corporateoutcast

I'm a complete newbie to RC airplanes and installed a new OS 46AX engine this weekend and had a question about starting it. It seems like there is quite a level of resistance when cranking the engine. Is this normal? Is this the way a brand new engine behaves? I was watching a video clip of someone testing the same engine and he hand started it with what seemed to be very little to no resistance. The clip is located here, http://www.rcgroups.com/articles/rcp...s/engstart.wmv

Any ideas?

Thanks much!

Jeff

WCB

The resistance you feel is the compression. Yes it's normal. When you don't feel it is when you have to worry. I would never advise a beginner to hand start an engine like on the video. I've seen a lot of people do it that know what they are doing so yes it can be done. Use a stick or a starter. Keep those fingers away from the prop.
WCB

corporateoutcast

got the starter yesterday!

thanks for the reply.

jeff

APIA

That engine is obviously broken in... They do not start with that little effort unless they have a few gallons of fuel thru them. Well you being a newb, go back and watch the video again and note that there are two things that this guy is doing WRONG. Always position yourself BEHIND the airplane whenever possible and NEVER reach around a spinning prop to remove the glow ignitor. I have personally watched a guy get badly injured (lots and lots of stitches) reaching around a propeller. Have fun and be safe...
-Tom

Septic_Shock

Also, I have seen people start these engines by "bouncing" them against compression. If you look he's actually flipping it backwards. The engine then bounces back the correct way and starts up. I've seen it done, and it's pretty cool.

dydx

That dosen't make sense to me. How else can you turn the prop over (either by hand or with a starter) except when you are INFRONT of the plane? Standing behind the plane and trying to start it would be far more dangerous.

APIA

You obviousley DID NOT read my post... I said to stand behind the airplane, whenever possible, and the point that I am driving at is SAFETY...

inferno6688

u still start the plane by standing infront but once started get behind the plane, and as others have said always remove the glow started from BEHIND, same with adjusting the needle. I have stuck my fingers in a spinning prop before and its not fun!

SoonerAce

My Feedback: (1)

Hey SS, It teaches ya respect for a prop really quick if it pops back and whacks a knuckle.[X(] Dem ol' farts have fairly tough fingers, and I still see em bloodied sometimes[:@], but nothin beats a chicken stick( I noticed you had one, cool).....
If ya noticed, sometimes mine will pop over and run backwards. I can usually blip the throttle and it coughs and goes into forward. Its a trip to see it do it.[X(] Course if it doesnt, it dies and ya get another chance.

piper_chuck

My Feedback: (12)

That video is a really good example of how NOT to do it. It's not just that he didn't get behind the plane, but from the positioning, it appears he has put his body in the prop arc. This is the worst possible place to be when starting or revving an engine.

SLOWFLY58

Hi Tom
He is reaching around the prop but also he does not have the plane staked to the ground !!! Guess he never had one covered with exhaust residue to slip through his fingers. At the angle he's starting the plane from he might get a bit more than a chewed up hand [X(][X(][X(] If that plane starts forward and the wing hits his right leg it will turn straight into him. ( Seen it happen )
Not to mention that if the prop breaks he's got a pretty good chance of getting hit with it.

netstalker....
The guy on the video is a complete moron ; NEVER attempt to start an engine this way. There are plenty of ways to get hurt in this hobby without asking for it.

Dale

APIA

Hi Dale
Good point on the greasy airplane. I am fortunate where I fly as we have starting stands. Even with that, these things are NOT toys and if they get away from you can tear you up pretty good. I have seen more that one injury resulting from complacency. The last one that I saw was done by a wood prop and the tendons, arteries and bones in your wrist are no match for a spinning propeller. The only good (if there is such a thing) was that the propeller was wood. I believe that the fool on the video had a composite MA on the engine. Imagine how that would eat you...
Just THINK when you play with these "TOYS",
-Tom

Mode One

Your O.S. .46AX is an easy starting, reliable running engine and a real powerhouse when broken in. It is necessary to start from in front of the engine. So, the plane should be held in position. I do this with a screw driver, driven into the ground in back of the plane and a loop of small rope looped around the tailfeathers and back to the screwdriver. (Remember to remove the screw driver after your done so someone wont trip over it). Or, someone can hold the tail of the plane, or many clubs have starting tables which hold the plane. Once started, it' is safest to move to the back of the plane and remove the glow plug heater and adjust the engine from behind. Your best information on running, care and breaking in of your engine is contained in the engine's instruction booklet. When the Cowboys show up telling you how to do something with your engine, only heed the information they give, which parrots the instructions in the engine booklet! You will hear amazingly stupid opinions on how to adjust the needle valve and break in an engine. DO NOT HEAD!!

bubbagates

My Feedback: (32)

Ok let's take a look at what he did incorrectly in the video. Remember, that prop is a meat grinder just looking for something to chew up and it does not care what that something is.

First thing is the plane is not tied down:

Even if you are alone, never ever start up without the airplane secured. Imagine leaving the throttle wide open or even partlyopen and the engine starting and not having a really good grip on the plane.

Second thing:

Take a look at where the radio is. Yep, right in front of the prop. Again the engine is now running and he is taking it to full throttle, holding onto it with one hand while the other is working the radio.

Third thing:

After starting he remains in the props arc with his right arm and most of his body while testing the engine at full throttle.

