Archive for category Preparation
Ailerons Finished (3/17/11)
Posted by Ethan Jacoby in Ailerons, Construction, Tools, Wings on March 17, 2011
2.0 Hours -
My new bucking bars from The Yard arrived yesterday, and I was anxious to “play” with them. The first thing I did was attempt to set the aft-most rivets in the right aileron’s trailing edge. With the new, narrow bucking bar, these were a piece of cake to set. I wish I would have bought this when I started working on the empennage!
I bought two new bucking bars from The Yard. The one on the right is specifically for bucking the aft-most rivets on the ailerons. The one on the right just looked like it would come in handy.
The new bucking bar made setting these rivets a cinch...I wish I would have bought it when I was working on the empennage!
Next, I went to work on the left aileron, repeating everything I did on the right aileron. For details, see my post from March 15th, which details the aileron assembly. Everything went according to plan while riveting. However, my pop-rivet puller started giving me problems. The jaws don’t seem to want to grab the rivet shank…sometimes they grab, sometimes they don’t. It was a hassle, but I managed to set all of the pop-rivets and it’s definitely time to buy a new rivet puller!
All riveting on the left aileron is complete. It looks nice and straight...I'm happy!
Side view of the left aileron.
Once all of the riveting was completed, I bolted on the aileron brackets. The inboard brackets were easy, but the outboard brackets are too narrow for a wrench. To tighten these, I had to hold the bolt head with a set of pliers, and slowly tighten the nut with the smallest wrench I could find. Eventually, all of the bolts were tightened and torqued. However, I didn’t put torque seal on yet. I was getting tired and hungry and decided I would recheck the torque another day and apply inspection lacquer at that time.
The inboard aileron brackets are attached with three bolts.
Side view of the inboard bracket.
The outboard bracket attaches with two bolts. Due to the narrow space between the bracket walls, these brackets weren't the easiest to install and torque.
The ailerons are now completely finished. Next up is the flaps. After that, nothing is left except installing push rods and riveting the outboard bottom skins.
More Countersinking and Wing Prep (12/10/10)
Posted by Ethan Jacoby in Construction, Leading Edges, Main Structure, Panel/Wiring, Spars, Tools, Wings on December 10, 2010
2.3 Hours -
Tonight, I resumed countersinking the left spar. I finished countersinking the bottom of left spar and the leading edge portion of the top of the spar. To do the top, I had to remove the outboard skin. Now, I just have the top/inboard of the left spar and the entire top of the right spar remaining to be countersunk.
Once I finished countersinking for the evening, I cleaned the spars with acetone and sprayed some self-etching primer to cover the exposed aluminum in the countersinks.
After countersinking the main spar, I cleaned it and sprayed some self-etching primer.
Ready for a break from countersinking, I decided to make the ground wire for the stall warner system. This was fairly quick to complete since all I had to do was to cut a 3.5 inch piece of 18 gauge wire, strip both ends, and crimp on terminals. To crimp the terminals, I ended up buying a ratcheting crimper from SteinAir. The dies on the crimper are interchangeable, and I purchased dies for both RBY and BNC terminals.
I bought this ratcheting crimper from SteinAir. It has dies for both RBY and BNC terminals.
Nothing complicated...the stall warner ground wire is a 3.5 inch piece of 18 gauge wire with terminals crimped on each end.
Finally, I started deburring and dimpling the left wing structure. Trying to break up the monotony, I would deburr a rib and a portion of the rear spar, then dimple those sections. Changing tasks like this seems to help me work longer. However, there is still a lot of countersinking, deburring and dimpling left to do in the wings.
Where To Put The Third Wheel (11/27/10)
Posted by Ethan Jacoby in Preparation, Random Stuff on November 27, 2010
Wait...the third wheel is in the wrong place!
I’m getting close to placing an order for my fuselage kit. Throughout the entire planning/building process, I’ve been planning on building an “A” model (nosewheel or tricycle gear). However, I’ve recently started thinking about building a tailwheel model instead (standard gear). There are a few reasons for my nose gear doubts:
- Van designed the plane with a tailwheel. The tricycle gear model came out later. If the plane was designed to be a tailwheel plane, why mess with that design.
- The nose gear, even though it has been redesigned, still looks weak. There is still the occasional report about it failing after hitting only a small bump or digging into a hole. The new gear design seems to have fixed many of these problems, but it is still happening occasionally.
