4.8 Hours -
Things were rolling today until I had to take a break to fix my broken back-rivet set… twice. More on that later.
I started by deburring and dimpling the rear aileron skins. For now, I’m only working on the holes that will be used to attach the stiffeners.
Most of the dimpling on the rear aileron skins had to be completed with a c-frame.
The stiffener rivets are all taped into place and ready to be back-riveted.
Once the skins were prepped, I started to back rivet the stiffeners. On the second stiffener, my back rivet set broke! Specifically, the split tension pin that holds the plastic collar on, broke and fell out. I had to take a break to go find a new one of these. Lowe’s didn’t have any small enough, but the National Aircraft Parts Association (NAPA) came through. I also picked up some more Scotchbrite pads while I was there.
When the back-rivet set was fixed, I continued riveting the stiffeners. Back-riveting is quick and easy, but I hate working on the trailing edges of these partially bent skins. I had to use duct tape to keep the skin bent back and out of my way. It’s not complicated, just a hassle. When I got to the last stiffener, the pin in the back-rivet set broke for the second time. I’m not sure what is causing the pin to break…something must be rubbing on it. It may just mean its time to get a new set! Fortunately, the collar was still staying in place and I could finish the last two rivets.
While riveting the second stiffener, the split tension pin in my back-rivet set broke and I had to take a break go find a new one. The new pin is in the picture.
All the stiffeners are back-riveted to the rear aileron skins.
The outside view of one stiffener's rivets after back-riveting.
On the last stiffener, the new pin in my back-rivet set broke. This is ridiculous...at least I was able to finish. Maybe I need to get a new set because these pins shouldn't break so easily.
After the stiffeners were riveted, the trailing edge bends in the skins could be finished. The other day, I pulled out the bending brake I used on the empennage and figured it would be too warped by now to use again. However, it was still perfectly straight. Unfortunately, it was about 5 inches too short for the aileron skins. Not wanting to chance a screw-up from using a brake that isn’t full width, I decided to build a new brake. I purchased the wood a couple of days ago, so all I had to do was take the hinges off the old brake and install them on the new boards.
I had to make a new bending brake for the rear aileron skins because the one I built for the empennage was too short. Make sure you make yours at least 5 feet long!
Using the new brake, I completed the bends on the aileron skins. I had to bend them as far as the stiffeners would allow in order to get the proper bend, and I temporarily clecoed in an end rib to make sure the bend was correct.
The rear aileron skin in the brake, ready for bending.
The rear aileron skin after bending.
I then moved on to the aileron spars. The first step is to fabricate four reinforcement plates that will go on the ends of the spars. The plans tell you to cut these to the proper size using scrap, but they actually send them to you already cut to size. Fortunately, I remember this and I remembered where I stored them! Once located, I clamped them to the ends of the spars and used the holes in the spars as a guide to match drill the plates.
The reinforcement plates are match-drilled to the aileron spars using the holes in the spars as a guide.
After the reinforcement plates were drilled, I drilled the aileron brackets to the spars/plates. The aileron brackets are already pre-punched, but the holes needed to be enlarged to #12 in order to accommodate AN3 bolts. Now that the plates and brackets are drilled, I need to take everything apart for deburring.
The holes in the aileron brackets need to be enlarged to #12 for AN-3 bolts. This is the inboard bracket.
The outboard aileron bracket.
The reinforcement plates and aileron brackets have been drilled to the spars. Time to disassemble and deburr.
