456 hours - pulled down the lonely HS - Prep for fitting the elevators

Managed to get the HS down off the wall all by myself. No new dings as far as I am aware. I forgot just how large 8.5 feet is. Lots of dust to clear off, and everything needs a good cleaning. As soon as I started looking it over, I started having flashbacks to all the "moments" during the HS build where things did not go exactly according to plan. Of course there is the major ding on the top skin, the major forward spar repair, the hard-to-set forward rivets on the tips, Several smilied rivets, and many scratches, dings, and just plain not very good workmanship IMHO. I did not even ground down my soldering iron well enought to remove the vinyl coating around the rivet lines, so I also have several small scratches in the skins as a result of that. Then there is all the divets and scratches from bad flush riveting where the mushroom rivet set in the gun has either dented the skin around the rivet hole or severaly scratched the alclad surounding the rivet. Not very impressed with the exterior of the HS to say the least.  Oh well, I will let the tech counselor rip to shreds when he comes to visit, and go from there.

A reminder to other builders - make sure you disregard Vans build sequence they have laid out in the plans, and START WITH THE VS FIRST INSTEAD OF THE HS! The HS is NOT the best thing to start with, as there are many complex steps involved in this part of the build, the parts are smaller, and you have to build two sections. The VS is a much better build for learning how to handle all the new tools, clamping procedures, and riveting/bucking techniques. Also start off right and grind down the edges of your yokes and any other tools that do not have correct clearance. In the world of flight instruction, we have a saying:

Do not let the airplane fly you - YOU fly the airplane.

This addage can also be applied very easily to building this kit:

Do NOT let the kit determine the quality of the build, YOU determine the quality by using the right tool for the right job, taking your time, and seeking assistance from other builders/chapter members when needed.

I may very well drill out the rivets and remove both HS skins and order some new ones, unless the tech counselor can convince me that this is not necessary. It would be a lot of work to do this, but I think the skins would turn out so much better now that I am a bit more seasoned as a builder

Here are the elevator leading edges sitting next to each other. I wanted to compare the contour of the rolls on each one to see how symetrical they are.

Next is the HS turned upside down, and the left elevator roughly placed into position so I can check some measurements and initial fit of certain areas.

Next is a pic of the center section where the elevator control horns sit next to the center hinge bearing, It also shows some lines I drew with a sharpee to mark the area of the bottom flange of the rear spar on the HS that must be trimmed away to allow for proper range of motion of the elevators when they are moved in the down direction. I set the length to 1 inch from the edge of the center bearing on both sides (26/32" is the minimum necessary to clear the flanges of the control horns on both sides, but I figured that rounding it to an even inch was acceptable. The depth measurement is 3/8". I have it on good authority from several other builders that this is more than adequate to allow for proper range of motion of the elevators. I will radius the hole 1/8 of an inch, which means a center punch 1/8 of an inch out from the inside corners to allow for a 1/4 inch drill bit which will create the 1/8 inch radius that I need. No such trimming is needed on the top flange of the HS rear spar, since the elevator control horns do not interfere with anything on that side.

You can also see the gap between the control horn and the center bearing. This is normal and will be closed up by adding as many washers as are necessary on the bolt between the control horn and the bearing on both sides.

And finally is a pic of the tip section. There is more trimming of the HS skin required in this area in order to clear the tip of the counterbalance arm. I will use the same process as I did for trimming the bottom flange of the rear spar of the HS. Only question is how much clearance to leave between the counter balance arm and the HS skin. I see absolutely no mention of this in the plans at all. It may be as much as 1/4 inch or as little as 3/32 inches. I'll have to inquire about that. Tomorrow I give the HS a bath and trim the flanges on the rear spar. I also need to go get a #13 drill bit which I will use to pre-drill the hinge holes on the HS, and will follow that up with a #12 reamer. Once the hinge holes are properly reamed to size, I can use the temporary hinge pins to trial fit the elevators and check for range of motion in both directions and binding.

You can see the slight overlap of the HS skin on the right side of the pic. This overlap will be much greater when the rod ends are inserted all the way into the hinges.

455 hours - finished riveting the LEs - Rod end Bearings, and Torque counterbalance hardware

Had to drill out a few rivets and re-do them. Obviously I fixed the pop rivet gun problem. That is honestly only the second time since I started this project that I experienced some sort of tool failure. Both of them were temporary and were caused by aluminum chips or fragments getting into small places - a good reminder to keep the shop as clean as possible at all times, which is something that I have not been doing lately.

