Wings

Finished up the wings tonight... finally! I'm very happy that the wings are complete. I used the Futaba servos and WOW... all I can say to describe those servos is WOW! They are fast as heck at 6.0V and hold steady as a Oak. The hardware I used are the standard soldered metal clevis on the control surface with the kit included control surface horn and on the servo I attached a DuBro HD ball link. I must say it's a slop free setup. Tomorrow I will be installing the rest of the servos and linking the remaning control surfaces. This truly has been a blast so far. In the next few days I will be completeing the entire airplane along with running the engine and showing how I will make a fuel can for under $30... those things are getting very expensive for no reason. Stay tuned ;)

More Barbs, Servos, and Screws!

Tomorrow I'm going to solder on the other couple barbs I need on the pipes. I have been advised that it's best in large scale RC aircraft to have barbs on both ends of the pipe leaving the tank.

On a separate note: My new servos came in. I could not get the first set of servos I purchased to center so I returned them for a full set of Futaba. That's right.. I'm going all out Futaba now! After 2 years of solid Spektrum loyalty I am switching sides as far as radio equipment. I'm not going to make this post about bad mouthing Spektrum or any other brand. I just simply have had a few issues with my Spektrum equipment and at the same time the Hitec servos that I read much about others having trouble. Even after all the information I reviewed about Hitec I still gave it a try... It just didn't work for me. So hello Team Futaba. The Futaba 8FG should be arriving soon. I will comment on my thoughts about it as soon as I get my hands on it. I have learned that Futaba servos do not come with their own screws and truly don't include much more than a servo, an arm, and rubber grommets along with the little metal cylinder for mounting. You must provide your own screws. The Futaba screws come 10 to a bag and can cost upwards of $5.00 per bag, or you could purchase #4 x 1/2" pan head Phillips screws at your local hardware/home improvement store that are pretty much the same thing and only cost about $1.00 per bag of 16. They both fit through the grommets and length is same, so no worries there. The diameter of the generic screws is a tad larger, but should not be a problem since it's going into wood.

RC Airplane Gas Fuel Tank

Assembly of a gas fuel tank is not very complicated and requires only a couple extra steps and precautions than for a nitro fuel tank. As with with the plumbing of the tank you will need to install fuel line barbs to make sure the fuel line stays retained. There may be some other clamps or something that could be used, but as per instructions for my Yak-54 the barbs are used. So lets take a look at the tank assembly.

Step 1. Preparation and planning (ever hear the saying "Proper preparation prevents piss poor performance?)- Make sure you are using gasoline resistant materials such as tygon tubing, and nitrile stoppers, then decide if you want to go with a 2 or 3 line fuel system. In my set up I'll be using a 2 line with the Sullivan gas conversion kit, dubro 1/8 barbs, and tygon tubing. I should have used nitrile due to the fact that it seems more flexible and supposedly does not harden as much as tygon over time (now I know for next time). Make sure you buy the same size hose as your barbs also. You will need pliers, solder, flux, soldering tool, file, a ruler, fine sandpaper, moist towel, steel wool, a hobby saw or something to cut with, and a vice comes in handy as always.

Step 2. Measure, cut, prepare for solder - measure the brass piping to correct length and saw it, be gentle to not crimp the pipe. When done cutting you may need to smooth out the cut a bit. I used a file to remove jagged shards. Once smoothed out use some fine grit sandpaper to roughen the edges where soldering, then wipe clean with alcohol. Apply enough flux to cover area you sanded.

Step 3. Solder barbs- Apply heat near the area where the barb is but not directly on the barb, I used a small soldering torch and within a few seconds the area was ready to absorb the solder. All you have to do is touch the solder to the area where the barb meets the pipe and it will suck up the solder. Don't overdo it with the solder, keep it neat, keep it clean, and watch out because extra solder will always drip somewhere and if it drips on you it will feel like lava hitting the skin.. not a good thing. Dab the pipe with the moist towel a moment after soldering (be careful at this point, if the solder has not begun to harden you may move the object you were soldering, so let the solder settle for a moment) to cool it. Rub the area you soldered with a little steel wool, then wipe with alcohol again to clean it, blow out any residual dust or particles in the pipe (remember this is going in your fuel tank and can carry debris to your carburetor).

Step 4. Assemble and secure stopper- For the stopper once again you must know how many lines you will use in your fuel system. As I mentioned I used 2. One pipe needs to be bent to face the top of the tank, this is your vent line. The other pipe is your fuel pickup line, it's the one that goes to your carb, and will be used to fill and empty your tank. In a 3 line setup the 3rd line is set up like the carb line with a clunk and used solely for filling and emptying your tank. Bending the brass tubing is very simple and can be done without any tools, just use your hands and be gentle, bend it slowly so it does not kink. The vent should have a little room between it's self and the top tank wall. The fuel pickup line with the clunk attached should have some space from the end of the tank so it can move around freely inside the tank. I gave my clunk about a 1/4" space from the back of the tank.

Now once you have bent and inserted the pipes where they go you will have to insert the stopper into the tank. I had to trim away some excess plastic in the opening. If you need to do the same make sure you get all the trimmings out of the tank so they don't end up in your fuel line. It's helpful at this point to press the stopper into the tank by pressing it down with a screwdriver in the stopper screw. It should pop right into place and then you can tighten that screw for a leak proof seal. Done.