Got out in the hangar this morning to do a little work. The task for today was to rivet the rest of the right elevator skin. Pretty easy task with the pneumatic squeezer. Just three different rivet sizes, AN4263-3.5, 4 and 4.5. Those are 3/32 diameter flush heads and three different lengths based on how many pieces if material you are going through. So the right elevator is done minus the rolled leading edge which I will wait for the left side to be ready for that step as I have to set the jig up for that. Then the fiberglass tips which I will wait for the empannage to be finished so that I can work on all the fiberglass at the same time. Next up the left elevator.
Too nice of a day to not take the Harley out for a ride. I have two day trips on Monday and Tuesday so I will have a good week to play in the hangar!
The weekend started off right with nice weather although it is warming, finally. I wanted to give the primer on the right elevator substructure parts a little more time to cure since it is pretty humid here. So I started to work on a difficult project (and a tough decision) on the left elevator. As I have discussed in other posts the left elevator differs from the right in that it has a trim tab. For you non flying types, this tab can be adjusted inflight to reduce the loads on the control stick by helping deflect the elevator in the direction needed. So the left elevator has a cut out for this tab that will attach with a hinge. The side view of the tab ends and the one side of the elevator where the cut out is have to be dealt with. Van’s has you use wood wedges to make a form and bend the aluminum over closing up these ends. The usually leads to headaches if the bend doesn’t go smooth and ends up with a dented and mangled end. I have read several blogs and it made me nervous. The other option is to cut off the ends (the ears) and install a riblet to that area. That was my plan, I mentally prepared myself to this process. For now I will work on just the elevator as the trim tab will be done in the following days. I need to make a run to Home Depot to get some new cut off wheels for my Dremal tool. Once I got back from the Depot I needed to lay out the cut line. I found the line where the bend line would have been and marked it out.
After measuring top and bottom 43 times and remarking a few times I was finally satisfied with the location of my mark. So now was the time to make a cut with the Dremal tool. The plan was to cut within a 1/16″ of the line and use a file to bring the cut right to the line.
After the top was done I flipped the elevator over and cut the bottom ear.
So what to replace those ears with? Several builders have built their own riblet from scratch aluminum. I don’t have any experience with bending and forming tight spaces yet. So I decided to follow another path and use a piece of a E-703 rib. This is a rib that is used in the elevator so it has the right shape already in it. I ordered two extra ribs when I ordered my other parts, due to my earlier mistake on the counterbalance weight, from Van’s. I had one scrap E-703 so that made up the three I needed, one for the elevator and two for the trim tab. So I did some measuring and came up with the right length. I wanted the riblet to extend into the trim spar and tie them together. The problem with that plan was that the elevator skin was already pre drilled to the trim spar. Where the riblet would land in the trim spar had a drill hole right on top of the riblet web line and not on the middle of the flange where it needed to be. I could slide the riblet inward to accommodate this hole but I wanted the riblet to be flush with the edge of the skin for the strength factor. So I then decided that connecting the riblet to the trim spar wasn’t necessary as the the ears that folded over wouldn’t have either. So I took my measurements and cut the end of the E-703 rib on my band saw and finalized the shape with my Scotch-Brite wheel.
This rib was already matched drilled to the end in the elevator during my counterbalance mistake. So the holes in the end where there already and I would need to do some careful measuring. Normally you would have the holes in the skin and drill the riblet from those holes. This time I would work backwards. I’m happy to say that my measurements were spot on and all matched perfectly.
That was a lot of fun! and it was time for a lunch break to give my brain a rest, it doesn’t take much to wear mine out! :-). After a little food and rest I got back at it. Now up was to rivet the right elevator substructure. The plans call for you to rivet the two ends ribs, E-703 & E-704 together then to the spar. I have read several blogs the recommend you rivet the shorter rib, E-703 to the spar first then to E-704. This is due to the weird angle of those two rivets, so that’s what I did. Then I riveted the two ribs together pretty easily.
Next up was the doubler plates and their nut plates.
The other end of the spar gets the E-709 rib and is attached with AN426 flush rivets as the elevator horn attaches over this area.
The plans give you the option on the next step. There are four rivets, two top and two bottom that attach part of the E-713 strap to the skin that will be inaccessible to buck when the spar is in place. They give you the option to rivet those now with solid rivets or later with blind pop rivets. I decided to go solid and keep the look the same.
Now to place a dab of RTV silicone on the ends of the elevator stiffeners that meet each other at the trailing edge to prevent vibration cracks. Then you slide the counterbalance weight in place followed by the spar substructure. I the clekoed the pieces all together.