Here is the left elevator all buttoned up

I used the torque wrench to tighten down the screws and lock nut to 25 inch pounds per the plans and torque specs for the hardware. This was also my very first time for applying torque seal to the nut and bolt. Got kind of messed up on one of them, but the rest came out OK.

NExt is a pic that shows the differences in the pop rivets I was using to close up the LEs. Still not sure if the one without the mandrel on the end is a defective rivet or not, but will call Vans tomorrow to discuss. The other mandrel in the pick that still hS the head attaached to it is the one that pulled completely out of the hole without breaking. The remaining "debris" is some of the rivet heads and shafts that I had to drill out and replace. Thies rivets are pretty easy to drill out, unlike the one that had to do on the trim tab a while back.

Next are the rod end bearings - two for each elevator. Plans say to screw these in so that there is 13/16 " from the spar web to the center of the bearing hole. Some have devised very elaborate methods for doing this, but I found that an eyeball technique seemed to get me close enough. The real test will come after the elevators are installed on the HS. I took one of the bolts tat goes in the hole in the center of the bearing, inserted it in the hole, adn was able to hold it pretty stright by applying vcointer pressure against the back side of my finger on the edge of the elevator skin of the cutout, while pushing the bolt in firmly against the bearing, and checking the alignment ofd the bearing and bolt to see if it was parallel to the spar web. WIth the bolt held in position, I took my small ruler, butted it up against the spar web, and layed it over the top of the bolt shaft on the other side of the bearing. Then I read the measurement at the preceived center point of the bolt.

Not horribly exact, but good enough to get within a half turn of a rod end if the need arises, when I trial fit the elevators to the HS.

At this point I don't really want to call the elevators done yet, since some touch up primer is needed in a few places and some debris and shavings need to be cleaned out in certain areas. I will do this tomorrow, and then attempt to get the HS off of the wall. There is still some trimming and fitting and drilling to be done with the HS, but that should go relaitvely quickly.

I am a little leary about rushing this, however, especially after reading a recent post from a builder who wrote about problems with his RV 10 elevators rubbing on the inside edges of the rear spar rivets of the HS. This was possibly due to not setting the rod end bearings to the correct distance. Problem is he had also already drilled the holes in the control horns which pretty much sets the distance of the rod end bearings in stone. If you try to adjust them the center bearing will bind up. Another builder wrote that he checked everything thoroughly after the elevators were done, just as I am about to do, and everything seemed fine with the HS and elevators off of the  fuselage. But when he mounted everything to the fuselage he encountered the same rubbing problem.

I really want to make sure I do this correctly, so I will once again take my time and make sure that the rod end bearings are exactly where they need to be. I am not very convinced that my LEs are symmetrical or that each separate section is evenly shaped, especially since the process to form them is anything BUT precise. In the end I may decide to move them to the outer limit in the plans which is 7/8 of an inch, or about 1/16 inch more than the suggested measurement of 13/16 for the rod end bearings. Once you drill the center bearing bolt holes into the control horns you are committed. If you screw up the rod end bearing placement, you may very well end up building new elevators, or you will have to figure out how to repair, redrill, or replace the control horns - none of which I wish to encounter later on down the road.

454 hours - riveted leading edges of both elevators

Well, I have to admit, and any of you following blog site already know, that I seriously doubted if I was ever going to see this day arrive. I finally got to the point where it was time to rivet the elevator leading edges together for what I hope will be the last time for the rest of my natural life.

A new first was the use of a little present that I got from Mike Rettig a while back that I had not yet had the chance to use. It is a pneumatic blind rivet puller from harbor freight. This little tool (well, it is NOT so little, as you will soon see in the pics) worked wonderfully up to a point, and then I had some issues that seemed to resolve themselves somehow. I was able to use it on all the rivets on the LE except for the one closest to the outboard tip on both elevators. That last rivet is tool close to the counterbalance skin and ribs to allow it to be used, so you ahve to revert to the hand squeezer for that one. More to come on that topic in a bit.

Here is shot of the right elevator all buttoned up. Came out OK.

