Backflipping?
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Backflipping?
I have read alot of posts on back flipping to start glow engines and I am a little confused on one particular point.
Do I turn the prop counterclockwise until it hits compression and then slap it or do I set the prop so compression is at say 9-3 oclock. Turn the prop till it is at 12:00 then slap it backwards?
Do I turn the prop counterclockwise until it hits compression and then slap it or do I set the prop so compression is at say 9-3 oclock. Turn the prop till it is at 12:00 then slap it backwards?
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RE: Backflipping?
Some twist the spinner to the right against the engine compression (like spinning a top); the engine then fires the piston back in the ordinary direction of rotation. On larger engines, some actually chicken stick the prop back against the compression. I've even heard of some folks who take it all the way thru the compression stroke this way. A lot depends on how easily your engine starts!
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RE: Backflipping?
The technique I use is to turn the prop ccw against compression and then whirl the prop cw with a chicken stick but let go before it hits the compression stroke going backwards, it will fire forward and start nearly every time. Larger engine are more apt to start on one backward flip.
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RE: Backflipping?
I'm righthanded... so I set my prop that the right prop blade (the one I flip) bumps against compression at the 4 to 5 'o clock position...
To start the engine I put that same blade at 1 to 2 'o clock, put two fingers near the prop hub or spinner, and give it a short strong clockwise flip... I pull my fingers out about at the moment where I start to get compression
This may take some practise though... it's all in the wrist... I hardly use any elbow or shoulder... just a quick flip of the wrist and fingers is enough.
Anything below .60 ci can be started in the conventional way: counterclockwise (but don't drown the engine)
To start the engine I put that same blade at 1 to 2 'o clock, put two fingers near the prop hub or spinner, and give it a short strong clockwise flip... I pull my fingers out about at the moment where I start to get compression
This may take some practise though... it's all in the wrist... I hardly use any elbow or shoulder... just a quick flip of the wrist and fingers is enough.
Anything below .60 ci can be started in the conventional way: counterclockwise (but don't drown the engine)
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RE: Backflipping?
I can get my 46fxes to start with a back flip of spinner against compression. It is always neat when it works. With a bit of practice it works everytime. I find it to be a very safe way to start the engine. There is no need to reach over the prop to hold the plane while starting.
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RE: Backflipping?
There is no need to reach over the prop to hold the plane while starting.
#8
RE: Backflipping?
It is a method we call finger bounched starting...
You can hold the spinner at engine and turn fast enough back before it starting. You will save the fingers from propeller.[8D]
I do it allways with my SC 52 fourstroke, Webra T-4.
Jens Eirik
You can hold the spinner at engine and turn fast enough back before it starting. You will save the fingers from propeller.[8D]
I do it allways with my SC 52 fourstroke, Webra T-4.
Jens Eirik
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RE: Backflipping?
ORIGINAL: rkramer
[assuming you don't have a tail trap, if you do, nevermind] until you have the 1 time you accidently have the throttle up when starting...
There is no need to reach over the prop to hold the plane while starting.
Of course, the plane would have to be restrained. Would be kind of nuts otherwise. Goes without saying.
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RE: Backflipping?
My instructor taught me how to do this to my Saito 30. He recomended to adjust the prop to set the blade at the two o'clock position against the compression stroke when rotated CCW. Do your prime. I hold my finger over the silencer exaust hole and turn the prop CW until I hear it make a gulp, slurp, sound of fuel. Then I remove my finger and turn the prop through one more turn in the CW direction to be sure it isn't hydro-locked. Position back the prop, rotated CCW to the compression stroke. I set my throttle at 3 or 4 clicks above idle and then attach my glow starter. I always use a chicken stick because I'm a newbie also and I don't want any bad habits from my beginning, but I see many at my club doing this by hand. Many use the spinner to flip. Personally I'd like to keep all my fingers free from any chance for harm. You generally only get one crack at this... Give the prop a little flip CCW from the 2 o'clock position against the compression, and it kicks and starts running forward, most of the time. [8D] If it is running backwards, it will sometimes flip and run forwards on it's own. Sometimes burping the throttle a bit will help also. And always be sure to check which way the engine is running. It would really suck to look like a pro starting your engine, then run it up full throttle only to have it slam backwards into the tail trap and bust your your alerons.