- Related to number 2, the tailwheel allows you to land on many more “unimproved” runways than the nosegear would allow. Tailwheel aircraft are just better at landing on grass, gravel, etc.
Of course, the tailwheel also has its problems, with my main concerns being ground loops and prop strikes. In order to see if my concerns were legitamate, and to get some flying in, I scheduled a tailwheel intro flight in a PA-18 Super Cub based out of ProMark Aviation Services in Burnet, TX (KBMQ). When I arrived at the FBO, I sat down with the CFI, Ken Wittekiend, and we talked about my concerns, and tailwheel flying in general, for about an hour before heading out to the Super Cub. The main points of the discussion were that ground loops aren’t a problem if you use good technique and keep the plane straight at all times, and prop strikes are unlikely except during heavy braking…as I later found out, you really have to push the stick forward hard to get the tailwheel off the ground during the takeoff roll and the nose doesn’t want to dip much lower than level attitude when the stick is forward.
As soon as we took off from Burnet, the controls were handed over to me. I had not flown for close to 2 years, so I immediately did a little over controlling and mild wing rocking…I’ll blame it on flying an airplane with a stick for the first time. However, I quickly returned to level flight, gained some altitude, and then did a few turns to get used to the airplane. After some slow-flight and a few, incredibly mild, power-off stalls, we turned towards Llano, TX (KAQO), where they have a very wide grass strip.
First, we did a low approach, where I just tried to keep the airplane close to the runway and straight. The CFI handled the throttle so all I had to think about was keeping the nose up. Then, we went around and started over. This time, we actually landed, and I was very surprised how much rudder input was needed to keep the plane straight (good thing that was a very wide runway). We did two more landings, with each one getting a little better.
Finally, we headed back to Burnet. The Super Cub isn’t the fastest airplane, but it was fun to do some low and slow sight seeing from about 500 feet. I’ve never actually had to climb to get to pattern altitude, but as we approached Burnet, I did just that. We made the final landing, parked the plane, and talked a bit more about getting an endorsement. I’ll likely finish the endorsement as I decide how to build my airplane. However, I don’t know that the tailwheel fears are justified. If anything, having to use the rudder more makes you a better pilot and I now realize how much a tricycle gear airplane, like a Cessna 172, lets you get away with.
The mains are huge! Too bad the door isn't a bit bigger, at 6'2", this was not an easy plane for me to get in and out of.
Parker Rolo-Flair
Posted by Ethan Jacoby in Preparation, Tools on September 23, 2010
I received my new flaring tool today. Within 5 minutes of opening the Parker Rolo-Flair, I was able to make a much better flare than the ones I had made with the Summit tool.
My new Parker Rolo-Flair. I was able to make a better flare with this, compared to the Summit tool, on my first try.
The Rolo-Flair has two dies that are rotated to the correct tubing diameter and then used to clamp the tube in place. The die surfaces are smooth, not serrated like the Summit tool. The Rolo-Flair also has a positive stop that lets you know exactly how far to insert the tube. When the tool is closed, the stop moves out of the way. With the Rolo-Flair, it was also much easier to tell exactly how far to rotate the cone-shaped flaring head…as soon as the proper depth was reached, resistance increased dramatically. The tool then burnishes the edges when the flaring head is backed out. Without spending much time to prepare my test tubing, I was able to make a nice flare on the first try. But, a picture is worth a thousand words.
Using the Rolo-Flair, there is no scarring on the sides of the tube and the flare is nice and clean.
Flare made with Summit tool: Notice the scarring on the side of the tube...the tube is also distorted into a somewhat oval shape.
Despite my bad pictures, we have a clear winner!
Pitot-Static System
Posted by Ethan Jacoby in Preparation, Wings on May 14, 2010
As I wait for my wing kit to arrive, I’ve been purchasing items that will be needed to complete the wings. My most recent purchase is a Dynon pitot/AOA probe to complete my pitot-static system.
The Dynon pitot/AOA probe.
For the non-aviation geeks, the pitot-static system is a two part system that is used to measure airspeed and altitude. The system itself is very simple, consisting of ports on the outside of the plane which are connected to tubing. The tubing then runs to various instruments. The instruments translate changes in air pressure to useful information.
