Horizontal Stabilizer mistake repair...AGAIN

RV14 Build September 12

Horizontal Stabilizer

The repair that I thought worked...well didn't. The two holes that I drilled are 3/32 different on there center point. I have no idea how I was so far off. Oh well, plan B it is. Drill out the rear spar, flip it and install it in the correct orientation to the front spar. Then I can use the front spar mounting holes that Vans Drilled.

Time to start drilling rivets!

Got the rear spar out without any damage!

Using a punch to remove the old rivets from the spar since its thick.

Its nice that I can use the squeezer to install all these at least

Almost have the top done.

Top is done, just flip and repeat

All the pop rivets are back in and now have to squeeze the last rivets on the inner ribs.

Done and Done! Call the Horizontal Stabilizer section complete....Finally.

Horizontal Stabilizer 3.0 Hours

Horisontal Stabilizer Mistake Repair

RV14 Build August 2

Horizontal Stabilizer

Just as a recap. When I first assembled the HS the primer I used wasn't mixed correctly and I was concerned it wasn't going to cure and cause issues down the line. So I drilled everything apart and stripped the primer off and re-primed. Since I had assembled everything once I did it again mostly from memory and this is where I got myself into trouble. The front and rear spars have an Up and Down orientation and depending on how you look at it I flipped 1 of them when installing them. I thought I would be able to modify the rear spar to work, but the rivet holes to mount to the brackets are on an angle and not straight 90 degrees to the fuselage so the orientation of the rear became the driver. This meant I needed to drill out the rear spar or located and drill new mounting holes in the front spar.

I decided to drill the front spar. First I ordered the front spar doubler and match drilled the mounting holes into it. The red arrows show the holes that need to be drilled.

After I match drilled the double i bolted it on using the Vertical stab mounting bolt holes for orientation and then used a drill bit guide block to drill straight.

Here goes nothing!

Repeating the process on the other side.

I think I managed to pull this one off! I send pictures to Vans and am still waiting on there reply as to if this is ok! If not I will be building a new Horizontal Stab.....yikes! If they say its all good then this is officially done!

Horizontal Stabilizer Hours 3.0

Horizontal Stabilizer Mistake fix Idea July 20

RV14 Build July 20

Horizontal Stabilizer

So a quick reminder of what I did here. Basically the front and rear spar have an up and down and I flipped 1 of them, Im choosing to say that I flipped the front one. I thought I had 3 different ways to fix it, but the rear spar support bars run at an angle, so the spar is not symmetrical and the rear down has to be the down, and this knocks out one of my potential fixes.

What my plan is now. Relocate the mounting holes for the front spar and drill them exactly. I measured the hole edge to the bottom of the spar, then measured the whole spar. I figure what Im trying to do is mirror the hole location so I took the distance of the bottom edge hole to lower edge of the spar and added the radius to it, this gave me the distance from the center of the hole to the bottom edge. In theory since the holes are going to be mirrored its the same distance from the top edge to the center of the whole I want to drill. So if i double that distance and subtract it from the total spar width I would be left with the distance from the center of 1 hole to the center of the other, then I added the radius again and that should be the distance from the top of the hole I have to the center of the one i need to drill. I cross checked that location with edge of hole to bottom of spar distance mirrored on the top and everything was in the same place. So i feel comfortable I found it vertically. Luckily for me there is a rivet line and the edge of the rivets corresponds to the center of the hole I want to drill so locating the hole horizontally was a little easier. Drill the 1 hole and then use the bulkhead as a template for the second hole by match drilling.

As I was writing this I had another idea, buy the doubler cut it to size flips its orientation so up is down and use the 4 vertical stabilizer bolts holes to mount the doubler to the spar and then use the holes in the double to locate the holes in the spar and match drill!! Way easier. 

Horizontal Stabilizer April 24

April 24

Horizontal Stabilizer 

Fixing and Finding mistakes today. First a few rivets on the front spar that I noticed weren't set well. Researching I found that If at .002" shim can slide behind the rivet head and touch the shank it needs to be fixed.

First I tried to re-buck the rivet but that didn't work well so I decided to drill them out and and put new ones in.

I had to remove a few rivets from the skin to be able to get my hand behind the spar with the bucking bar, but I made it work.

I was able to use the lightening holes to get in with the bucking bar and re-hit the rivets in the skin that weren't set well. Then I noticed it. The biggest mistake to date.

The front and rear spar have an top and bottom, In my rushing to "catch up" from my previous mistake with the primer I didn't read the directions well and just as I was finishing the last few rivets on the skin I realized the orientation of one of them is wrong. The arrow pointing to the notch in the rear spar should be on the bottom of the HS, the circles around the unriveted rivets should be on the top of the HS, and the arrows pointing to the 2 holes in the web of the front spar next the the 9 rivet pattern should be on the bottom and they are on the top. 

I emailed vans about this, from the way I see it I can cut the rear spar and flip the notch, this will also require me to dimple the rivet holes in the skin and un-dimple the corresponding holes on the other side. basically making the top the bottom.

Option 2. Drill out the rear spar, flip it, and move the holes in the skin as described above.

