Lexan-Aluminum roof hatch

[tribologist]

The roof hatch has finally happened! I bent the front and rear tube last fall but it was to late to finish it so i put some effort in last few weeks after I figured how to use the 3D printer to prototype hinges. Final stuff came together after scrounging in a second hand boat part place in Mystic where i found the gas spring brackets and the screw down locks. The L shape gas spring brackets were saw cut and bent to double as holds for tge screw down locks. I still need to install the seal but the flex of the lexan make it seal up good. When I bought the boat the plate had a wood piece on each side and it was tied down. The CAD geometry is available in onshape as public domain. The key is to use garbage Home Depot aluminum for the front and rear. I tried bending 6061 and it would require a roller. I just bent them by hand. I had them about a ft to long on each side. Same for the side tubes. They are twisted before cut to length Using a vice and big-a... wrench

[DesertAlbin736]

Nice work! That looks very much like the one our boat had when we bought it. The only differences were that ours didn't have a good reinforcing frame like yours & nice hinges (which are similar to what I used on my teak hatches), and had spring props instead of gas shock types to hold it open. If you decide to do any over the road trailering/transporting be extra sure to tie it down good. You'd be surprised how much force a 55 to 65 mph slipstream can exert if that wind gets under it & could bend those frames like pretzels. Your frame looks pretty sturdy & appears you didn't have trouble with clearing the stub mast on opening like mine did. Ours was much more flimsy. Did you have to change the rake angle of the mast to have it clear? If possible I'd suggest adding a couple more closing hatch dogs, at least two or possibly three across the front. I found with ours it was tough to make it watertight when closed.

0306141616.jpg

[tribologist]

Thanks DA. I actually had to run the band saw on the back of the mast to get it to clear. I actually rode in the boat once on the highway with the lexan plate and its was really lifting. The old arrangement had strings tying down the corners and the front center. The screw down gives a pretty secure lock but i also have holes for tiedowns. Im thinking of making some webbing straps with cam lock buckles. The tubes takes quite some force to bend and then the mast secures the center part so its probably fine as is. I got up to 70mph today so do far so good... Based on the image you posted it does not look like it had much of a frame.

I have a seal waiting to be installed. Its the kind you push over the edge and it has a perfect 3/4” D bulb on one side. I need to cut about 1/4” from the mast foot to make it clear

[DesertAlbin736]

I suppose you could cut the angle of the mast at the base so it had less rake & more vertical? Either way. I like that you can raise the top higher than we could with the spring props on our old top.

For our opening hatches I used this type of prop rods which gives you a range of adjustment. Each of my teak hatches have two hatch dogs. Which reminds me, I'd suggest adding locking nuts to your hatch dogs which are the same type we have (as can be seen here), because without them they WILL work loose when jouncing over the road on longer trips. Have you notices the looseness of the threads? Of course you may or may not be trailering thousands of miles like we do. Or am I mistaken, are those lock nuts on the spindles? If so, good man!

DSCN2021crop.jpg

[tribologist]

Lol. They sure are. Im thinking of making a ratchet lock that prevent them from working themself loose or something else that provide that function. I actually think the mast will provide secondary retention but i have to much work in it to take any chances. I was looking for that style supports but i had two gas springs from this years FIRST robot so I tried them. I made the C-C so i can put in 10.8” to 17.8” long ones but these are little shorter. Gas springs are actually cheaper than the boat hatch rods. $19 ea at mcmaster. Its also much easier to manage that big hatch with springs. I will do a youtube video.

[motthediesel]

Did you weld those offset hinges? That looks like a nice bead. I’m pretty good with steel, but not so good with aluminum.

[tribologist]

Did you weld those offset hinges? That looks like a nice bead. I’m pretty good with steel, but not so good with aluminum.

Thanks. Its actually stainless. Easier than steel. Very forgiving unless you get it inspected..,, I took two different sea-dog hinges and combined them. The extensions came from a strap hinge. Made a little fixture in the 3-D printer to align the pieces. TIG on stainless is quite easy. I got a Miller Diversion TIG a few years ago to support my robotics team with welding. Im still learning. Aluminum is hard. Whats nice is no mess and splatter

[tribologist]

Nice work! That looks very much like the one our boat had when we bought it. The only differences were that ours didn't have a good reinforcing frame like yours & nice hinges (which are similar to what I used on my teak hatches), and had spring props instead of gas shock types to hold it open. If you decide to do any over the road trailering/transporting be extra sure to tie it down good. You'd be surprised how much force a 55 to 65 mph slipstream can exert if that wind gets under it & could bend those frames like pretzels. Your frame looks pretty sturdy & appears you didn't have trouble with clearing the stub mast on opening like mine did. Ours was much more flimsy. Did you have to change the rake angle of the mast to have it clear? If possible I'd suggest adding a couple more closing hatch dogs, at least two or possibly three across the front. I found with ours it was tough to make it watertight when closed.

0306141616.jpg

I seen that image before but now I looked closer and there are the strangest boats in the background. Houseboats?