Teardrops n Tiny Travel Trailers

I was reading an American Woodworker and came across an article on Lminations. Thought you guys might be interested in a few points.

Using the right ply thickness

Radius .............. Ply thickness
2-4" ...................... 3/32"
4-8" ..................... 1/8"
8-12" ..................... 3/16"
12" or more .................... 1/4"



Compensate for Springback

FORMULA .............. R|final (n-1)/n=r|form


Example ............ A 5" radius, 10 ply lamination

5"(10-1)/10=45/10=4.5"
5"=project radius ......... 10=number of plys .......... 4.5=form radius


Hope thats clear......

...as mud.
???

Micro469 wrote:
Using the right ply thickness

Radius .............. Ply thickness
2-4" ...................... 3/32"
4-8" ..................... 1/8"
8-12" ..................... 3/16"
12" or more .................... 1/4"

FORMULA .............. R|final (n-1)/n=r|form

Hope thats clear......

So, start with the correct ply thickness for the final radius you want and figure out how many plys you will use.

To get the radius for the form, you multiply the final radius by the number of plies minus one divided by the number of plies

For a 5 inch final radus, using ten plies (each of which must be 1/8" thick), you would do this to get the radius of the form for laminating:

5 x (10-1)/10 = 4.5

What I am wondering is whether this was for a circle, a half circle, etc.

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edit, well, uh, more like a greater-than-a-half-circle intead of a circle.

Thanks for posting this. Does this mean if my radius is 24" (per lil dinner) then I just need 1/4 in ply in any combination?

Miriam

Edit: Or does it mean a 1/4" ply will bend to meet the radius???