Options 3. Try to locate the position of the mounting holes on the front spar and drill them.

Vans recommends I go with option 1. I think I might try option 3 first after I build the rear fuselage and use the mounting brackets as a guide as well as trying to measure and locate the holes. If this doesn't work I can always go with options 1 after. For now the HS is done and set aside.

Horizontal Stabilizer 1.5 Hours

Horizontal Stabilizer April 18 & 19

April 18 & 19

Horizontal Stabilizer

One day Im gonna realize how much time it takes to get things done! I set the HS skins into the jigs that I made and then riveted the nose ribs that I already installed in the skins to the front spar and then started working on the riveting the skins to the spar and ribs.

Once I started riveting the skins I noticed that I had the skins on the wrong sides! There is a line of rivet holes that i didn't countersink so a plastic fairing could be screwed into them in the future. Since I had the non counter sunk skins and ribs flipped from each other I decided to use the squeezer and flatten the countersink in the ribs to match the skin that was on each side.

This seemed to work fine, I just hope it didn't create micro-cracks in the rivet hole that will crack later in the future under the vibrations of a flying aircraft!

Now that I got that mistake "fixed" I am moving forward and riveting the skin. I started with the skins in the cradles on the floor and sat in my chair all hunched over working on shooting the rivets. This is less than ideal, my back was not happy about it.  i started riveting from the leading edge back, mostly so that the opening would stay large longer for me to get my arm into the part with the bucking bar.

After finishing 1 side of the HS I moved the part horizontal on my bench and used cardboard boxed to hold it up. This was a WAY better position to rivet in for my back. It did initially lead to more sloppy technique with my bucking bar causing it to dig into the primer a bit. Once I adjusted I was able to be more careful, the work flow also seemed to go faster in the orientation.

Done for the day, what I thought would take me 5 hours to rivet is now on hour 9 and I have 1 side of 1 half to rivet still. Mental note for the wings, they are going to take forever to rivet!

Horizontal Stabilizer 9.0 Hours

Horizontal Stabilizer April 17

April 17

Horizontal Stabilizer

Riveted the front and rear spar back together today, finally got back to where I was before I realized the paint job was off. Total time to fix that mistake on the Horizontal Stab 19.5 Hours! Not counting having to rebuild the rudder still, Oh well. At least Im making progress again!

One nice thing is I think I finally figured out this squeezer! I have to squeeze the rivets in a 2 step process. I set the tool to the recommended gap and squeeze everything of the same size, then come back after adjusting the gap smaller and setting the rivets to the final size. I've also turned the air pressure up from the tank to around 115psi which seems to help too. Its a little disappointing it wont set rivets in 1 go but its nice that I got it works now so Im not hammering all he rivets and risking damaging the parts with poor technique holding my bucking bar.

It is nice how uniformed the squeezer make the shop heads!

Finished the spars and started on new progress! Per the usual I thought this next step would be simple as squeezing the rivets together and the angles proved to make the center section much harder to assemble.

After finishing the center section I attached it ti the front spar along with the other ribs.

I then put the leading edge nose ribs into the skin and riveted. Theses I had to shoot with a gun and bucking bar. It took several attempts to get the most forward set correctly. Its very tight to get a bucking bar on it at the right angle.

All in this was a very productive day at the shop!

Horizontal Stabilizer 7.0 Hours

Horizontal Stabilizer April 16

April 16

Horizontal Stabilizer

Well its been some time but I finally got back to the shop. Yesterday I spend 2 hours cleaning the metal for paint prep and today I primed all the pieces, again, and dimpled all the parts for the CS rivets in the skin.

I really hope that I mixed primer correctly this time! I made 2 batches of 250g of Part A then 18% of that or 45g of Part B and then reduced it with water by 13% of Part a or 33g. I made sure to mix everything super well. The Part A was really thick almost like a paste when I first opened it, so I put my paint mixer in the drill press and let that spin for 10 mins. That seemed to to the trick!

I had emailed the company and asked what color they thought was the easiest to cover with a top coat and they recommended smoke grey for an all around option with not knowing what color topcoat I was going to be using. So Smoke grey it is now instead of the green I was using. The 2 part green color was very close to the CZ Green, but the single part just didn't look right, and after spraying the grey I do like the way it came out.

I am still very impatient when it comes to painting. I tried to be better this time spraying a Fog coat followed by a Wet coat. While I was waiting for the fog coat to tack up I cleaned up the shop and started to get the HS Skins ready for dimpling. This wored well for the 1 side, but then while I was giving the parts time to dry I dimpled everything I had to dimple flipped the parts and sprayed the other side. It was a little too soon and the the paint was stcking to the spray table. I need to spray 1 side and wait a few hours or overnight before I do the other side in the future. I just need to learn patience. Also, still need to get better at spraying in general. I was having issues getting the gun set correctly and was putting down uneven coats of primer.

I don't know why but I dimpled with the blue plastic still on, this was a mistake. I thought about it half what through the second skin and peeled the plastic off. I set a rivet into the dimples and the are definitely deeper from having the plastic between the dimple dies. Hopefully this doesn't cause a problem in the future when I am riveting the pieces together.

Horizontal Stabilizer 7 Hours