Suggestions on my woody teardrop design?

[Slaskman]

Made my self a convertor in a excelfile and now all is clear

[_Ryan_]

The build has begun! You can follow my Build Journal here:

http://www.tnttt.com/viewtopic.php?f=50&t=53842

[KCStudly]

Have to agree, very nice design illustrations!

My thought on the hatch is that a lot of people have hell trying to keep them from warping when applying the skins and that this usually happens when using only 1-1/2 inch deep ribs. On a long curvy hatch like yours I just don't think 1-1/2 deep ribs are enough. My solution, although not finished building yet, was to make deeper 3 inch ribs, only 4 of them, and to make sure that I left enough clearance between the finished trimmed out edge of the galley counter and the inner surface of the ribs (my ribs will be exposed on the underside, with inner skin on top + foam + outer canvas/painted skin...Foamie style hybrid).

The resistance to bending is a quadruple function relative to depth of section (inserting my moment of inertia 4th power outer fiber rant here).

Copied from my own post in Stacie Tamaki's thread,

Remember this, regardless of weight, the further apart the outer "fibers" of a given part are the stronger that part will be exponentially, so the 2 inch tube might weigh a little more than the 1 inch, but it will be much more than twice as strong over the same span (look up moment of inertia).

Oh heck, here's a snippet from wiki, "The moment of inertia of an object about a given axis describes how difficult it is to change its angular motion about that axis. Therefore, it encompasses not just how much mass the object has overall, but how far each bit of mass is from the axis. The further out the object's mass is, the more rotational inertia the object has, and the more rotational force (torque, the force multiplied by its distance from the axis of rotation) is required to change its rotation rate."

In other words, structural members that have the mass further away from the center axis will always be stronger in bending than a member with the same mass located closer to the load axis. That's why tubing is stronger for its weight than bar that weighs the same; the mass is further out from the center axis.

You don't have to change the upper cabinet face or top location just for the struts; if you want you could build in pockets or nooks at the edges of the cabinets for the struts to retract into (... do make clearance for deeper hatch ribs, tho).

Looks great so far. I'll be following along on this one.

[nevadatear]

Fyi, our cabinets go all the wall to the ceiling on the galley and struts, pneumatic, work just fine. Maybe the are placed lower?, but they fold doehwards.

[_Ryan_]

I've been thinking about the struts and had been leaning towards altering my upper galley cabinets to accept them. However recently I was thinking I could recess them inside the outer ribs of the hatch itself. I don't know if this idea has been tried before (perhaps because it wouldn't work well), but it might turn out nicely.

[WhitneyK]

WOW!!!

Nice set of plans. How hard would it be to make them to a, mmmm, say, 10' total length?
Those are going to be excellent to build from.

[_Ryan_]

WOW!!!

Nice set of plans. How hard would it be to make them to a, mmmm, say, 10' total length?
Those are going to be excellent to build from.

Thanks! If you have a bit of knowledge of SketchUp then it wouldn't take too long. I will post my final SketchUp model in a few weeks once I get the last details ironed out.

[Shadow Catcher]

My suggestions are more the mechanics, consider using computer case fans in place of the Fantastic fan, I use two Antec three speed case fans.

Include more outlet/plugs than you think you need

[wyldesyde007]

Great looking design! I noticed that you mentioned that you are using the northern tool 5x8 trailer, I too am looking to start my build on that trailer. When you get the chance (I know you will busy building) would you mind sharing the physical dimensions of the trailer? The info I have found thus far on it is a bit spotty and I would like to have them correct when I start drawing in sketch up! TIA

[_Ryan_]

Great looking design! I noticed that you mentioned that you are using the northern tool 5x8 trailer, I too am looking to start my build on that trailer. When you get the chance (I know you will busy building) would you mind sharing the physical dimensions of the trailer? The info I have found thus far on it is a bit spotty and I would like to have them correct when I start drawing in sketch up! TIA

I'll do you one better, I have attached the Northern Tool 5x8 SketchUp model I designed for my build. It has the correct width, length, frame/cross member thickness, tounge dimentions, axle location, frame height, cross member width and locations. There are a couple of things that are not correct but they are mostly cosmetic like the wheel style, but the wheel diameter is correct. I will post this to the SketchUp model section when I get the time. Enjoy!

P.S. If you have any specific dimension concerns you can open the model in SketchUp and use the measuring tool.

UPDATE: I created a thread here: http://www.tnttt.com/viewtopic.php?f=62&t=54234 in the SketchUp section with an updated model. Trying to keep everything up-to-date

[DMcCam]

Hi Ryan, Your layout is very good and almost exactly what I did. Other than the areas already mentioned, you might consider rounding the inside corners of your skeletonized walls. An engineer buddy of mine said that it makes the corners much more structural and likely not to fail.


Here's an example of what I'm on about.

All the Best,

Dave

[wyldesyde007]

Hi Ryan, Your layout is very good and almost exactly what I did. Other than the areas already mentioned, you might consider rounding the inside corners of your skeletonized walls. An engineer buddy of mine said that it makes the corners much more structural and likely not to fail.


Here's an example of what I'm on about.

All the Best,

Dave

Wise counsel, this would definitely strengthen the ribbing although you do regain some lost strength with the sheathing.

[_Ryan_]

Hi Ryan, Your layout is very good and almost exactly what I did. Other than the areas already mentioned, you might consider rounding the inside corners of your skeletonized walls. An engineer buddy of mine said that it makes the corners much more structural and likely not to fail.


Here's an example of what I'm on about.

All the Best,

Dave

Hi Dave!

Haha, there is a reason it looks similar as I have spent an embarrassing large amount of time on your build thread and "borrowed" many of your great ideas for my own design. You provided lots of great information and many pictures which clarified many aspects of the build which I had questions about. I am trying to show the same amount of detail on my build thread to help others in a similar way.

I appreciate your comments and I think you have a good idea. I just finished splicing the walls and completed the wall templates that I will using to cut the walls with a router. I will add this before completing the walls this upcoming weekend.

Thanks again!

Ryan

[_Ryan_]

I decided to add some more pictures to the first post in this thread now that I have all but completed my designs and am well into my build. There are now a few more interesting things to see, and in color!

One of the things I added is the 12" x 40" picture window I found on ebay, which you can see it in the pictures below. I am planning on installing it above eye level so we can look at the stars while laying down. The roof is nearly flat at this section so I think that I can make it work. The one thing I am concerned about is the window comes with weep holes and with my installation I will probably have to plug those with silicone.





Besides that I have finalized the cabinet deigns, found the okume plywood for the outer skins which I have decided to dye a red mohagany, and moved the door a bit farther back. There are a few more pics in my design gallery if you are interested.

Cheers,
Ryan

[KCStudly]

Nice modeling work.

At first I was concerned that your cabinet door handles might hit on your side walls, what with the apparent side opening doors and bail style pulls, but it looks like you have left a wide jamb on that side of the cabinets. Well thought out.

You do very nice work.