I have one episode of a rivet that did not set correctly. I had to drill it out and set another one, and then I noticed something really disturbing about the AD41 ABS pop rivets I was using. Many of them seem to be missing the mandrel on the end, and I can't tell for sure if this is by design or if this is a flawed pop rivet. I am not even sure if the one that failed was one that had the missing mandrel tip or not. Basically what happened is that the mandrel never broke off as expected, and it continued to pull all the way through the hole. Turns out there was a tip on the end but it never broke off. I'll get a pic of that tomorrow.

Anyway - the pneumatic rivet squeezer works pretty slick. In one trigger pull it sucks the rivet stem up, sets the rivet, and deposits the stem in the back of the tool in a nifty little catcher. The action is very smooth and about 99% less violent than when i breaks while using the hand puller.

Here is the manual puller on the left, adn the pneumatic puller on the right.

Since I had a bit of a problem with burs in the holes that I drilled on the right elevator, I decided to take a different approach on the left elevator by using reamers to create the holes for the rivets. The process basically went as follows:

1. Cleco the holes and use duct tape strips in between the clecoes to secure the top and bottom skins together to maintain the hole alignment while the rivets are being set.
2. Ream the holes with a #40 reamer. They are already punched to #41 hole size, so the #40 reamer will work perfectly as a starting point.
3. Drill the holes with a #31 drill bit to prepare the hole for the #30 reamer, which is the final size that is required to fit the pop rivets.
4. Ream the holes with the #30 reamer.

This process left very clean holes with essentially no burs to worry about.
This next pic shows the #30 and #40 reamers, and the #31 drill bit.

Next is a pic of my 12 inch long extended #30 and #40 drill bits. I needed to use both of these for the last hole next to the tip that mentioned earlier, because you also cannot get a drill in there to safely drill out the last hole without risking marring up the counterbalance skin with the chuck on the drill. This method or an angle drill would probably work OK.

Next is the left elevator, inboard section has already been drilled and riveted, and the remaining sections are clecoed and taped as desribed earlier.

Next is the inside of the inboard edge of the right elevator The skins have mated much better than the way the rudder turned out, which I now admit I will most certainly redo, now that I know what I need to do to make the skin form correctly.

And finally a shot of the outboard section on the left elevator. Note the copper cleco for the #30 hole that I have already drilled with the extended length drill bits.

I managed to rivet everything on the left elevator until I got to the last hole. Then I started having problems inserting the stem of the pop rivet into the manual pop rivet gun. I had to stop because I had no way to set the final rivet. What a fitting end to this long drawn out episode of the build. Just seems like it wants to keep scratching and clawing its way against your every move.  I wanted to be livid about this, but instead I guess I was resigned to the fact that this was probably going to happen anyway, just because of the way the elevators have gone thus far. So I stopped and went to a movie to regroup.

I then started looking over the rivet puller. I even disassembled the damn thing trying to figure out why the rivets would not insert into it. I finally found a small sliver of metal that somehow had imbedded itself inside the adjustable head that screws into the rivet puller for the correct size rivet you are using. So it wasn't a problem with the insides of the puller itself - just some junk aluminum that somehow found its way inside the small hole of the insert. It's too late to set the rivet now, so I will finish it up tomorrow. At least I now know what to look for, and I also know a bit more about how the puller is assembled.

Rod end bearings will be next, and then drilling the center bearing hole in the control horns.

451 hours - Rolling the left elevator

A big thank you to my fellow aviator and neighbor Kevin Shepard and his father Bill. Kevin answered my call for assistance to get the left elevator leading edges rolled. His father was visiting and wanted to take a look at my build, so of course I put both of them to work as soon as they arrived. It sure is helpful to have many sets of extra hands during this process.

Only differences between this episode and the one for the right elevator is that I used only 2 sections of overlapped gorilla tape instead of 4 to attach the water pipe to the skin, and I used the 3/4 inch OD pipe for both top and bottom skins instead of the small one for the bottom and the larger one for the top. I did not mean to use the same size pipe on both sides - just slipped my mind. Anyway, I think it worked out fine this time. 2 pieces of tape worked great adn the bends came out just fine. Oh yeah, I also did not roll the edges very far at all. Maybe 35 degrees tops. This worked out very well as the edges of the skins were much closer to where they needed to be by the time I finsihed hand forming the rest of the bends oin each section.

The left elevator is also a bit different than the right in that it is essentially split into 4 sections instead of three. This is due to the slot that is cut in the inboard section to allow for the manual trim tab cable, should one desire to install that trim system. Since I am installing electric trim I will ahve no use for this slot, but that is the way the skins come from the factory. This actually makes bending the leading edges a little easier since it reduces the overall size of one of the sections. That middle section is still a bear to get positioned correctly.