Let's say the engine starts but is running in reverse so he blips the throttle while holding onto the plane with his right hand and now the engine throws the prop due to the sudden direction change. I know you are going to say that it's changing direction in a way to not toss the prop nut but I have personally experienced an OS160 where I blipped the throttle, the engine kicked to turn the proper direction and then kicked backwards only to toss the prop off which proceeded to stick itself in the leg of the table right next to the plane. I learned at this time to shut down the engine if it's running backwards and restart it. Thankfully I was no where near in the props arc when it tossed it and the next closest person was quite a few feet away.

Lots of people have made really good suggestions about the safe way to start and test the engine before flight. What I have found that helps me is to ask yourself this.

How can I start and test run the engine while reducing the time that I need to be in front of the prop or reaching over the arc of the prop.

Those 2 items alone will help you be a safer pilot in regards to engine/prop proximity. Even with a plane tied down, sometimes you must reach over/around the prop to hold the plane, especially if you are using a starter. What you want to do is minimize that exposure time.

I've seen a member with years of experience make the mistake of bumping the throttle stick to half throttle, having the plane tied down but with some slack in the rope and the engine fire off and go to high rpm and jump towards him. This member instinctively reached to stop the plane but unfortunately reached right through the prop.

38 stitches on the top of his hand and 57 stitches on his forearm later he was still chewing himself out for not checking everything before startup. Thank god there were tons of people there that were able to help him and get him to the hospital quickly.

150flyer

OK, he is doing it wrong. How many more ways can you guys say the same thing?

PipeMajor

My Feedback: (1)

I've started my Thunder Tiger 46 Pro that way... It's called a spinner start. Rotate by hand the prop/spinner counter clockwise until you feel it come up against the compression. Then take the spinner and smartly spin it clockwise (backwards) through bottom dead center so it "hits" the start of the compression stroke on the other side. With the battery lead connected and the correct amount of prime in the combustion chamber, it should fire in the opposite direction you spun it against the compression and continue running in the correct direction. At no time do you turn the prop through the complete compression stroke.

It works easiest with a ball bearing engine and a largish size prop (provides a better flywheel effect).

The control line combat guys have a variation of this technique perfected. They run highly modified, high compression .36 engines on bladder pressurized fuel systems with tiny props. Electric starters are NOT allowed. They'll rotate the prop counter clockwise until it just touches against the compression stroke as described above. The prop is adjusted on the crankshaft so the blades are horizontal when this position is achieved. When the judge yells, "GO", they'll strike the inboard prop blade down hard with a well protected finger(s).

AMA Fast Combat is truly an impressive sight (and sound) - both teams primed in their launch stance and the caller counts down, "15", "10", "5", "GO!" The mechanic hits the prop, yanks off the battery lead and both planes instantly jump into the air, screaming along at 120 MPH with unmuffled .36 engines turning 27,000 RPM. Once the airplanes achieve 180ΒΊ separation going straight and level, the horn sounds and the match is on. These beasts can generate up to 50g's in lighting quick turns as they furiously maneuver for a "kill" by cutting their opponent's streamer. Matches can be over in a blink. Midair collisions are common. Competitors typically come to a meet with up to 30 airframes.

downunder

CL combat is the most amazing thing you'll ever see done with models. It beats RC pylon by miles. All you need are nerves of steel, reflexes like a mongoose and a total disregard for your model and engine! With one model inverted you have closing speeds of around 240mph and only 50-60 feet away from you. Great fun...I can't do it......

TexasAirBoss

My Feedback: (22)

Actually, in the video, his fingers never touch the prop. He grabs the spinner. I do something similar. But I spin the engine backward. I grab the spinner between my thumb and third finger, then snap my fingers. Starts right up and my fingers are never in the prop arc. It generally works only when the engine is warm.
The engine is always started at an idle.
There is a good reason why so many folks have been warning you about reaching around the prop arc. We have all seen people badly hurt. There are very important tendons that control your hands and some fairly shallow arteries in your wrist. If you don't bleed to death, you can still loose function in that hand. And then you might not be able to fly anymore, phooey.
It appears to me that most people that injure themselves do it early on, within the first few years of flying. Its like almost anything that has some danger attached to it. The new guy always gets it.
So, you might see folks like me snapping my fingers and my engine comes to life. But that doesn't mean that you should do the same. You should see me reach for the glow driver. It is a very exaggerated and deliberate movement that I have done for years and could not do it any other way now. But we all have our routine, our ritual that insures we don't get hurt and that the plane is ready to fly. You will need to develop your own. And do it the same way every time. Do things very deliberately and carefully, don't rush, and always be aware of what your doing. Don't allow others to distract you when you are starting up.
That plane could be strapped to a pile of cinder blocks and nailed to the floor and still ruin your day if you reach into the arc. Guns don't kill people. People do. Its the same thing. Just maintain a heightened awareness when you start up.

PipeMajor

My Feedback: (1)

I have some home shot footage of one of the big CL Fast Combat money meets - the 1991 Bladder Grabber. Have several shots of launches and 3 excellent match sequences. One follows the models as they fight it out to the finish, the other highlights the pilots and the action in the circle (also quite busy).

Several of the well known combat flyers are former RC Formula 1 Pylon flyers. Hopefully someday I'll get the video uploaded to my web site and share with everyone else. It really catches the attention at a mall show!!