Hi all, like I said I am new and need help. I am an American living in Germany. I have tried to get in touch with some local clubs, so far only one person has offered help, he is also an American, he flies with Lufthansa and its hard for us to get together. So far I have had to go it alone. I have the advantage of having a reall big field behind my house and the owner gave me the go ahead to fly there, I in return have to roll the tractor out and mow it 3 times a year, he does it the rest of the time.

This is what I have at the moment: A duraplane with an OS Max .40Fx, I think the motor has seen better days, dont seem to have the power any more. I am going to solve that directly as I have ordered an OS Max .46, not sure if its an FP or FX, not the blue one though. My question is this, how do I set the engine up? Please explain the terms to me, such as lean and rich, I am a real dummy at this stuff!! I really appreciate your help.

Hello Jcrispi,
I will start by suggesting that you spend more time looking for help, but I also realize that it may be hard to find. When the engine arrives, it will have a good manual with it. Spend lots of time and almost memorize it! Now for my experience with OS engines. For every question you ask there will be many different answers and opinions, but these are mine after having had many OS engines. I have rarely had to adjust the low speed mixture. When we mention lean, we are saying that there is less fuel, mixed with the incoming air, rich means more fuel in the mixture. I just put the high speed mixture (the big knurled adjustment) wherever the manual tells me to, then start the engine, and make sure it is running very rich. You will soon be able to tell the difference by the sound. I run it rich enough that it is not quite screaming. You will find a point (at wide open throttle) that the engine smoothes out and starts to scream as you screw the high speed in (clockwise). Just back it out a bit from there so that it is burbling a bit, and run a tank of fuel through it on the ground. Then fill her up, set it to where it is just smoothed out, and fly it! Another method to tell if you are getting it too lean, is to pinch the fuel line. If the engine dies right away, without speeding up, you are too lean. It should increase RPMs quickly and die if it is set right. Just remember to read that manual, and ask lots of questions!

Friar_Tuck,

Thanks! I have been looking hard for help and a good club. The closest club I could find has a noise rule, in oeder for me to fly my plane at their field I would have to put a resonator on the motor that costs over a 100 bucks, plus they seem to be a real closed lot. The other club has been okay, the people are allright and they want to help, only problem is they have only one certified instructor and he is on vacation. I did hit the net and bought about every book I could lay my hands on about flying and building. Building is not a problem for me, I have been doing scale models since I was 8, I am fifty now, ALOT of Guillows models are still hanging in the workshop at my mothers house. My brother is 36 and he still wont touch any of them! I threatened him when he was younger with certain pain and disfigurement if he so much as breathed on them!! he still rmembers it!! LOL

Any way, I finally found out what was causing my plane to go so far out, flip over on its back and crash!! 4 props and 3 spinners later!! I tested both batteries after a good charge, Rx battery was way below green, I am assuming that there was a dead cell and I was losing radio contact. I just bought a new set of Nimh batteries for both the Rx and the Tx, I am running them through the charge discharge cycle now, before you ask, the charger/discharger can deal with Nimh batteries.

I am getting ready to rearrange the battery and Rx in the Durplane, I was thinking of placing them piggyback just forward of the CG as the plane has a tendancy to be tail heavy, any thoughts on placement?

Thanks

Jim Crispi

Hello,
Sounds like you are on the right track. I dont remember the CG measurement on the Duraplane, but if you move things forward a bit, it may not hurt. Always remember "A nose heavy plane flies sluggish, a tail heavy plane flies once!" :eek:

Friar_Tuck

I downloaded the manual on the duraplane from Tower Hobbies that was a great help in understanding how it was built and what the adjustments should be. By the way, nice home page! The DR1 looks great! finally one that isn't red!!! You even got Kemph's Jasta Markings correct!! The DR1 has always been a favorite with me, but at the moment it would be to much airplane for me. One of the aircraft I have been considering building next winter is a Fokker DR6, very rare aircraft, I have only seen photos and drawings of the prototype, seems to have the DR1 fuselage, lower wing and what seems to be about the same type of wing that was found on the DR7, it would be an interesting aircraft, but thats later! gotta learn how to get the things in the air and control them first!! Of course I can start building one, I know sooner or later I wil get the hang of it!!

Soo, what do you think of the Nimh battaries? I have heard great things about them, do you know any of the negative sides?

