Template for Measuring the 6 Degree Bend Angle

Using a protractor, measured a 6 degree angle on a piece of card board. After bending the ends of both angles, used this to verify if they were at 6 degrees per the plans. You have to pay attention to the plans here, because the angle is based on the forward portion of the 1/8 inch thick angle. I am learning that you must study every detail of the plans, including the origin and termination points of every line in the drawing.

Bending HS 810 and HS 814 Angle Support Brackets for the HS

One of two angle support brackets mashed between the two wood form blocks in my vise, with the ends to be bent sticking out. Can't see it here too well but the block on the back side has the 1/8th inch radius on the corner, per the plans. a 6 degree bend is required, and this needs to be accurate so that both sides of the front spar will have the correct angle for the ribs and the skins. All it takes is a rubber mallet applied squarely at the root of the aluminum to start the bend. It only took a few wacks to get it bent as far as it needed to go. Much easier than I thought it was going to be. How did I know when I reached the 6 degree angle you might ask. Read on for the answer.....
Oh, and thanks to my buddy Ron Duren for reminding me to make the bends in the right direction. It is very easy to make a mistake if you do not think everything through at least twice before actually doing it.

Step Drilling to final Mounting Hole size in Center Hinge Bearing

The drill bits I used to increase the size of the holes in the center hinge assembly

Enlargening Center Hinge Bearing Sub Assembly Nounting Holes

Another shot of the center hinge assembly - this time attempting to enlarge the holes from 1/8inch to 10/32 per the plans. These are the mountinh holes that will be secured to the rear spar with bolts instead of rivets. This was a pain in the ass - I had to use about 5 different drill bit sizes since this hole goes through 3 different layers of material - one steel, one thick aluminum, and one thin aluminum sheet. Note the huge burr that I will need to remove on the lower left hole. I will do this with a file or dremel tool to clean up all the holes. Also note the different colored clecoes. The darker copper ones are for 1/8 inch holes,and the gold ones are for 3/16th inch holes. These worked fine for holding the hinge assembly in place as I enlarged each hole. The drill its kept binding in the metal, so I finally had to put 3 in one light oil on the bits to alow them to keep cutting the metal. What a major pain this was.

Pneumatic Squeezer - I call mine BIG BERTHA

Here is the $700.00 beast that takes rivets and mashes them down like they were grapes, with no effort on my part except to activate a trigger that drives a ram. This is a pneumatic squeezer that can be used to squeeze rivets that are within a few inches of an edge. It is a bit bulky and heavy, and you need to ensure that the work is securely clamped to immovable objects. You put different sets ior dyes n the ends of the black jaws depending on if you are riveting or dimpling the metal. The ram is adjustable and screws in or out to adjust for the proper length of travel. It delivers about 3000 psi,so you don't want to get your fingers caught in this when it activates. Note the air hose attached to the other end. My compressor is set to 90 PSI,so this tool takes that air pressure and bumps it up to 3000 psi in the blink of an eye - impressive!

Cleaveland Tools All-in-One Rivet Gage - very handy tool!

Another really bad pic of a special gauge that I ordered from Cleveland Tools - it has 3 measurements, the size or diameter of the shop head, the height or depth of the shop head, and the height of the remaining rivet shat that is required after it is inserted into the work, to ensure that that rivet is long enough to form a proper shop head. Very handy tool once you understand how to use it.

Shop Head of the AN470AD4-6 Rivets - First Sub assembly complete!

And the other side of the assembly showing the shop head, or the stem of the rivet that has been smashed down, forming the opposite side of the rivet. These have to meet specific thickness and depth measurements, and so using the correct rivet is very important. I have GOT to get me a camera with a manual focus, or fiure out how to disable the auto focus on this one!

Used the Pneumatic Squeezer to set these - Rivets number 1 through 6 are done!

Another blurry pic of all 6 dome headed rivets secured in place - the assembly came out pretty nice looking, if I do say so myself.

Getting ready to drive my first rivets!

Ready to Rivet - the same center hinge and bearing assembly, clamped tightly to the work bench with some 1x2 wood blocks to prevent damaging the powder coat finnish on the hinges. One rivet has been inserted - the plans calle for a -5 size rivet (won't go into detail about rivet nomenclature and sizing here), but the width of the assembled pieces warranted a slightly longer -6 rivet - so that is what I used.