It was now time to call it a day to get ready to watch the Chicago Blackhawks game! All in all a great day in the hangar
I haven’t had the chance to get in the hangar for few days but today was a perfect day to get some work in. First up was to finish up all the edges of the right elevator substructure. Then deburring all the drilled holes followed by dimpling. In preparation for priming I scotch-brited all the surfaces, fun work!
After I cleaned all of the parts for priming I set them aside to dry. I figured it was a great time to trim the counterbalance weight. There are two weights, one for each elevator. On the right side there is less weight in the elevator compared to the left side. That’s due to the left side having the trim servo and trim tab. The weight needed to counterbalance the right elevator needs to be less than the left. So Van’s has you trim the right side weight as seen on the plans.
I laid out the section that needed to be removed. I placed it in a clamp and used a hacksaw to cut trough the thick lead. Then I used a rounded file to create the radius and a flat file to finalize the size.
The lead weight didn’t take too long to form so I decided to step ahead and start working on the left elevator. Just like the right elevator process you start with matching up pieces and match drilling them. The skin, spar, ribs, trim spar and and elevator horn all get drilled.
That’s where I stopped for the evening to break for dinner and a movie. I’ll be back at it tomorrow morning and will get a good weekends worth of work done.
Today started by creating a couple of useful tools, both get credit from Jason at www.rv7-factory.com. The first is a hinge alignment pin. Due to the tight space where the rudder meets the VS or the elevators meet the HS it is very difficult to get the hinge bolts in place with everything else lined up. This tool allows you to line everything up from outside the confined space. Then you can deflect either the rudder or elevator to slide the bolt in.
The second tool is a bolt retention tool. It will hold a bolt and allow you to get it into very tight spaces. I just used a piece of aluminum from the local hardware store that had the right dimensions I wanted. I made two pieces, one as the handle and the other the clamping piece. I drilled a #12 hole in the clamping piece and used the bandsaw to connect that hole to the edge creating a slot. I then created a slight bend creating a gap when the two pieces are laid together. A couple rivets later and I’m done. It looks like it should work well.
Both of the tools worked well after a little tweaking. Here is the view with the pins in.
And we have a complete VS and rudder!
Next up was to work on the right side elevator. Mostly match drilling and setting everything up.
Each control surface, the rudder and both sides of the elevators, have a lead weight ahead of the hinge line. This is to help balance them and give a better feel while flying. As I was working on the right elevator you have to match drill this weight. Not much fun to drill through thick lead. After you match drill it you remove it to make it easier to handle. Once I was all done with the elevator match drilling a light came on in my head! Something didn’t look right! As it turns out I matched drilled the lead with the head of it pointing inward rather than outward! Oops! Well that’s the first big mistake that requires an order to Van’s for parts. So I ordered a new weight, rib and strap, all that were drilled wrong in the process. I also ordered 2 extra ribs as I plan on cutting off the narrow tips to make riblets for the trim tab and l elevator. More on that in the future. So I called it a day cause its time for hockey, lets go Blackhawks!!
Today was another milestone for me, completing the rudder. The first step was to match and enlarge the holes with the drill. Then I dismantled the leading edge and removed all the blue protective film and deburred the holes. Now was the fun stuff, reattaching the leading edge. That took me close to 45 minutes. Once complete the next thing to do is use pop rivets to secure it.
I’m real pleased with the outcome! The joint is tight and the curves look good, it will fly!
To install the rod end bearings, the parts that fit in between the hinge brackets on the HS you need a special tool. I took a lesson from a fellow builder, Jason, at www.rv7-factory.com and built one. As per his instructions I took a piece of 3/4″ PVC pipe and created a handle. I then took a smaller piece of 1/2″ PVC pipe and cut a slot in the end that was just wide enough for the rod end. That piece was then glued inside the 3/4″ piece after removing a little bit of the outside of the 1/2″ piece. What you end up with is a socket of sorts that works perfect. I went a step further and added a 3/4″ T on the end for a handle.
After installing the rod ends and setting them at the correct length I brought out the VS. I just laid them out to see the layout. Looks awesome!! I decided to call it a night as it was after 11pm and want the neighbors to still like me! :-). Tomorrow I will make a few temporary hinge pins and a tool to hole the hinge bolts in the very tight space.
Too nice of a day to not take the Harley out for a ride. I have two day trips on Monday and Tuesday so I will have a good week to play in the hangar!
