mark IX

My Feedback: (9)

I am about to start sheeting the foam wing cores for my 69" ws P-51. I am wondering if the wings need spars added for strength? I was going to add to each panel, (2) 1/4 x 3/8 spruce spars, top and bottom, from the root to the tip, as you would do on the plans for a built-up wing? Is this overkill?

Thanx, Mark

Outrider6

My Feedback: (2)

Just my opinion, without engineering calculations, but I think spars would not be necessary on a sheeted foam wing. Over the years, there have been lots of such wings flying just fine. For example: SIG Kougar and King Kobras have sheeting only, with no spars. Adding spars would add complexity and weight, with just a little gain in strength that isn't needed.

mark IX

My Feedback: (9)

This is kind of my feeling as well. But this being my first foam wing, I wanted to get opinions with other experienced builders, thanx.

Mark

mark IX

My Feedback: (9)

So I guess I only need to add spars in the retract area, around the wheel openings, etc. There must be a tutorial about this.

sensei

You need to add servo rails for ailerons/flaps and anything like wing tube sockets if applicable. Here is a buddy of mine holding my wings.

Bob

After sheeting

Before sheeting