The joining of the main spar to the center spar is something that I have thought often about over the time that I have been working on this project.I am finally to that point. There is also very little information describing how others have tackled this important step.

In the video below I describe some of the preparations and setup I am doing for maximizing the chances of getting this important step correct. Hopefully the information presented will be useful

There will…

While making the bends for the front and rear center spar uprights, I had a problem trying to take measurements with any of the numerous protractors I had. The angles I was trying too measure were to acute for any of my protractors to fit. So I decided to make a set of simple angle gages.

The gages were made using .025 aluminum scraps that I had laying around. The key to setting up the angle is to use a machinist tool called a sine bar. Referring to the picture below, the sine…

Fabricating the front and rear uprights for the center spar posed an interesting challenge. Each is about 18 inches long. One has a thickness of .063 inches. Which if that were all I had to deal with, I could bend it in my regular leaf brake and be done one with. However the other pair is 1/8" thick and I think would be a little too much to bend for the leaf brake.

Fortunately I have a hydraulic press and also a 26" press brake to go along with it.The problem with the press…

While working on the center spar I had needed to attach the doublers. The problem is that the body of the centerspar had  1/4 inch holes already drilled into them, but the doublers only had 3/32 starter holes. It is no problem drilling out the first hole to 1/4", but how do I make sure that I am centered as closely as possible  over the other other 1/4" hole.…