- Ribs Fluted and Deburred and Nearly All Cleaned
Here is a shot of the HS ribs marked, separated into Left and Right sets, and half are cleaned and deburred. I fluted using my fluting pliers and they all came out straight. A little more cleaning and they will be ready for assembly into the skins for match drilling and beyond. I am almost to the point where it will look like I am starting to build a plane.
One Side Drilled, One to Go
After the HS404’s are notched, the next step is to mark and drill the forward flange of the HS405 ribs. These are located between the forward spar and the rear spar of the HS. The tricky part is making sure that the holes you mark and drill here provide adequate edge distance to not only the flange you are drilling, but the flange of the HS404 tab that was left after notching it, and the stiffeners on the forward spar. I followed the plans to the “T” and still measured 15 times.
I noticed that while the ribs are symmetrical top to bottom, the bends for the skin flanges are not. This means the forward tab is higher than the other if you place these back to back. So, as you can see, the marks on the tabs above are not exactly a mirror of each other. They are offset by the differential in the bends for the flanges being different.
That being said, I was able to mark and drill so that it met all the required distances and compensate for the offset of the tab just fine. This will ring true when they are matched drilled to the spar and stiffeners and the leading edge ribs (HS404’s).
I also learned the value of a good center punch. Makes locating accurate holes a breeze.
HS404’s marked per plans
One of the next steps after getting the Fore HS Spar prepped is notching the inboard leading edge ribs for the HS notched to go around the stiffeners prepped in earlier steps.
Here you can see the full size detail on the plans and the ribs with the areas that need removing marked in red. I first drilled the corners with a #30 bit and then rough cut the edges close to the limits with my band saw. Then I cleaned up the edges of the cut with a fine file until they were blended with the holes in the corners.
Here is the result:
HS404’s after Notched Per Plans
They are spot on with the plans and ready to be drilled to the spar. The trick is…TAKE YOUR TIME and file as little as needed. I am learning patience in these early build steps. I think that will be the more valuable lesson as the build progresses.