I almost have everything positioned where I want it. I will tweak it a bit more tomorrow before I final drill the holes and set the rivets on both elevators.

This pic shows clecoes installed on all rolled sections"

And I reprimed the bottom skin of the right elevator. Should be able to close that up tomorrow as well. The primer on the left elevator actually did not come off when I removed the tape from the bar and the skin. Must have had enought time to cure hard to the metal or something. So at least I only had to reprime the right elevator.

I am still a bit concerned about the burs from drilling the holes in the right elevator, but I think I knocked them down as best I could.. I think I will use the reamers on the left elevator instead of using the drill bits to see if I can keep those holes a little cleaner. 

A p.S. to the previous post

I forgot to mention in my previous post that I went searching for some information in my blog way back during the rudder final assembly, and I found what I was looking for. I was wondering all this time while finishing up the elevators how I managed to NOT strip away all the primer on the leading edges of the rudder when I rolled those LEs.

The answer: I rolled the bottom or underside edge of the rudder first, and THEN I applied the primer afterward. So the tape never touched the primer. So if I would only have spent the time to carefully research my own previous posts, I would have realized this, and would have avoided having to repeat the steps to reprime the leading edges. Live and learn  I guess.

Somebody asked me if the tape should be able to strip the primer off of the metal like that. My answer: The gorilla duct tape I am using can strip just about anything from anything IMHO, especially from cold aluminum with a primed surface that was stressed during the rolling action. I will be deburring the holes and positioning the LEs so I can reprime them again. I will have to remask the entire elevator just as before and repeat the primer application. Just a minor setback, but a setback nonetheless.

448.5 hours - Right Elevator LE skins finally form fitted - drilled holes to #30

Man ya just gotta love this February winter weather we are having. The TV folks said we should get about a half inch last night. Woke up to 9 inches of the stuff on my driveway - another dig out - yippee. Oh, and then the winds were hurricane force around here for 2 days prior to that.

Anyway, I managed to get a few things done in the airplane shop tonight before it got too cold. I worked on the middle section of the right elevator, and finally got the skins to lay pretty flat on top of one another. Then I drilled the rivet holes - #40 first, followed by #30, for the pop rivets that will close everything up. I stopped at that point because I still need to re-prime the inside skin before I close them up for good. A little primer and deburring some holes, and I am done with the right elevator. (well, almost.....)

I also needed to go back to the left elevator for the third time and set my rivets a bit more. I did not get them squeezed quite well enough on the first or second attempt, but this time they are set to my satisfaction.

Tomorrow I will finish up the right elevator and Roll the LEs on the left elevator.

Elevator LE Pics from last night

So here are a couple of pics of the leading edge roll experience for the right elevator. The first shows some residual waviness of the mid section that I need to resolve. Problem is that this means that the top skin (the one that overlaps the bottom), needs to be pushed down a bit more, and this unfortunately means that I need to reverse the skins so that the bottom is on the outside and the top is on the inside. This is the only real way that you can apply enough force to the skin that needs to be bent. Switching the skins around becomes much more difficult when they start to overlap each other. I also need to reapply primer to the bottom skin edge, so at least I have two reasons for switching the skins around. Sure hope it is worth chewing up my fingers and hands again to finish this up. Did I already say that this is the my least favorite part of this build.

Those gaps have got to go -almost there.

Next is the entore elading edge. The top and bottom sections are laying down fairly well now, so only the middle needs some work. Oh yeah, and I still need to do the remaining 4 secttions of the Left elevator.

447 hours - finishing the LE roll on the right elevator

So after devoting an entire nice building weekend to the completion of my 2011 taxes, I finally got to go out to the shop tonight and continue working on the dream. I had partially completed the roll of the leading edge of the elevator. Now came the hard part - forming the final curve by hand for the bottom and middle sections.

I must say that I agree with others that have come before me that say that the middle section is the hardest one to finish. It makes sense if you think about it. The bottom section is the largest, and it is also a fairly long stretch of metal. The fact that the skins are larger at the bottom due to the taper of the leading edge (skinnier at the tip and wider at the root), means that it is a bit easier use your hands to work with it and form it the way that you need to. The tip section, by contrast, contains the smallest length of skin, as well as the smallest radius of all the sections. Even though it has a smaller radius than the bottom section, which generally makes it harder to work with, the short length of the tip section also makes it very easy to form into the final position for riveting.

