Well tonight I actually started work in earnest. The first thing that hit me as I was separating the plywood ribs from their sheets and labeling them was the weight. W1, W1A and W2 were very heavy in my hand. I set them aside and continued to separate the rest of the balsa ribs from the sheet. After I glued up the spars with their doublers I pulled out the digital scale and weighed the plywood parts. They weighed a total of 4.8 Oz. Now I am doing a lot of modifications to this plane one of them being that it will be sheathed, and then finished using carbon fiber veil applied and then finished with dope. By doing so I hope to gain some strength without adding a lot of weight to the finished airframe.
It is going to have hard points on the fuse for carrying both payload and weight, one reason is for utility purposes and the other to work on my skills flying a plane with high wing loading.
Now with this having been said we go back to the weight thing. I want to maintain the flying weight target of this plane at the design range of 4 to 4.5 lbs. That is a total weight less fuel and payloads, so I have a 64-72 oz. range. The engine I am going to use (OS 55ax weighs a total of 18.6 oz. So let’s take that right off the top that give me 45.4 to 53.4 oz left for the airframe, servos, receiver, landing gear, and battery. So now if we look at that 4.8 oz we can see that that is roughly 10% of my total remaining weight.
I figure I can lose some of the “slab of wood” by adding some lighting holes to the ribs. So I marked them off tonight and will drill them in the morning on the drill press.