door.

Dimensions of the door are about 24" high with a 20" width and the slide is going to be about 36" long and about 20" wide.

I need to come up with a leakproof profile for the slides.

I figure a garage is an absolute based on the long length. Length is needed as the drop into the hull is about 50"or so.

rwatson had a couple of nice pictures, but no profile details

I'd like to also make the slides of ptfe or Teflon.

 

[JamesG123]

Use UV resistant polycarbonate not acrylic (plexiglass). More expensive but it will last a lot longer, tougher, and easier to work with.

 

[fallguy]

I drew up a section.

Just not sure if the receiver and rail should be radiused ptfe or square. I could see where a radiused rail might be better and maybe leave the square guide.

I'm a little unsure about clearances for the moving parts.

 

[JamesG123]

Should not matter as long as they are not binding. They are self-lubricating. So mostly its a matter of how good are you at making a square. Oh and I guess the thermal expansion coefficient. Find out what that is for the teflon and whatever poly you use and there you go.

You will want to make the teak trim cover the entire receiver frame and screw into it. Otherwise it will look weird and you would see the ends of the screws in the clear poly.

 

[fallguy]

Should not matter as long as they are not binding. They are self-lubricating. So mostly its a matter of how good are you at making a square. Oh and I guess the thermal expansion coefficient. Find out what that is for the teflon and whatever poly you use and there you go.

You will want to make the teak trim cover the entire receiver frame and screw into it. Otherwise it will look weird and you would see the ends of the screws in the clear poly.

Good point.

I am also considering using linear bearings. They would roll nicer, maybe too nice?

 

[JamesG123]

Too nice. You would need a catch to keep the hatch from slamming back and forth in rollers. Plus they would eventually corrode/get clogged with gunk.