The middle section, on the other hand, has a smaller radius, which makes it hard to get fingers and hands in all the right places to work the metal, AND it is also a very long section of metal. This results in a great deal of resistance on this section of skin. It wants to act more like a spring than a piece of metal that can be easily shaped to final form with your bare hands. It takes some creative work with your hands to get this section to fit correctly.

I managed to get the bottom and middle sections rolled into final position to the point where I am almost satisfied with them. The top middle skin needs a bit more work to remove some separations from the bottom skin - a few tweaks in just the right places to push the skin down a bit further to seal the gap. Unfortunately this is a bit more difficult than it sounds, especially when the top and bottom skins start to overlap with each other as they get closer to their final positions.

I'll post pics tomorrow since I'm too tired to do it now. Sure felt good to work on the plane again, even if my fingers, hands, and arms are tired from all that intricate metal forming!

Preparing for drilling the holes for the Center Elevator Hinge Assembly

Sooner or later in this process you have to become intimately familiar with Aviation quality hardware and tools. Once the elevators are finished, the next step is to temporarily hinge them in place on the HS, one at a time, and center them up with the HS so that mounting holes can be drilled in the control horns. These holes must closely fit the 1/4 inch bolt that secures each control horn to the center bearing assembly, which was the very first  assembly of the tail kit that was riveted together many many many months ago.

You also learn the difference between close-tolerance and other types of hardware. The holes and bolts that that are used in close tolerance applications are designed to prevent excessive play in the components being attached by providing a very exacting fit. Abnormal wear on the hinges and bearings, control flutter, and control binding are just a few of the potential problems that can result if both the holes and the bolts are not properly sized and attached.

The assembly of the center bearing/hinge on the HS, and the drilling of the mounting holes in the elevator control horns that accept the bolt that is inserted through this bearing, must be done exactly right. Vans tells you to "make" a center bearing insert or drill guide of sorts that has a 1/4 inch OD and a 3/32 inside diameter (ID). A pilot hole is then drilled through the exact center point of the hole in the center of the bearing. After reading several posts on VAF and comments on various builders logs to determine what to use for a drill guide, I discovered a couple of solutions, either of which should work quite nicely.

I am very fortunate in my part of the world in Denver Colorado to have access to a hardware store known as the A&A Tradin' Post. It is an independently owned and operated hardware store in this area that is the "go to" place for hardware items that cannot be located anywhere else. It is the only place of it's kind within a 4-6 state region as far as I am aware. They do not supply aviation-grade hardware, but they do stock tools and other hardware items used for building the airplane that may be hard to come by elsewhere, and this can come in handy.

The pic above shows 3 drill bits, a set of aluminum bearings, and a set of nylon bearings. OD dimensions for both bearings are about 1/4 inch OD, and have slightly different inside diameters that will accept very specific sizes of drill bits. Each one is also 1 inch in length, which works well for drilling the pilot holes in the control horns on either side of the bearing. While neither of them has a 3/32 inch ID hole as called for in Vans plans, they will still work well for drilling the pilot hole in each control horn. The final hole size is supposed to be 1/4 inch, so any smaller sized drill bit should be just fine for drilling the pilot holes.

The nylon one can be found at Lowes stores,and several builders use this one for the drill guide. Not having  the best success with drilling out holes in the lead counterweights, I was just a bit concerned about using a lense dense material as a drill guide. Several others on VAF said that the aluminum one gave a more precise and sturdy platform for the drill bit, and the end result is a more precisly drilled hole in each control horn. Problem is that most builders that opt for the aluminum bearing find one that is supplied by an aviation hardware supplier, and the postage alone for shipping it is ridiculously expensive. This is a waste. I was glad that I was able to find an aluminum bearing locally at A&A instead having to order it from the supplier. As I said earlier, if you have ever had to locate any oddball type hardware in this region, you already know that the chances that A&A will have it are very high, so I expected nothing less.

Now back to the hardware lesson. Again with thanks to the experts on VAF, I have learned that drill bits are sized in about 3 different ways:
by wire size (numbered)
letter size (A-Z)
fractionally, which is what you typically see at the home improvement stores and most hardware stores.