Thanks

Jim Crispi

PS these are my home pages www.jims-store.de Its in German and I havent updated it lately, but it has a good mug shot of me!! LOL!!

The other one is www.bordun.de This is my wifes and mine music homepage, its in German and some of it is in english. Old Folk music is a great love of mine, so when I am not trying to fly, riding my motorcycel or diving I play music.

Ok, you said that you're a newbie and need help so I'm going to assume that you would also like more than just the terms? I'll give what I do for breaking in my engines and tuning them.


First thing you'll want to do before you even start or begin turning over the engine is to take off the backplate and the head and check for little fragments of metal from the machining process. If there is fragments then of course clean the engine out. :D

My next suggestion which is also HIGHLY reccomended is to get ear protection. SImple earplugs will do. And if you're adjusting the mixture needle using your ears instead of a tachometer you'll still be able to hear the rpm increases and desreases just fine.

Ok as to breaking in the engine. I don't know if you want this or not, but I'm gonna post it anyhow just in case. The only thing I use the manual for is to find out how far out to set the needle valve for starting. The method I'm going to tell of for breaking in an engine is for non-ringed engines. This method is for ABC engines only though, so make sure yours is before doing it this way.

For a .46 engine you should use a 10x6 prop for this procedure. First you'll want to turn out the needle valve as far as the manual suggests to get the engine started. Once it's started then go to full throttle. Now once it's at full throttle slowly start turning in the main needle valve to lean it out. As it begins to lean out it will start to lose rpm's. Once it begins to do this richen it up just a little bit to get the rpm's back up. Run it here at this slightly rich from dead lean setting for two full minutes at full throttle. Then shut the engine down. Let the engine completely cool down. After it's cooled down repeat this procedure once more. And after it has cooled down again you can begin tuning the engine.

The theory behind doing it this way is as follows.
ABC's will expand when they get hot, always. They are therefore designed that way. So when brand new, they are too tight at the top when cold. If you break them in without heating it up, then you will loose the good fit as it grinds away in the 4 stroke mode. Also its hard on the con rod.


So the first couple times through the thermal process, the piston and sleeve will change size the most, then they take on a kind of set and then they won't change so much. Happens with all machined things.

So the first two runs, you let it spin up and get hot on the piston, without load so the conrod and bearings can run in. This takes the piston/sleeve through the heating processes, twice, and they will take a set. Then you'll have about as good a fit as you can get. "Not my words" But that's the reason why ABC's are broken in this way.


Now for the tuning aspect of the engine.
This was taken I think from these forums somewhere. I don't want to re-type it in my own words so I'm just going to paste it.

"Carburetor Adjusting 101
Here's a scenario: Pilot takes off, plane's engine sounds great. After several minutes of flying, engine seems to lose power, sounds kinda "thin", pilot keeps flying. Engine continues to sag, now full throttle is very weak, pilot now understands that maybe this isn't gonna clear up. Engine dies (what a shock! ), pilot calls for deadstick landing overshoots, tears off landing gear, etc. Never seen this at your field, right?

Here's the way that *I* set mixture on non-airbleed carbed engines (90% of the engines out there fit this category, but the theory is similar for air-bleed carbs). First of all, understand that the high speed needle has its main effect from 3/4 to full throttle, and the low speed needle controls everything from idle up to 3/4 throttle. It thus makes sense to me to spend the biggest majority of my tuning time adjusting the needle that controls the largest portion of engine running, right? Also, remember that there is a proper air to fuel ratio (mixture) that allows the engine to run properly. Too much fuel is rich, and too little fuel is lean. We "richen" the mixture by adding more fuel (turning the needle out, or counter-clockwise), and we "lean the mixture out" by decreasing the fuel (turning the needle valve in, or clockwise).

