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TailCone

The Tailcone is from the back of the baggage compartment to the end of the plane. It is the part that the tail feathers (HS and VS) are mounted.
 
Part Started: 5/1/2011
Part finished: 6/28/2011
Time : 109.25 (16.75 add-ons) + 16hr Tailcone Assembly
Changes from plans:
  • Added doubler in bottom of tail for antenna.(NAV) (.5 hr)
  • Added doubler on top middle for antenna.(ELT or COMM) (.5hr)
  • Added Rudder cable farrings (1.75 hr, $15 from AveryTools)
  • Installed Static System (1.5 hr SafeAir1 $80 from AveryTools, 1/4 Adel Clamps (3) from AircraftSpruce $1.12)
  • Added rear NACA Vents (12 hr $15 from Vans)

 

Mounting the HS and VS

posted Jun 26, 2011, 1:37 PM by Bill Thomasson

I followed the instructions from Vans on mounting the HS and VS. Nowhere in the directions does it tell you to check for square, except forward/backwards square of the HS to the tailcone.
 
HS and VS go on quickly, and make it really look like a airplane.
 
I did make sure I had the tailcone sitting square on the sawhorses, But then did not check to make sure the HS or VS was also level, just followed the directions.
 
After I finished all the bolts, I thought "I hope it is square", and then made the mistake of checking.
You can't see it well in this picture, but I put a crosshair laser level on pointed at the tail with the HS exactly level, the laser hitting all of the rivets.  Unfortuantely the VS did not line up on the vertical laser line.
This shows where it is falling at the top of the VS when it is centered.  It is about 3/8" off.  This appears to be caused just by different holes being 1/32 or 1/64 off, but over 4-5 feet this causes a bigger change.  The out-of-alignment is not noticeable at all without a laser line, but if I ever build another plane, before match drilling the VS I would make sure that it is vertical with a laser level, or by measuring from HS tip to VS tip and other HS tip to VS tip and making sure they are the same.  I have been told by other builders to not worry about it that it should not have any adverse flight characteristics.  But if you have not mounted yours yet, make sure it is vertical before final drilling the holes.  I think because of the small amounts we are talking about if it had been done before the holes were final drilled, the final drilling could have fixed most if not all of the alignment.

Tail Cone Completed

posted Jun 26, 2011, 1:29 PM by Bill Thomasson

I had the tailcone mostly completed for several weeks, but had a few outstanding tasks, the hardest one was the 12 rivets that I could not complete by myself.  Today I took Scott Franklin and his kids Matt and Chris for a ride in N7124E.  Afterwards they came over to play.  While they were over Scott volunteered  to help me with the last rivets that I could not reach.  I backriveted most of them, but because of my static system mounts 3 could not be backriveted, so Scott got to run the rivet gun.
 
The tailcone is complete, still working on the trim system setup.  Made all of the brackets for the trim system last night, but need to prime and rivet them together. 
 

Rudder cable Fairings

posted Jun 24, 2011, 11:47 AM by Bill Thomasson   [ updated Apr 30, 2012, 11:18 AM ]

Don't do this now.  You have to string the rudder cables before adding the fairings.  See Rudder pedals
 
My plane will probably be on the ramp for it's first few years of life, unfortunately as I don't have the spare cash to pay for a $400 T-hanger and the payments I will be making on the engine.  The open slits where the rudder cables exited looked like an invitation for water and bugs to climb in.  The fairings also give a more finished look (AveryTools $14 for set).
 
I have seen some rudder fairings riveted to the outside of the skin, and others to the inside.  I am hoping that with a little epoxy fethering in the edge of the skin that the inside mounted ones will look better.  This involved cutting a larger hole where the exit hole was, and then riveting it in place.
I did this when building the tailcone, thinking it would be easier to do before riveting the top deck on.  If I were to do this again I would definately wait until I had mounted the rudder and could confirm exactly where it should line up. The access plates still provide enough room to get a bucking bar on the inside.  Hopefully when I mount my rudder I will not have to cut these out and reposition them.
 

Static Ports / System

posted Jun 24, 2011, 11:26 AM by Bill Thomasson

I purchased the SafeAir1 Static ports and lines from AveryTools ($117.50).  These ports and connectors just looked like a more finished and less jurry rigged solution.  I had also read posts about the tubes cracking over time where they were mounted to the pop-rivets in Van's static system.  I want a low maintanance high reliability plane, so I decided to use the SafeAir1 kit.  To it I had to add 3 adel clamps (1/4 inch) from Aircraft Spruce ($.23 each).  I purchased a variety of adel clamps from Spruce as I know I will need them for many different mounts as this kit progresses.
 
I decided to both rivet and Proseal the ports in.  I read some reports of ports that were just riveted in as not passing static checks because the suction cup tester covered the rivets and although the port was not leaking, the rivets were, causing the test to fail.  The though of just prosealing them, with that little contact area, and the large leverage arm of the port, connecter and tube possibly vibrating the proseal I did not like either, so I did both.
 
I added a bracket (with nutplate) that I made out of some leftover J-stiffener to hold the T-connector that will route the static line to the front of the plane, and 2 more nutplates for the adel clamps to hold the crossover line connecting the 2 static ports.
I am very happy with how the static system is installed (so far at least).  The T-connector (right side even with logeron) is setup so that at least the initial part of the run up front will go down the logeron.