Each of these methods has a range of different tolerances under which each bit is milled. Drill bits that are milled using one method may be slightly smaller or larger than similar sized bits that are created using a different sizing method. Then there is the added variable of the person, method, and tool used to do the drilling. Using a hand drill, for example, can be less accurate than drilling with a drill press, and sometimes the opposite can be true.

The best procedure for drilling these holes as accurately as possible is to find a drill guide that will fit snuggly in the inner race of the hinge bearing with a truly straight center shaft, and then find a drill bit that fits as closely as possible inside that center shaft without going over. Once the drill guide is in the hinge bearing, you place the drill bit throught the hole in the center of the guide, and drill the pilot hole in the control horn. Then you remove that elevator from the HS, mount the other elevator, and drill  the hole in the other control horn in the same manner. It is absolutely imperative that the elevators be properly aligned with the HS, and that they are secured tightly in place, with no possibility of moving while the control horn is being drilled.

To make matters even more challenging, several builders have reported that they ended up with a hole in the control horn that is too close to the weld that holds the parts of the control horn together. When this happens the head of the bolt and the nut on the other side do not have enough turning or tool clearance, and the hole has to be filled by welding it closed again, or by applying a patch and redrilling it again.I do not want to go through any of that crap, so I will take my time here, just as I did with the trim tab.

Anyway, the aluminum bearing from A&A Tradin Post accepts a number 27 drill bit quite nicely, and the nylon bearing accepts the slightly smaller number 28 drill bit nicely. I will use the aluminum bearing and the number 27 drill bit that I purchased from A&A when the time comes to drill the pilot holes through the control horn, and I will make careful measurements ahead of time to verify that there will be sufficient clearance for the bolt head and the nut to turn freely.

The last drill bit in the above pic is a Letter D size drill bit, which turns out to be just a few thousandths smaller than a 1/4 inch drill bit. This is the bit that I will use for the final step drill of the holes in the control horn before I switch to a # 12 fluted reamer. Why use the reamer instead of the 1/4 inch drill bit? The Reamer leaves a truly round hole that is much cleaner than one created with a drill bit. I found out that not only did A&A have the aluminum bearing I wanted use for my drill guide, but they also have full sets of drill bits in either of the three sizing methods that can be purchased individually on an as needed basis. Nice to know I can get whatever size bit I need for future applications.

Before I get to that point, however, I still need to wrap up rolling the leading edges..... hopefully tomorrow.

446 hours - Let the rolling begin

There is nothing like a complete computer melt down due to a virus and tax season to put a damper on your efforts to build an airplane. It's been a rough week all around, but I am back in the saddle and have a few pics from last weekend to get caught up on. I basically started rolling the leading edge of the right elevator and also did some prep work for drilling the center bearing bolt holes in the control horns once the leading edge work is done.

First thing is first - I needed to kerf the leading edges of the top skin on both elevators by using the edge roller tool. Same process as when I did it for the rudder. If you can look past all the smudged finger prints, you can see the small crease in the leading edge where the tool did its job. This is important for ensuring that the overlapped skins will rivet together cleanly, without curling up at the edges when the rivets are squeezed.

The idea is that you want to kerf the top skin so that when it compresses down on the bottom skin underneath the two edges will mate together nice and flat. The top needs to go on the outside to help shed water that may accumulate on the leading edges from rain or slush on those less than perfect weather days or when you need to wash the airplane.

the bottom skin needs to be primed where the skins will overlap. In the event that any moisture does penetrate this area you want to do your best to prevent sources for corrosion. Since this is a common area where corrosion can occur iit is in your best interest to apply some form of protection here. My advice is to wait untl after you bend the leading edge, because when I put duct tape over the leading edge with the primer to roll the edge, most of the primer got lifted off by the tape when I removed it. I need to go back adn see how I did this for the rudder because I don't remember having this problem when I worked on it.

Oh, well,  just have to respray it this weekend adn close everything up.

Now, in this next pic, can you tell if it is cold outside or not? I'm sure the hat and heavy coat don't give it away at all! BtW, this was in the garage with the heater cranked up full blast and the insulated garage door closed. Yup, it was cold. Wasn't goin to let that stop me though. I am taping up the bar on the mid section of the elevator in this next pic. Those that follow show the end result:

I decided to try some different techiques this time from the way that the rudder was done. Namely they were:
- I did not use the fancy bend table or the U bolts to hold down the bar on the table while I cranked on the bar to roll the skin. I ahve seen too many pics where everyone just tapes it up adn starts cranking, adn it all seems to turn out fine, so I thought I would try that approach. What I found is that you still have to be very conscious about pushing down and rolling at the same time so that you do not crease the skin where it joins the flanges of the forward spar.
- I did NOT want to roll it so far that the edges of the skins were already perpendicular to the spar before I even start closing them together. This got me into serious trouble with the rudder, because the inside skin ended up being rolled too far, aand I may still decide to open it up adn try to correct it a bit. But for now I will try to get the elevator skins right on the first attempt.