One tip about this - make sure that there is always at elast one cleco installed on either side of the rivet that you are about to set. This keeps the parts from separating due to too loose of a fit resulting from inadequate clamping.

My first fabricated tool! Radius Gauges for Checking Bend Radius

Living proof that I do not like cheap digital cameras very much. This is a bit blurry, but shows two different gauges that I made out of scrap aluminum sheet that Van's provides in the kit. They are used to ensure that the wood form blockes that are used to bend the ends of the aluminum support angle brackets on the front spar of the HS. This is thick aluminum, and you just can't take a piece of wood with a sharp edge on it and start bending the metal - it will fatigue and crack if not bent with a proper radius in the bend. The plans called for a minimum bend radius of 1/8 inch. A trick I learned from one of the sheet metal books I read was to take the scrap metal,drill a 1/4 inch hole in it, and then cut away the metal. leaving a 1/8 inch radius. The gauge can then be placed on two sides of the wood block, which can be sanded to the correct contour for radius needed for the bend.

NAPA Primer and Metal Cleaning Products used by lots of plane builders

Pic of the NAPA prime and surface cleaner that I purchased for the small jobs. Need to use a respirator with this stuff - self etching primer contains an acid that roughs of the surface of he metal, allowing the primer to adhere to bare metal. The process involves sparying the part with the surface cleaner, wiping it dry, then air blowing it dry, then applying the primer. Takes about 15 minutes to dry to the point that you can handle the part.

First 7220 Self Etching NAPA Primer sprayed on HS Center Bearing

A bad pic of the center bearing hanging up on my painting booth hanger (a strand of aluminum wire that I removed from the garage when I wired in a new circuit for the high powered tools to keep them separate from the lights.) It is long enough to string across the garage by attaching it to the shelf brackets on one side and another shelf bracket on the opposite side of the garage. Although hard to see - it has been sprayed with the primer, and the center part has been masked over with frog tape. It is hanging from another piece of copper wire - remnant from the new electrical circuit mentioned previously. This works pretty well for me as a painting platform. I need to get some more flood lamps to add much needed light.

HS Center Hinge with Center Elevator Bearing in place

This is the center hinge bracket with the bearing assembly clecoed inbetween the brackets. Holes were match drilled through the bearing plate, which was primed with NAPA 7220 Self etching primer, after masking the center on both sides to prevent the primer from messing up the bearing. This bearing receives a bolt that connects the control horms of the two elevators - the things that make the plane go up and down, and do loops, and other fun stuff! This is also the first actual subassembly that gets riveted together.

Middle Hinge on one side of HS - Marking Top/Bottom/Left/RIght

Mid-point hinge - if you click on the photo to enlarge it you will see some writing - RTR and RTL - stands for Right side, top, left hinge, nad Right Side top, right hinge. When you drill holes in things it is very important to ensure that the holes will match up again after you disassemble everything and prime it. You get very good at labeling things so they don't get mixed up.

Match Drilling and Fitting HS Hinges to Rear Spar

Outside elevator hing clecoed to the rear horizontal spar. Following are a series of photos as I continue to move forward on the build. Lots of hole drilling involved here.

Class Partner Gets to Keep the Prize

This was my partner in the class. He had started working on his private license many years ago, but like many others, he ran out of money after soloing. He told me that the next time he starts to work on it he is going to finish it all the way. It was very interesting to see that several people in the class were not even rated pilots (yet)!
As much as I wanted to take home the completed project, I felt that it would be better off remaining in the possession of someone that is still trying to realize the dream of aviation, even if it means having a bunch of riveted metal parts stuffed out of sight in the corner of a garage for a while. Perhaps one day it might just be responsible for the creation of one more pilot, or even better yet, another airplane builder! I wish him well in his pursuit of flight.

EAA Sheet Metal Sport Air Class Practice Kit

Here is the project that we built in the workshop. The inspection panel on the right has 3 screws that are secured with 3 nutplates that are riveted to the underside of the skin. The trim tab on the bottom is hinged with piano wire.

HS Rear Spar Halves Joined at the Center

The center joint of the spar. The edges of each bar needed to be smoothed and trimmed to fit inside the spar channel. This takes time to do it properly. All the holes had to be final drilled to the correct size.

