Hi yet again:
I thought you guys might be interested in how I came up with the curved back end. This was relatively easy given that they are a perfect circle and this made it much easier than you might think.
When I first got started with this curved top I admit I was somewhat perplexed on how to go about it . . . Ok even a bit overwhelmed. For any of you wanting to take on these 3 dimensional shapes I will share a secret. Don't try and tackle all three Axis at once. If your like me you have to turn the map in the direction I am going as I am not able to invert or read it upside down so to speak.
So again stay in one axis at a time start with the vertical side wall. Decide on a shape you like and then work on that. In my case I really liked the from curvature of the Nose of my trailer. . . It has a 29" radius. At the back of my trailer I had 51" in Height. So that meant a 25 1/2 " Radius. Now simply add the outside radius of the roof spar witch is 17 " and you come up with a 42 1/2" outer circle. To keep things simple I kept roof flat. If you really have some fun and BOGGLE your brain you could do an elliptical shaped roof.
So I then made up 2 templates in the shape of a capital letter, " D ", one with a radius of 25 1/2" and another with a 42 1/2" radius. From these carefully sanded templates I made my shapes At the bottom end of these, " D's ", I found the intersection of the arch which is 7" up. I did this because when going over a sharp incline with your trailer can bottom out.
I had a many pieces of my 1/2" plywood roof spar material made up on a CNC machine. To save on material costs I used 5' x 5' x 1/2" Baltic Birch as it has very few voids in the core. You have to double layer these around 12 " over the seam, . . . glue and screw them together, ( PL 400) . . . to make up one complete spar piece otherwise you will go through insanely large amounts of plywood. I used a jig to keep them all the same just some perimeter strips screw to a large area to make the out to out dimensions . . . basically a 3 sided rectangle.
Anyway I got off track there for a moment . . . back to the rear pantry shapes. The roof spars pieces looked like field hockey sticks. . . . Like a capital letter , " L " , with a rounded corner. From the outside vertical wall my 17" arch travels in perpendicular approximately 21" . . . Hence giving me my pantry depth. After interior Vinyl Fabric is put in my shelves will be 18" deep . . . Plenty of room for storage of everything one should need while camping.
Pardon the long post but I hope this gives you a good perspective on three dimensional shapes. While I was pondering this stuff I went into the sixth dimension to find the answers. It never ceases to amaze me how or brains process information and come up with solutions. I know none of this is rocket science but it is somewhat involved to make.
Cheers
Martin
