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General control line discussion => Open Forum => Topic started by: frank mccune on June 26, 2014, 06:47:52 AM

Title: When are 52' lines the best size for stunt use?
Post by: frank mccune on June 26, 2014, 06:47:52 AM
        Hi All:

         I have been using 60' lines for most of my Sport Flying on all of my planes. I use 52' on my .15 size planes and am happy with the results. However, something the other day made me rethink what length of line to use on different airplanes.  One size may not fit all!

        I was flying a third hand Super Clown that the previous owner could not get it to maneuver.  It could not even do a very large loop!  This plane is powered by a  Brodak .25.

        I got the plane from the owner after he crashed it,  repaired it and added some tail weight!  I had about twice as much tail weight that I needed so I removed half of the weight and no the plane flew, but not well.  A friend of mine who was watching this spectable suggested that I try shorter lines.  I just happened to have a new set of FAI lines with me so I tried a flight with them.  WOW! what a difference! The plane no acts like a stunter.  It stays out on the lines, does not flop around in maneuvers and responds very well to control input. It grooves!

      Now the big question! Does each plane/engine combination require a certain length of lines to extract the maximum performance?  I always used 52'and 60' but I may be missing some tuning advantage.

      Have you other fliers found that different length of lines for different planes make a difference?

     I have a large stash of .09-.15 planes hanging in my attic that may require 35-45 foot lengths.

     Any suggestions regarding line lengths for various sized planes?

                                                                                                                         Tia,

                                                                                                                         Frank
Title: Re: When are 52' lines the best size for stunt use?
Post by: Derek Barry on June 26, 2014, 07:12:40 AM
I fly my full sized stunt plane (PA .65 and 700 square inches) on 65' solid lines.

The simple answer is yes, lines do make a big difference in performance.

Derek
Title: Re: When are 52' lines the best size for stunt use?
Post by: Perry Rose on June 26, 2014, 09:38:25 AM
I buy the line bulk from MBS and make a set for the plane a foot or so longer than my TLAR says it should be and then shorten from there until the length matches the plane/engine/my ability. If I build another plane close to the size and power of the first I'll start with the used set of lines. In general for .25 engines I use 58 foot, for .35 to .40's 60 foot, for .46's 62 or 63 foot and .60's 64 to 65 footers all eye to eye.
Title: Re: When are 52' lines the best size for stunt use?
Post by: Steve Helmick on June 26, 2014, 11:42:28 AM
Sometimes, shortening the lines 12" makes a huge difference. In general, a little shorter lines or more tipweight can make a huge improvement in line tension, if that's what's lacking. Can we assume that it's not the pushrod bending or something silly like stiff hinges?  D>K Steve
Title: Re: When are 52' lines the best size for stunt use?
Post by: Trostle on June 26, 2014, 12:11:37 PM
Using various line lengths is one of the tools in trimming a stunt ship for improved performance/feel.  There is no "BEST" line length for a class of models.  Try different lengths  and see what happens.

OK, I guess you could get a fleet of airplanes and find out which one works best for your 52' lines.  So, instead of optimizing lines for a better flying airplane, you could optimize the airplane where the 52" lines work best.  However, I think I would rather work with the various sets of lines I have in my box when I start flying a new airplane. 

Keith
Title: Re: When are 52' lines the best size for stunt use?
Post by: George on June 26, 2014, 05:16:14 PM
Don't forget that the diameter of the lines is important too. A set of 52'x.012's will fly much better on a .15 than a set of 52'x.015's...I found that out the hard way many years ago.

George
Title: Re: When are 52' lines the best size for stunt use?
Post by: Tim Wescott on June 26, 2014, 06:04:33 PM
The best line length also depends on the engine's output.  I have a Ringmaster that does great on 60' lines and an FP-20, but when I tried a 25-S (old baffle-piston engine), the thing barely stayed airborne on the usual lines.  It was better on 55' lines, but still sickly (I swapped the FP back in).
Title: Re: When are 52' lines the best size for stunt use?
Post by: Jim Thomerson on June 27, 2014, 12:50:26 PM
Way I look at it is that a particular airplane-engine-propeller combination has a particular speed at which it flies the best.  So, assuming I have found that sweet spot,  I fiddle with line length until I get both acceptable line tension and lap time. i may have to do some subtile re trimming with change in line length.
Title: Re: When are 52' lines the best size for stunt use?
Post by: Tim Wescott on June 27, 2014, 12:52:36 PM
Way I look at it is that a particular airplane-engine-propeller combination has a particular speed at which it flies the best.  So, assuming I have found that sweet spot,  I fiddle with line length until I get both acceptable line tension and lap time. i may have to do some subtile re trimming with change in line length.

This is probably the wrong approach, but for my current ride I decided on the line length, and then fiddled with the engine setup and prop until I liked how it flew.

I really should try it on shorter lines, just to see, but I like my twister on 65' lines...
Title: Re: When are 52' lines the best size for stunt use?
Post by: Steve Helmick on June 27, 2014, 01:48:17 PM
Tim...Bigger engine, longer lines. Your Twister(ed) has a .46, while the one I gave you had the .36 (and weighed more). I'd like to see you experiment with shorter lines on your current ride. And please do something about that trike gear...maybe just different wheels/tires? I'm on Howard about the current wheels on his new dog too. The ones on the "KISS!" were horrible if not landed perfectly smooth...but I thought that would be better practise than to make it too easy, ya know? Dave Brown wheels are really better than some of the other brands (won't mention GP and Hobbico ;) ).    H^^ Steve
Title: Re: When are 52' lines the best size for stunt use?
Post by: Tim Wescott on June 27, 2014, 02:21:41 PM
Tim...Bigger engine, longer lines. Your Twister(ed) has a .46, while the one I gave you had the .36 (and weighed more). I'd like to see you experiment with shorter lines on your current ride. And please do something about that trike gear...maybe just different wheels/tires? I'm on Howard about the current wheels on his new dog too. The ones on the "KISS!" were horrible if not landed perfectly smooth...but I thought that would be better practise than to make it too easy, ya know? Dave Brown wheels are really better than some of the other brands (won't mention GP and Hobbico ;) ).    H^^ Steve

I had changed the nose gear out to one about 1-1/2" longer, to accommodate a 12-1/4" prop.  Then I switched to an 11" prop and liked it, but didn't put the shorter nose gear back in.  I just put the shorter nose gear in; we'll see in August how it does on pavement.

Hwheels.  Huh.