HS Reinforcing Bars Clecoed to Rear Spar

Shows the reinforcing bars on the inside of the rear spar channel. These are the bars that join the two spar halves together. These will be riveted in place once the parts are drilled and primed. I am still amazed that after everything is finished, and all the small, thin pieces of aluminum are put together, that they will be able to withstand up to 6.5 Gs!

HS Rear Spar coming together!

The 2 halves of the rear spar clecoed together. The blue color is from the vinyl protective film that is applied over the metal at the factory to repvent dings and scratches. This stuff stays on until its time to dimple and rivet everything together.

Better watch what I am doing here!

Smile! - yes I am finally having fun building my own airplane.

10-6-09 It begins.......Hobbs meter at 5.0 hours

Yours truly with air drill in hand. It all starts with work on the rear spar of the horizontal stabilizer. There are two pieces that are joined together. Total length of the HS will be just over 8 feet. Oh, a note about the "Hobbs" meter. For those that are not very airplane savvy - this is a clock or meter in an airplane that usually runs by using engine oil pressure after the engine is started. I shows how much flight time has elapsed. The hobbs meter I refer to here will "run" while I am actively building the airplane. The time I spend building the airplane can also be applied to hours required for a full blown Airframe and Powerplant Mechanics license, should I choose to do that later on down the road.

Finally getting started!!

So what has happened since my last post?

• Attended a 2 day EAA Sport Air Sheet Metal workshop
• Went to my buddy Ron's house to see his workshop and almost completed empennage of his RV7.
• Spent hours researching primer on the Van's Air Force (VAF) website
• Made my decision to use self etching primer, instead of alodine, at least for the internal priming
• Repaired one of my work benches to correct a bow in the table top
• Officially started working on the horizontal stabilizer on 10-6-2009 - 3 hours last night and 2 hours tonght for a total hobbs time of 5 hours so far.

Details from the above events follow:
For the sheet metal class we built a section resembling an elevator, complete with an inspecton panel and a trim tab. I will upload pics of the fnished project, but I need to pull them off of my cell phone memory first. We had to work in two-person teams, and so only one person got to take the project home with them. I let my partner keep the project, because he had not yet started on a plane yet, and he needed something to allow him to keep dreaming about it. I knew I had the real thing waiting for me at home, so I was OK with giving the project piece to him. The only complaint I had about the class was the time constraint to finish the project. We had to work extremely fast as a team in order to finish it on time.
Seeing Ron's empennage was also a huge plus for me. He showed me his tail pieces, showed me how his workshop is set up, and talked to me about some things to watch out for in the plans. He was finishing up the left elevator, which also contains the trim tab. Ron also attended the workshop that I was at, except he was in the composite class, working with fiberglass and resin, which you need to know how to do to make landing gear fairings and a host of other things.
Primer wars......alodine, acid etch, epoxy-based, self etching, or nothing at all? Those are the choices pretty much. I talked to a rep from Sherwin Wiliams - he even sent me some DVDs, one of which was an entire paint process from a Gulfstream facility in Houston, TX. They showed how they strip, prepare, apply corrosion treatment, prime, and paint a Cessna Citation - what a process! I decided on self etching primer instead of alodine and epoxy primer after finding a post on VAF from a guy that had made a test panel with about 7 different types of primer solutions, including self etching primer. The main issue about this is if the self etching primer really acts as a good anti-corrosion barrier for the metal, with some arguing that the primer actually soaks up moisture instead of repelling it. The guy with the test panel was an employee of a paint company who took the panel to various trade shows, and then finally set it outside in the elements where it was rained and snowed on for about 8 years. The result - all of the primed solutions, including the self etching primer, had stood up well. This was the information I was looking for. So I bought a quart container of NAPA TE504 self etching primer and a gallon of the TER 514 catalyst/activator (not the same as the NAPA 7220 spray can stuff- the stuff I bought is the good expensive stuff that must be mixed and sprayed from a gun). Just to give you an idea - 1 QUART of the primer and 1 GALLON of the Activator set me back about $200.00. Not cheap for sure......
The first of the two work benches I had built unfortunately ended up with a small bow in the table top as a result of bad wood that I used for the frame. Several shims and repositioned cross braces later, the table top is now relatively level - so that problem is resolved.
It's official! October 6, 2009, I actually started on the rear spar of the horizontal stabilizer. This involved a lot of hole drilling and partial fabrication of of some thick reinforcing bars. Priming parts and riveting them together is just around the corner... Pics and more info in the next post.