Although the steps of installing the aileron servo and setting the connecting rods has taken several posts for me to explain, it really can be done fairly quickly. But as I have said before, take you time and get it right.
What we will doing next is getting the clevis on the other end of the connecting rods. As I said earlier, we will be using solder clevises here. But if you will be using other types of connections the methods for centering the ailerons and marking the rods will stay the same. The first step here is to center the ailerons and secure them so that we know where to mark our rods. Looking at picture #1 you can see that a couple of craft sticks (a.k.a. Popsicle sticks
) and several clamps do a good job of centering the aileron. Doing this will ensure that your ailerons (or other control surfaces) are centered even with the wing. Next attach the clevises to the control arm of the servo. I usually will place them in the furthest hole out (picture #2), but it doesn't really matter as we have plenty of room for adjustments at the other end of the rod. After you have attached the clevises the control arm make sure that the control arm is sitting squarely to the servo body, it should be at a 90° angle to the servo body. The control rods should already be attached to the torque rods. Lift up the rods so that they lay right next to the solder clevises on the servo arm (picture #3). Using a permanent marker you will want to mark on the control rod where the back of the clevis will sit (picture #4), make sure you mark both rods now before you disassemble them to solder on the clevis. Now we know where the back of the clevis will be on the control rod we need to cut the rod to length. You will want to have enough extra rod so that it just extends past the body of the clevis (picture #5). It's easy to forget right now but go ahead and slip the other piece of fuel tubing onto our control rod and slide it all the way down to the other end of the rod (picture #6). Use a piece of sandpaper to “roughen up” the rod (picture #7 and #8) as this gives the solder something to get a little better grip on with, just make sure you don't grind off where you marked the control rod. Secure the rod in a vise, or something else that will securely hold the rod but won't be affected by the heat of the soldering iron.
Making a good solder joint isn't hard, but it may take a little bit of practice to get it right. You may want to practice on a scrap piece of material a few times before you try in on the rod that goes onto the plane. A lot of people seem to get all worked up about having to solder, but trust me it's not all that difficult to do. Just take your time and you'll be fine. First of I do want to apologize that the pictures are a bit fuzzy, I didn't realize that until it was too late to take more pictures, but you'll be able to get the idea of what I am talking about. In order to make a good solder joint we need a few things, we need the material that is being soldered to be clean and free from oils, we need a good solder, and we need a clean and hot soldering iron. In order to have clean material to solder together we need to clean the two surfaces off. To do this we use a material called “flux”. Put a little bit of flux on each surface and when heat it applied to the material it will cause the flux to clean the surfaces (please don't ask me to explain how because I don't know myself). You can pick up a tube of flux at your local Radio Shack, and a tube will last you for years. The easiest way to apply it is to take the lid off of the tube and stick the end of the rod into the tube, then when you slide the clevis on the flux will be on both surfaces. Next we need a good solder. The one type of solder that you want to avoid is the acid core type of solder. The reason for this is because the acid in it can actually eat into your material and cause oxidation to start eating into the rods. You can use silver solder here but it's not needed. Either way you can pick up the solder at Radio Shack too. The last item is the soldering iron. I use a dual setting iron that I picked up at (you guessed it, Radio Shack) that I really like. It's two settings are 25 watts and 40 watts, between the two settings I can solder most things that need to be done for our hobby. Since we're going to soldering to a large rod we'll need to use the higher heat 40 watt range. If you already have a soldering iron that is of lower heat don't worry, you can still use it but it will take a little longer to heat up your surfaces. To ensure that the iron it clean use a damp sponge and wipe the tip of the iron on the sponge when it's hot. After the tip is clean you'll need to “tin” the tip. Fancy term, but very simple to do. Take the solder and apply it to the tip of the soldering iron. This will melt the solder and cover the tip, it should be “shiny” now. You only need just a little bit of solder on the tip to properly tin it. When we start to solder the parts it's very important to remember to heat the parts and let them melt the solder. I can't even begin to count how many times I've seen people try to melt the solder on the iron itself and then hope it “runs” down to the part. This usually doesn't happen. What I actually try to do if possible it apply the solder right at the point where the soldering iron meets the work material. This will let the solder melt and then flow into the work itself. You only need enough solder to fill the work area, if it starts to ball up or is in “blobs” on the work area you have way too much there. The last thing to remember about soldering is that after you have applied the solder that you MUST NOT move or touch the work surface until it cools off. If you do it will disrupt the solder cooling and setting properly and cause a weak joint. One quick and easy way to tell is to look at the actual solder joint. If it's very shiny then you've got a good solder joint and you're good to go, but if the joint has a dull .“greyish” appearance then you have a “cold solder” or bad joint and you need to heat it back up and let it cool properly
Ok, now that we're ready to solder we need to put the control rod in the whatever you plan to hold it with, I prefer to put it into a vice. Don't forget to apply flux to the work area. Then slide the clevis onto the control rod up to the mark that you made on the rod (picture #9). Sorry for the slightly fuzzy picture here (picture #10). I put the tip of the soldering iron so that it touches both the control rod and the clevis itself. You'll see the flux “burn off”, which is actually cleaning the work area. Then touch the solder to the “lip” of the clevis where it meets the control rod. The solder should melt and then flow up underneath the shank of the clevis. When that happens you can remove the heat and the solder from the work area and let it cool down without touching it until it cools. Go ahead and do both control rods. In picture #11 you can see the completed rods installed on the wing.
Pictures
1. Clamping the aileron in it's neutral position.
2. Install the solder clevis on the servo control arm.
3. Make sure the control arm is square with the servo
4. Mark where the end of the clevis will be on the control rod
5. Cut the control rod so that it extends into the clevis
6. Slip the fuel tubing onto the control rod.
7. Roughen up the end of the control rod with sand paper
8. End of the control rod after it's been “roughed up”
9. Secure the control rod in a vise in order to solder the clevis on
10. Solder the clevis onto the control rod
11. Install the control rods onto the aileron servo and the aileron torque rods.
Until next time
Ken