In fact, it turned out that even though I thought I had only rolled them just far enough, the inside skin still ended up being a bit over rolled. Personally I would say that you only need to roll the leading edge so tyhat it sits about 30-35 degrees up when you remove the bar and the tape. Don't even take it to 45 degrees or you will ahve the same problem I do. It really takes a lot of hand contouring the skins to get them to close up adn to ensure that the edges are laying flat against each other.  SO less is more for this part of the operation.

- I did find as others had told me that the elevator skins a re a bit easier to work with than the rudder. The technique to finish the rolling by hand is still an art form, however, and I can't even really describe how you need to do this very well. It is a combination of using the upper pad of the palm of your hand and the bottom portion of your fingers to gently and slowly push the initial bend of the skin closed until you finally reach the mid point where the top and bottom skins will overlap. The rest of the technique is figuring out how to push UP AND AWAY on the skin to keep it from forming a crease where the spar flange edge is located under the skin. Best way to describe this is to take it slow, and work up and down the entire section of the rolled skin. Then, when you think you have it just about right, keep bending it and rolling it with your hand some more so that the skins overlap each other, and only mnimal pressure is required to push the two skins together so that the rivet holes line up. I think that the whole trick to this is finding the sweet spot on the skin where you can apply pressure to keep bending it closer toward the mid section without risking
creasing the skin where it joins the spar flange.

Other than that, you pretty much just have to do it to understand how it needs to work.

-Roll only one section at a time. Yes it takes a bit longer to do this, but it is easier to roll smaller sections at a time.

-  I decided to use a smaller diameter piece of water pipe for the bottom skin, adn a larger diameter bar for the outer skin. I do like how this worked out. My outside diamters were 3/4 " for the inside skin (bottom), and 1 1/8 " for the top or outside skin. This seemed to position the top and bottom skins in such a way that allowed them to form better as you close each one up by hand.

-  I used gorilla tape to roll the edges. Be warned - it will remove the primer on your leading edge - very strong stuff that gorilla tape.

Next pic is about ready to flip the skin over adn roll the bottom mid section of the right elevator.

 The bar gets positioned against the skin so that the skin overlaps the bar by about half the diameter of the bar, or a bout half way across the bar for short :) Then you flip it over so the bar is on the bottom, attach some locking pliers to both ends, and crank away formly and consistently.

The only other thing to comment about is the length of the bars to use. This will be different for the rudder and the elevators, but about 20-22 inches seems plenty long enough to handle any of the control surfaces that need to be rolled. You need to have just enough bar hanging over the exposed cutouts where the rod end bearings are installed, but not so much that it extends beyond the other side of the cutout.

Here is the top section, which is the easiest to put together. I recommend doing this section first to give you an idea of what it will take to do the other sections.

And another important pic to illustrate the fact that the more help you have to perform this step, the easier it is to get it done. You mainly need at least one peson to hold down the skin on the back side becaue you need to move the taped bar assembly far enough forward to be able to attach the locking pliers to the bar to get a good roll. I found that I needed to start the roll, and then reposition the pliers again to roll it just a bit more. If nobody is holding the part down, the heavy bar will flip the whole thing right of the table and you will calling Vans to order more parts. My son Adam was gracious enough to help me with this.

And after both sides are rolled - the center and bottom sections are almost together. The remaining hand forming will close the gaps that you see and align the rivet holes so they can be clecoed together.

This next pic shows what happened to my primer when the tape was removed. Also shows that the edges were still a bit over rolled.

444 hours-Final Trim tab work

Yesterday I performed the bend to the bottom forward skin of the trim tab which is required in order to clear the bottom skin of the elevator, the shop heads of the bottom of the rear elevator spar, and the rear spar itself. As the trim tab moves down there must be enough clearance to prevent the trim tab from binding in these surfaces. There are not many posts or information about how to perform this bend, but one thing is for certain, you do not want to crease the skin so sharply that you risk cracking it, and you do not want to bend it too close to the rivet line either.