Riveting the TailCone

posted Jun 24, 2011, 11:02 AM by Bill Thomasson

I followed Jessen's method of backriveting the entire tailcone.  Another site I got tips for this was Mouser's.  This went very quickly for 95% of the rivets.  The first thing to do is when cleco'ing the tailcone together, put all of the Cleco's on the INSIDE instead of outside.  This keeps them from getting bent, and keeps them out of the way.  Then follow Van's direction on what to rivet when.  The exception to this was I followed Mouser in backriveting the F-1055 stiffeners onto the skins before putting the skins on the tail.  To backrivet it you just end up flipping the tailcone back and forth on it's side to put 13 rivets (Avery backrivet plate) at a time, then flip it back to get those rivets sitting nicely on the plate, go inside or reach over and rivet them.  I was able to do all but 10 rivets total on the bottom and sides by myself. 
 Then had Dee (my wife) hold a large bucking bar to backrivet the last 10.
A few of the rivets for the ribs were under the edge of the J-Stiffeners, so you could not hit them directly with the backrivet gun.  I ended up filling down a chisle to work as an extension.
I would then put the backrivet gun as close to the rivet as I could on top of the chisle, with the chisle on the rivet. As you are not getting all the force of the gun on the rivet, you have to turn the pressure up some on the gun.
 
After doing the deck, and installing the static ports and lines, I also did the topskin backriveting it by myself.  I was able to do all but 13 rivets myself, with Dee providing support for the last 13.  The top being curved took a lot more time to make sure each rivet was flat on the plate before riveting.
Many times I used the wedges that were cutout of the trim tab clamps to put under part of the tailcone to get it to sit flat on the backrivet plate.
 
 

Help arrives

posted Jun 24, 2011, 10:55 AM by Bill Thomasson

Well my parents were in town for a couple days, so do I take the to Stone Mountain or somewhere else.  No, I set them too work in the basement.  Wonder if they will ever visit again before I am done :)
Dad helping remove clecos so that we can deburr the tail.
Mom starts by supervising, but ....
Gets dragged into deburring skin holes.
When the skins are all done, dad is put to work dimpling the J-Stiffeners.
 

The NACA Vent disaster and repair

posted Jun 15, 2011, 4:48 PM by Bill Thomasson   [ updated Jun 24, 2011, 12:01 PM ]

I must have been having a really bad day when I started my rear NACA Vents.  I am installing rear vents that will be connected to an overhead console providing overhead air similar to what airliners have.  This is not part of the "Standard" RV plans, but is a modification that many builders make.  This being the first major modification that I have made, I read many other builder blogs and looked at lots of pictures before deciding to proceed.  I thought I had a plan, and I followed it, but I had not evidently thought it through enough or paid enough attention to detail, it was going soooo smoothly I was very happy as I completed my first rough cut and stood back and looked over it as I was about to start filling it to the final shape.
First I made a cardboard template of the cutout from a cerial box and the back side of the NACA vent.  I was very proud of my work in getting it to exactly match both the inside and outside of the vent's cutout.  Now an someone that has seen, or installed a NACA vent before will see not one, but 2 problems with this picture.  First the template is on backwards, the narrow part should be at the front, the wider part at the back.  I say wider part, because although the vent opening is that shape, the skin is only supposed to be cut back to the widest part of the vent.  So when you first cut it backwards, and then cut too much out this is what you get.(after a lot of yelling and screeming)
After putting the vent up behind it and seeing that the flange of the vent covered the areas that had been removed, I felt it was probably salvageable. (At this point it had still not dawned on me that I should have stopped the cut at the widest part, and was feeling very proud at how the back curve came out).  I posted on VansAirforce.com to get other builders oppinions as to if I should just fill the missing skin with epoxy, or if I should cut out little slivers of aluminum to fill in the missing pieces.  It was then that I realized that I had also cut way too much in the back of the vent..... A lot more yelling and screeming, and possibly some crying.  Luckly after a sleepless night, I had several very helpfull posts, including one person that had done the exact same cutting out of the back side (although not the messup of the reversed vent to start).  Using his repair as a guide, but extending it to cover the front messup as well this is what I did.
 
First I cutout a doubler out of sheet stock that is twice as thick as the side skin. and is wider than the vent.  The hole in this plate is what the original hole should have looked like.
 
I then cut a 1/2 circle and two slivers to match the missing pieces.
I cut them so they would hang over into the vent about 1/16" past the backing plate, then dimpled all parts, riveted the doubler onto the skin, and the back curved piece onto the doubler.  I did not rivet the small slivers on as those rivets are giong to go through the vent itself, but prosealed them onto the backing plate.
 
Because I wanted the rivets (into plastic) to be more structual (although just structual in the sence of holding the slivers on, I also build a thin backing plate for all the rivets that will go behind the plastic, so the rivets sit against aluminum on both sides, sandwiching the plastic vent.
I then prosealed and riveted the vent (and slivers) on.
I then mixed up some epoxy and spread a thin coat over the entire area.
 Then waited for it to dry, and then sanded it all flush. (lots of sanding... should have put a thinner coat on).
 
I still need to do a little more sanding and filling, but I am calling it complete for now. My lesson learned, look at the big picutre before making any cuts, especially if you are "off plans". Left side vent and repair 14 hr. Right side vent done right the first time 45 min.
Left Side
Right Side

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