I start the engine give it full throttle, and lean it to it's highest rpm (peak), then richen it by maybe a quarter turn. Then with the glow plug igniter still attached, I slowly close the throttle to an idle rpm. At the lowest rpm that the engine will still reliably run, I then remove the glow igniter. If the engine dies immediately, I know it's too rich, and I then lean out the LOW SPEED NEEDLE by 1/8th of a turn (don't touch the high speed needle). Start the engine again, (and this is important) give FULL throttle briefly to clear out excess fuel, then slowly close the throttle again. Remove the glow igniter, and this time it may run a little longer before it dies, so lean the low speed another 1/8th turn. Re-fire the engine, give a burst of full throttle to clear it out, and slowly close the throttle again. remove the glow igniter and now notice that the rpm DROPPED a bit when you removed the glow igniter, but the engine kept running. We're getting there. It's still too rich, and you'll prove that by opening up the throttle and hearing the engine "blubber" then die. That's because excess fuel has collected in the crankcase during the rich idle, and when you opened up the throttle, the excess was pulled into the cylinder, making it WAY too rich. Supposed you were on a landing approach, and decided to go around, you throttle up but the engine "blubbers" and then dies (another thing we haven't seen, right?). Yep, the LOW SPEED needle was still too rich, allowing excess fuel to collect in the crankcase, just WAITING on you to try to go around so it could "LOAD UP", blubber, and die!

Keep leaning the low speed needle down until it idles well, but now, when you open up the throttle, it HESITATES instead of BLUBBERS. When this happens, you've lean it down too far, so richen it up 1/16th of a turn and try again. You know you've got the LOW SPEED needle right when you can fire it up, remove the the glow igniter, and the rpm doesn't change AT ALL, and you can open the throttle up, and it doesn't blubber or hesitate, it just runs!

The final thing you do is re-adjust the HIGH SPEED NEEDLE, leaning it to it's highest rpm (peak) and then richening it up maybe 1/8th turn to give it a slightly rich mixture. We also know that the fuel mixture will change in flight when you point the nose up (harder for fuel to travel uphill) and also as the fuel level in the tank changes. In both cases, a leaner mixture results, so we actually need to set the mixture a bit further on the lean side to account for this. While the engine is running at full throttle, CAREFULLY pick the model up and raise the nose to at least a 45 degree angle while listening to the engine. If the engine sags a bit, then you'll need to richen up the high speed needle 1/16th turn. Try it again, and when you can point the nose up and the engine doesn't sag, but maybe shows a slight GAIN in rpm, you know you've got it right.

Now the engine will be happy, and chances are will reward you with reliable running. If you've got one of the few engines with an air bleed adjustment for low speed adjustment, the theory is the same, just refer to your manual to see how to richen and lean the low speed mixture.

Gotta go rest my typing fingers!
Tim"


And lastly, if you're training on a duraplane? "Dunno if you are or not"? Then I suggest checking out www.spadtothebone.com They have coroplast models that fly great and are cheaper than the duraplane. So if you mess up the duraplane then just build a spad and keep on rolling. :D

I hope this helps:p
Josh

Jay

Thanks! That was a big help, I used your instructions to break in the .46, motor is a real screamer!! I also just finished putting the final touches on the .60 trainer from tower hobbies I bought awhile back. I have had some problems with setting up the pushrods for the elevator and rudder, they bind a wee bit at the tail exit holes, would it be okay to enlarge the holes? or should I put a bend in the rod portion? If the bend is the way to go how should I approach that? I ask because sometimes a logical solution produces even more problems, and the simplicity of the action generally increases the complexity of the results.

A bend is a bad idea as it will tend to flex under load. make the runs as straight as possible. I'd enlarge the hole enough to prevent any friction.

I assume you have a metal control rod that slides inside one or two nylon sleeves all the way from the servo arm to the surface control horn. Check and see if your trainer has the rods overlapping one another, that's how I do it. When I put controls in of this sort, I run the elevator out the right side rear fuse exit to the horn and run it up inside the fuse to the servo on the left. This makes for a more gentle sweep of the control rod with less tendency to bind. The rudder would come out the left side of the fuse and it is hooked to the servo on the right. If you can spot a bind in the exit hole(s), carefully enlarge or elongate it to remedy the bind. Make sure the control horns on the surfaces are in an ideal position and alignment to accept the control rod, too.

Jon

Jon

I have two wooden dowels with wire at each end, the dowels themselves dont bind with one another, its a problem of the exit holes. I wanted to use flex cable, I think they are from Sullivan, but with the aircraft being an ARF this is almost impossible without taking the foil off the fuselage. I will take the enlarge the exit hole advice,

Is it possible to use a hairdryer on covering instead of a heat gun? I have three women in the house, my lady and my two stepdaughters, and have an overabundance of haidryers in various forms of decomposition lying about.