SO I came up with the plan to use a piece of 3/16 inch piano wire that I had laying around. I use it for landing gear legs on RC models. The wire was long enough to extend beyond both edges of the trim tab. I set the trim tab in between two pieces of wood so that I could make a recess for the control horn on the bottom, and then I clamped the piano wire up against the trim tab spar web and the bottom trim tab skin. The wire gave me a bit of a radius from which the skin could bend around so that the bend would not be too sharp.

Once everything was clamped down I simply lifted the rear end of the trim tab, keeping the leading edge as flat on the boards as possible,  and bent the leading edge of the bottom skin just enough to ensure that it would clear everything. Came out not the greatest but good enough for me.

The above pic kind of gives you the clue as to why you need to bend the bottom skin. Eventually it will come into contact with the bottom of the elevator and the rear spar. The only question is how much of a bend is needed? This is largely trial and error here and Van's offers absolutely no information about this whatsoever in the plans, except for the picture of the bend and a note that says to bend it.

I also drilled out and reset the two flush rivets holding the corner of the rear spar adn the E705 end rib. They did not set very flush the first time. I may have applied too much primer in the countersunk holes in the rear spar, or perhaps I did not countersink them enough, Once I drilled them out, I countersunk the holes a bit more and then reset two new rivets. The new ones turned out mucho better. You can just see the heads on the right side of the above pic, along the vertical spar web on the end of the spar.

If it bends too far down, the control horn of the trim tab will contact the bottom skin of the elevator, so you know that allowing the trim tab to rotate down that much is going to be too far. The reality is that Van's indicates that the range of motion for the trim tab is supposed to be 25 30 degrees. However, there are  many posts on VAF that confirm that the actual range of the electric trim servo is well short of this mark both up and down. Apparently Van's has even provided clarification, as well as others that have completed their airplanes adn ahve been flying them for quite some time now, that you don't need that much travel for the normal operation of the aircraft. Using my digital level, I determined that my up travel is about 25 degrees, and the down travel is about 19-20 degrees.

This next pic shows the down travel allowed after the bend was completed at the point where the bottom skin contacts the rear spar. This is way more than 30 degrees.

Tonight I decided to install the trim servo, adjust the threaded rod for "level" trim, and then ran the servo through its range of motion to check for clearance of the rod and clevis assemblies with the elevator skin. I found it interesting that running it through its full up and full down range did not really cause much interference with the exit hole on the bottom of the elevator skin. I will still need to do some trimming but not very much. Others have had to trim away quite a bit of material to allow the free travel of the rod without digging into the elevator skin for some reason, but I am not seeing the need. The clearances are very small, but they are sufficient I think.

First pics are with trim tab full up, then full down, and then in level position. Remember that the elevator is turned upside down during all this, so up is down and down is up! I also show my magic trick for connecting the servo wires to the 9 volt battery and running the supplied switch to move the servo. Quite the balancing act....

BTW, the stop nuts on both ends of the clevis require a 1/4 inch wrench to secure and hold them in place while you screw the clevis in or out as needed to set the level position of the trim tab. This can also be fine tuned after you start flying if you determine that the original level position is giving you something other than true level trim of the elevator in flight.

Next pic shows that the rod is just barely contacting the elevator skin on the edge of the exit hole. Maybe 1/8 inch or 1/4 inch more clearance will be sufficient. Clevis on the control horn of the trim tab is very close to the elevator skin, but it still clears.

And now for the down pics

The above pic shows several things. Note how the push rod still favors the right side of the exit hole duw to the misalignment of the control horn with the center of the precut exit hole in the elevator skin. See my extensive previous posts about my concerns with this. Now that the trim tab is fitted and hinged to the elevator, and the trim servo is installed, I am satisfied that any stress on the trim tab servo is minimal. It was only offset about 3/32 inches anyway, and there seems to be enough "give" in the assembly to the point that this is not a concern. Also notice how the clevis on the control horn strongly favors one side of the horn. This is actually drawn in the plans from Van's, and shows the same installation picture with one side of the clevis placed firmly up against one side of the clevis, with a sizable gap appearing on the other side. I guess this is the way it is supposed to be.

And finally some pics of the trim tab servo all wired up with the switch and the position indicator that was supplie with the servo.

And finally back to level position....

Tomorrow I prep the leading edges for primer and then start the rolling process.....