Hi all:

Need some help cutting foam cores for a Midwest Extra 300S. Have the Root and tip templates cut out and ready to go, But need some help with positioning the templates on the foam blocks.

It is my understanding that the top of the wing is flat and the bottom has dihedral. Root rib is 2.5 inches thick and the tip rib is 1 inch thick. If I put the templates on the center line of the block, the top of the wing will not be flat. What do I do? Where do I set up the tip template?

Any assistance will be appreciated.

Dennis

I don't know much about it, but can't you just sand the dihedral in afterwards. Where ever you put the tip top to bottom opposite of the root, the dihedral will dictate the shape, right? Even if you move your position front to back, It can still be adjusted at the root. Let me know if this helps at all.

Lets see if I can explain this without a diagram.

when the root template is in place measure from the top of the foam block to the top of the airfoil template high point. When placing the tip template on the block use that measurement to position the template, ensuring at the same time that the airfoil centre line is parrallel to the root template centreline.

Ed S

Either way will work, I cut a symmetrical core and then join them inverted on a flat surface when I scratched two of those. KISS, It's a model airplane not a space shuttle.

Spar recomended, it makes for a heavy plane, I didn't like it as well as the built up wings