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General control line discussion => Open Forum => Topic started by: raby fink on March 22, 2009, 05:49:22 AM

Title: PROP PLACEMENT
Post by: raby fink on March 22, 2009, 05:49:22 AM
Someone brought up a topic that I would like to know more about, and it got lost in another thread, so I am reposting to get some answers. It deals with placing the prop on backwards to help someone while learning to fly. I got a couple of replies but hope to get more before I try it. I have someone that has never flown before. Will turning the prop backwards slow it down significantly? If any of you have ever tried this please let me know if it helped. Also let me know how the performance was and is it safe and will it hurt the engine. It will be on an Akromaster for someone who has never flown before.
Thanks

Raby
Title: Re: PROP PLACEMENT
Post by: Bootlegger on March 22, 2009, 06:40:26 AM
                  I have done that with 1/2a engines, but nothing bigger, it didn't hurt the small engine, but I never tried it on a larger engine.
                  One thing I would look at is will there be enough power to fly the model at all ???
Title: Re: PROP PLACEMENT
Post by: afml on March 22, 2009, 06:53:18 AM
YEP!

I made the reply pertaining to the Sig 15 size Buster & Shoestring planes.
It also works with larger engines too.

My good friend and I were at the Brodak's contest and flying Foxberg racing for the first time.
I noticed the plane he was flying was a GREAT deal slower than the 3-up competition.
His pit man/builder/owner of the airplane did his best to coax the Fox 35 into a more competitive run.
But to no avail!   HB~>
Seams in his haste to prepare for the race, the owner put the prop on BACKWARDS!     LL~ LL~

 Try it! You'll like it!

"Tight lines!"

Wes

Title: Re: PROP PLACEMENT
Post by: Andrew Tinsley on March 22, 2009, 08:46:34 AM
Hello!

       There is NO problem in putting the prop on backwards. It is much less efficient in flight, so all you see is reduced speed. This technique is often used in freeflight, when trimming out a plane, it prevents any nasties from making a real mess of the plane if it is drastically out of trim! It may be a good idea for the first flight of a new stunt plane. You can operate the engine at its optimum revs, you just get reduced thrust, anything that is drastically out of trim will be easier to handle!

Regards,

Andrew.

Title: Re: PROP PLACEMENT
Post by: George on March 22, 2009, 09:45:48 AM
Raby,

You might be better off to use a low pitch prop in the correct direction. This will yield low speeds with adequate thrust for those times the plane is in a stall...which may keep it flying instead of crashing.

I think you are being way over worried about crashing. As long as you do not greatly over power the Akromaster it is a pretty sturdy plane. Besides, if you built it once, you can build it again.

What engine are you using? I would not use anything larger than a .15 and an 8x3 or 8x4 prop.

Did you go with the balsa sheeting on the wings?

George

Edit: Additional thoughts...a large plastic (cheap) spinner on the front will absorb a lot of impact upon crashing...also, fly over grass.
Title: Re: PROP PLACEMENT
Post by: Serge_Krauss on March 22, 2009, 10:06:33 AM
Someone brought up a topic that I would like to know more about, and it got lost in another thread, so I am reposting to get some answers. It deals with placing the prop on backwards to help someone while learning to fly. I got a couple of replies...Raby

7th from the top:

http://stunthanger.com/smf/index.php?topic=11934.0

There are some good observations here, and an answer to your original question. Go have some fun.

SK
Title: Re: PROP PLACEMENT
Post by: raby fink on March 23, 2009, 03:50:49 AM
Hey George
I think you are right with your thread. I think i am to worried about crashing. If it crashes, we rebuild and smile through it all. If it cant be repaired, I get a new one. I will put a spinner on it to. It will be powered with a os 15 and I am just going to go with monocote on the wings. I hope to have it ready in about a week. Thanks to everyone for the good advice.
Raby
Title: Re: PROP PLACEMENT
Post by: john e. holliday on March 23, 2009, 08:42:41 AM
Way to go,  after awhile you get where you don't crash so much and wind up like me.  Too many planes and no room to build.   I guess that is why it doesn't bother me now with the grand kids and crashing planes.  Having fun,  DOC Holliday
Title: Re: PROP PLACEMENT
Post by: Larry Fulwider on March 23, 2009, 09:57:34 AM
Raby,

You might be better off to use a low pitch prop in the correct direction. This will yield low speeds with adequate thrust for those times the plane is in a stall...which may keep it flying instead of crashing.  . . .

. . .

George
I think George said a lot. That is, I agree. The classic beginner crash is the “too-high-with-the-wind-in-your-face” loss of line tension. Solid thrust helps both prevent that situation and helps to recover from it when it does happen.

Beginners have a tendency to find the ground by trying to stay too far away from the ground at the wrong time. It takes a while for a beginner to learn that line tension, not altitude, is your best friend in control line flying.

Larry Fulwider
Title: Re: PROP PLACEMENT
Post by: john e. holliday on March 24, 2009, 09:29:38 AM
As I tell my students, "It is easier to fly if you fly lower and you can't land up in the sky, let the plane come down".  Of course I am telling them to apply a little up on the handle or tilt it back a little.  DOC Holliday