line lenghts

[ken Kubushefski]

Hello,

      I'm new to the forum and rethreading my way back to c/l. Since 1970 things have certainly gained sophistication and complexities. I must admit I'm confused. How do you determine proper line length? Some say 52 ft others 57 ft. etc.
       Either a 25 or 35 engine on a Ukey35. First selection to re=train or a flite streak. Can someone please help?

thanks

ken

[peabody]

Lines are a terrific trim tool, as you will learn as you progress....

The AMA specifies a maximum line length of 70 feet, from the center of e handle to the centerline of the plane. This leads to some confusion occasionally, as old timers and experts frequently measure line length as c/l to c/l, while others refer to the length of the actual lines.

I find that referring to actual line length is the easiest.

I would suggest an LA 25 on either the Flite Streak or Ukey 35....and would also suggest that you use .015 lines (.012 are allowed in competition) as they are easier to maintain. I would start at 56 feet, "eye to eye" (overall) .

Try a 9X4 prop and you'll be in business!

[Bob Reeves]

Things do get a little more complex with the acquisition of knowledge. BAck in the 70's I bought ready made lines in basically 3 lengths 52's for 25's 58's for 35's and 68 for ST 46.. Today I have 58, 60, 61, 62, 63, 64, and 65 foot lines and they all are used with separate airplanes. I fly my FP-25's on 0.012 - 58's but Peabody's sugestion is a good one...

How on earth did we fly 60 size ships with ST 46's on 68 foot lines. I remember doing it and wished I still had the reflexes and "no fear" I had back then...

[Brett Buck]

How on earth did we fly 60 size ships with ST 46's on 68 foot lines. I remember doing it and wished I still had the reflexes and "no fear" I had back then...

   A lot less reliably than we do now!  I have had the opportunity to fly at a moderately high level all the way from Foxes to ST46/60, up to the present. The world is a completely different place than it was back then. At the beginning of that time, we were seeing flashes of our current performance, in the form of the "schneurle wars" motors (40FSR, etc, and then the "best motor ever" of the month), and Ted's early experiments with 4-strokes.  That never really worked out, until Hunt and Pappas started using pipes. That was a remarkable quantum leap - and for the most part, it's been pretty easy to fly stunt since then.

  I get to fly a lot of OPPs, and a lot of them are throwback models from the 70's 80's, as far as technology goes. Even with all my subsequent experience, and success in contests, I can hardly do any better now than I did then.  Lack of effective power is a severe limiting factor in the performance. Particularly in bad conditions - with 4-2 break motors, in 10-15 mph of air, the trick was to simply get through the pattern, and if you did, you were probably going to win. Many is the time that I sat there like a spectator at the bottom of the vertical 8, holding full up and hoping that it would pull out above the ground.  Now, you have to care about doing a really good pattern; you are expected to fly just as accurately as you ever do.

    That's what sometimes frustrates me about a lot of internet discussions about engines. So few people actually grasp how much better we have it now, and continue to try to learn all the magic tricks to "fix" these old systems to try to compete against piped engines, Retro 60's, electrics, and to a lesser extent, 4-strokes. These are all so much better than the world's best ST46 (and I have one of those) it's a hopeless task. In perfect conditions, yes, a few of the super-hot-shots would be able to match up with a modern system. But even a little bit of bad air, and most would have trouble winning advanced.

     Brett

[Bill Little]

(snip)
That's what sometimes frustrates me about a lot of internet discussions about engines. So few people actually grasp how much better we have it now, and continue to try to learn all the magic tricks to "fix" these old systems to try to compete against piped engines, Retro 60's, electrics, and to a lesser extent, 4-strokes. These are all so much better than the world's best ST46 (and I have one of those) it's a hopeless task. In perfect conditions, yes, a few of the super-hot-shots would be able to match up with a modern system. But even a little bit of bad air, and most would have trouble winning advanced.

     Brett

I understand where you are coming from, Brett, even though I am not a top 20 level pilot.  I HAVE had the extreme pleasure of flying a near perfect set up, and I can attest the difference.  Yet some really good pilots (Expertrs and all) still fail to see the point you are making.  They have NOT experienced what the right set up feels like, so they have nothing to base their own package to.  And yet they are quick to defend that what they are doing is as good as anyone..........  that's fine with me, since when I do get to start practicing, I will be ahead of their game already!  You can only say things so many times.

[Randy Powell]

I agree with Brett (there's a shock). 

Last season, rather than experimenting again, I just got an engine that had a long history of performance, listened to Brett and Paul about how to set it up and went flying. Surprise, surprise, I got a lot better. The power was predictable and pretty easy to set up and adjust and I could just concentrate on flying. That was nice.

[Brett Buck]

Hello,

      I'm new to the forum and rethreading my way back to c/l. Since 1970 things have certainly gained sophistication and complexities. I must admit I'm confused. How do you determine proper line length? Some say 52 ft others 57 ft. etc.
       Either a 25 or 35 engine on a Ukey35. First selection to re=train or a flite streak. Can someone please help?

  Can't say  - it depends heavily on which 25 or 35. A 20/25FP does a great job on a Ukey 35, and would use maybe 60-62' of .015 lines. A Fox 35 (not recommended without some mods), maybe, 54-56'. The *size* is not the issue, it's the power output. A 20FP blows a Fox out of the water for this sort of application. A 15FP would fly a Ukey 35 acceptably well, better than most trainers from the 50/60/70's. Just to give you an idea with some common engines that might be considered for a Ukey 35 as a stunt trainer, effective "power" ratings from highest to lowest:

25FP
20FP
25LA/Veco 19 BB
Fox 35
15FP
OS 25-S/Fox 29

   This is assuming stock motors with appropriate propellors at appropriate RPM.


The tendency in competitive stunt is towards shorter lines. I fly my full-house airplane on 64'. It has no problem at all pulling max length lines (67 or so, to get the fuse at 70), but it doesn't provide the kind of precision I want.

     My Skyray 35 with a 20FP uses 62' lines, mostly because  there's so much power that the lap times get a little brisk when the engine is happy. I would suggest using lines as short as you can, without getting rushed. On the same airplane with a Fox I was down to about 56 and was still not satisfied - the speed was still reasonable, but the power was so down that it still had issues with line tension and controllability. When I flew the same airplane with a 15FP, I ended up with the Fox lines.

      This is how I pick my line length. I guess a length based on past experience. In your case, with a modern 25 or so, I would start at 62, with a vintage 35, I would start with 58 or 60. Then I get the engine/prop/airplane running properly and happily, without regard to the lap times. Once I start getting close to a happy engine/prop setting, if I keep wanting to needle it slower, I add 2 feet to the lines instead. If I keep wanting to speed it up, I shorten the lines. If it gets too long, there will be a lot of line sag and a lot of line whip.

     Brett

[ken Kubushefski]

Thank you to all that replied. Makes more sense. The advice is very informative.  Ken