The pitot tube, mounted under the wing in this case, is used to measure airspeed. The static ports, consisting of two ports on the aft fuselage, are used to measure altitude and help correct the airspeed. Both the pitot and static ports allow outside air to enter the tubing they are attached to. The static ports are out of the slipstream and allow static air to enter. The pitot tube points forward. Air is forced into the tube as a result of the airplanes forward motion. The faster you go, the higher the pressure will be in the pitot system. The tubing for the pitot-static system is routed to various instruments which measure the pressure in the system and convert that to useful information such as airspeed and altitude. It may sound complicated, but it is actually a very simple system.
Van’s supplies aluminum tubing in the kit. This tubing is used to make all the pitot-static lines and the pitot tube. The static ports supplied in the kit are nothing more than a couple pop-rivet heads with tubing glued on to the back. While this works perfectly well, I decided to go another route. I’m using the Safeair1 pitot-static and AOA tubing kits, the Safeair1 pitot mast, the Safeair1 static ports, and a Dynon pitot/AOA tube.
The Safeair1 pitot, static, and AOA tubing is plastic tubing and push-on connectors. I feel this will be much easier to install than aluminum tubing and produce fewer leaks that have to be tracked down and fixed. The Safeair1 static ports are billet aluminum that has been milled to duplicate the shape of the Van’s pop-rivet port. They won’t work any better than the Van’s method, but they just look nicer.
The Safeair1 pitot-static tubing kit contains everything needed for an RV pitot-static system except for the pitot tube.
Safeair1 static ports. Left: tubing connection. Right: outside port.
The Safeair1 AOA kit contains more tubing and fittings for the AOA side of the pitot probe.
The only reason I’m using the Safeair1 pitot mast is because it is specifically made for use in an RV with the Dynon pitot/AOA tube. This alone should make it simple to install. The Dynon pitot/AOA is basically two tubes wrapped up in a very nice package. The upper port is the pitot port, while the lower port is the AOA. The AOA (or Angle of Attack) uses differential pressure between the two ports to measure the wing’s angle of attack (wing chord vs. relative wind). Simply put, it is a type of stall warning. However, AOA can also be used as a tool for landing. Navy pilots fly AOA, not airspeed, when they land on carriers.
The pitot/AOA probe mounts in the Safeair1 pitot mast. However, no instructions for how to do this...time to look up some other builders!
The pitot/AOA probe is simply two tubes angled away from each other and incased in a nice housing.
A Few New Tools for the Wings
Posted by Ethan Jacoby in Preparation, Tools on May 9, 2010
In preparation of the arrival of my wing kit, there are a few things I need to buy. As usual, some of these things happen to be tools.
There are a lot of ribs in the wings, and each rib has three lightening holes cut into it. The edges of all these holes have to be deburred. Until now, the few lightening holes I’ve had to deal with, I’ve just used some emery cloth and ScotchBrite pad for deburring. This method is fine for a couple holes, but it is slow and tedious. So, for the wings, I’m going to use a 2” ScotchBrite wheel attached to a pneumatic die grinder. This will let me deburr the holes the same way I deburr the edges.
Kobalt die grinder with 2" ScotchBrite wheel.
In addition, during wing construction, I’ll encounter aluminum tubing for the first time. This is used for fuel lines and also in parts of the pitot and brake systems. Where ever a connection is made, the tubing has to be flared to 37 degrees. Flairing tools can get very pricey, and I’m only going to need to make 20 or fewer flares for the entire plane. Therefore, I decided to go on the low end and try a flare tool from Summit Racing. At $30, I won’t feel too bad if the results are poor and I have to get one of the more expensive tools to finish.
*EDIT* After a couple of attempts at using this flaring tool, I’m not happy with the results. The flare itself is adequate, but the block holding the tube leaves marks or scars on the tube. In addition, I’ve found that the tool distorts the tube to the point where a sleeve is very difficult to slide into place. I can make it work, but I don’t want to chance this on the fuel system. Therefore, I’m going to call my $30 experiment a failure and order a Parker Rolo-Flair. The Rolo-Flair is significantly more expensive at around $100, but I haven’t heard any complaints about it either.
I'm going to try this less expensive flare tool from Summit Racing. If the results are poor, I'll get a rol-flair.
To bend the tubing without collapsing it, a special bending tool is used. This tool was also purchased from Summit Racing, and should do the job well.
A tubing bender is a pretty simple tool.
