Back after hiatus

I am back after quite a break from this blog. I have since finished my GP Yak 54 25% and flown it about 20 times. The DLE 55 has a few gallons through it and has run very well. I have not flown it since January 2012 due to career training but will be back in the air soon. I am in the process of checking the plane over from spinner to tail making sure all works and is in place. Few things to mention since I have gone into giant scale RC flight (this is a working list and things will be added as I learn  more):
1. Use locktight on ALL METAL TO METAL screws INCLUDING servos! During my maiden flight a metal gear elevator servo arm screw vibrated right off the servo and if not for the duel elevators on this model... well you know... would have been the 1st and last flight.

2. METAL GEAR SERVOS- all my servos were metal gear except the throttle servo. I figured I would not need a metal gear servo on the throttle... no point in that right?.. Wrong! During another fight (due to my incorrect throttle servo set up) the plastic throttle servo spline could not withstand the sheer forces and broke off the servo... and that leads me to my next point...

3. Always use KILL SWITCHES! When I installed the kill switch in my Yak I figured it was just a safety feature I would probably never use... see point 2. If it were not for that kill switch I would have been flying the model until the fuel ran out at random throttle settings.

Cheap Fuel Can

This can works for me and didnt cost over $30 compared to most I've seen out there these days that run over $100. The picture shows all that I used to make it (It's a 1 gal blitz can). Pretty simple... just drill a hole to fit the brass retainer, screw nuts on tight, add your hose and retainers and fuel filter if you like. I attached the hand pump with velcro to the gallon tank. I loosen the cap a bit for vent before I crank the pump. This set up has worked for me with out any problems so far. There really is no reason to pay so much money on a fueling station when it is such a basic item. If your looking for a basic set up without an electric pump then this works. I Hope its helpful.

Throttle

Some modifications I recently made that have helped a lot with the engine performance...1. I removed the Idle screw (no matter how low you try to get your idle, it wont go lower than the idle screw setting) and reset my configuration with my throttle servo and transmitter. 2. I tossed the nyrod I was using for throttle... it sucks.. had too much play/give to it and could not hold a good throttle setting (especially at the low end, like idle), I replaced it with a metal 4/40 threaded pushrod. 3. moved the connection to throttle servo arm to innermost hole, gives better response.

Elevator Linkages

Finished up the elevator linkages over the weekend, have had do do a few things for school since then so have not had time to work on the model. Hopefully tomorrow I will finish the rudder. I'm hoping to have her up and flying within the next week (keep your fingers crossed).
I was having trouble keeping the soldered clevises straight on the push rod during soldering, and didn't have my multi clamp tool so here is the idea I had. Very simple and handy when your trying to keep those clevises straight while soldering. Also don't even breath on them till a few seconds after you have soldered them... the solder is still liquid from the heat and it will allow movement of the clevis if not held in place.

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.