Finally, I bought a digital caliper. The caliper I already had uses a dial. This is fine, but if you don’t pay attention, you have no idea how many times the needle spun around before stopping. The digital caliper gives me a reading in inches or mm and seems to be very accurate when compared to the dial caliper. Plus, I had a coupon that took over $20 off the full price.
Digital = Easy to Read; Dial = How many times did the needle go around?
Wing Stand Construction Part 5 (3/25/10)
Posted by Ethan Jacoby in Construction, Preparation, Wings, Workshop on March 28, 2010
1.0 Hours -
The ongoing saga of my wing stand construction continues. I’ve now attached the aluminum angle and associated leveling hardware to two of the wood columns. The mechanism worked great as they were easy to level. However, I’ll wait to complete the other two stands until I’m ready to use them. The reason for this is that our garage floor is so unlevel that I will have to decide where I will build the wings, set up the stands there and not move them from that position. From my initial measurement, the slope of the garage floor may require one end of the stand to be an inch lower than the other end. Once the wing kit arrives, I’ll use the actual spar to make sure the second stands can keep the spar level.
The finished product. As you can see, the leveling system works perfectly.
Still More Wing Stand Construction (3/22/10)
Posted by Ethan Jacoby in Construction, Preparation, Wings, Workshop on March 22, 2010
3.0 Hours -
I’ve been working on my wing stands off and on over the last few days. The more I work on them, the more I think I’m probably going overboard on their design. However, I made my plan and started building them, so I’m sticking to the design.
The concern comes from the threaded rods I’m going to use to hold the aluminum angle where the spar will attach. These rods will allow me to level the angle and, thus, the spar. However, I could also do this simply by drilling a second hole through the angle and using two bolts through the angle/wood column. My system is making it more complicated than it probably needs to be. On the other hand, my garage floor is so unlevel, that the threaded rod may work in my favor if I need to move the wing stands at some point mid-construction.
Concerns aside, I’ve finished the wood portions of all four stands, and I’ve also finished fabricating all of the aluminum parts that will be used for attaching the spars to the stands. My fabricated parts will get the job done, but I’m putting no effort into making them look pretty. Probably a good thing I’m not trying to build the plane from plans!
The wood portions of the wing stands are completely finished.
All the metal components of the wing stands have been and finished. The camera made the rods look bent, but they are not.
This is how the metal components will be assembled on the final stands. The long piece of angle at the top will hold the wing's spar and be attached to the wood column with a 3/8" bolt. The threaded rod will allow me to make fine adjustments on each stand.
A close up of how the rod will attach to the long piece of angle.
A close up of how the rod will attach to the wood column. A 3/8" bolt will go through the hole on the right and through the wood column.
Wing Stand Construction Part 3 (3/17/10)
Posted by Ethan Jacoby in Construction, Preparation, Wings, Workshop on March 17, 2010
1.0 Hours -
More wing stand construction this evening. Two down, two to go. However, I’ve diminished my scrap plywood supply, so construction is at a halt until I make a Lowe’s/Home Depot run.
No pictures since this is the same as in my previous post on the wing stands.
More Wing Stand Construction (3/15/10)
Posted by Ethan Jacoby in Construction, Preparation, Wings, Workshop on March 14, 2010
2.0 Hours -
The work in this post actually occurred in short spurts over a couple of days, but I’m lumping it together.
With the bases cut and the columns glued and screwed, I was ready to put them together. However, I wasn’t happy with the tops of three of the columns being uneven. Granted, the tops being uneven doesn’t even matter, but for appearance sake, I wanted to even them out. After all, when I’m done with the stands, I plan to give them to another builder and I don’t want them to think my work was sloppy!
To even out the stands, I just ran them through my band saw. Due to their length, I couldn’t balance them on the band saw table by myself, so I convinced my girlfriend, Amber, to hold one end of the column up while I cut the other.
Once the columns were even, I started attaching them to the bases. This was relatively simple, and I had all of the bases attached within 45 minutes.
Attaching the bases to the columns was a bit of a stretch. Please ignore my gut hanging out!
The basic stands are done. Now they just need to be reinforced.
Finally, I started working on the reinforcements on the base of one stand. After about an hour, I had the first stand completed. One thing is for certain…these stands will be sturdy. Based on the first stand, they should have no problem supporting the wings. Building the rest of the stands should go more quickly now that I’ve got it figured out (more or less).
This is the first complete stand...at least the wood portions are done.
For comparison, a finished stand next to an unfinished one.
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