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General control line discussion => Open Forum => Topic started by: RknRusty on November 26, 2014, 07:07:52 PM

Title: The leadouts on my Magnum are a time bomb
Post by: RknRusty on November 26, 2014, 07:07:52 PM
The wire is .027" and looks healthy without any frayed strands. If I cut off the old crimps I will I have 2" to work with, so not much there for wrapping with eyelets. How about some of the double barrel crimps that I can get at the tackle shop? Any other ideas? With just the bare wire loop I hook up the scissor clips shown in the pic with the small end in the loop.
(http://i59.servimg.com/u/f59/16/76/00/59/magnum12.jpg) (http://www.servimg.com/view/16760059/658)

I got some good .018" lines that were left to our club by the late Allen Brickhaus. The set I used Tuesday are 65' and I thought the plane felt very good at that length. This set is bronze colored. I wrung the Magnum out for the first time flying a few full patterns with it. Such a graceful plane to fly, a real treat and flies with authority like I'm not used to with the 35 ouncers.
Thanks for any help.
Rusty
Title: Re: The leadouts on my Magnum are a time bomb
Post by: John Tate on November 26, 2014, 08:56:08 PM
Rusty,
Is that Magnum is the one that make Garmon built? It probably had over a thousand flights on it before you got it. I know that Mike Garmon had at least 5 different engines in it. It is a shame that you can not look at the bellcrank to see how much wear and tear there is in there.

You can use a pair of diagonal pliers and nip at the lead-out crimps and try to remove them without cutting the cable (good luck). Then you make the ends up the way you want to.

Personally, I would fly the Magnum until you wear the model out. You should be an Expert pilot by then.

John Tate
Title: Re: The leadouts on my Magnum are a time bomb
Post by: Ron Cribbs on November 26, 2014, 09:14:26 PM
I've removed crimps before. It's time consuming, but will keep the length where you want it. Of course that assumes the integrity of the cable is ok.

Ron
Title: Re: The leadouts on my Magnum are a time bomb
Post by: RknRusty on November 26, 2014, 09:23:04 PM
Yes John, this is the one. I finally got confident enough with it to really cut loose and fly it like it was meant to be. So now that I'm exercising it I started worrying about the leadouts and wondering about the bellcrank and control system too. At first when Y'all gave it to me I wasn't sure if it was in good enough shape for serious flying. But after fixing up some exposed wood in the nose and repairing a loose and misaligned stab, it flies like a dream.

I think it should be kept hot and greasy, no need to collect dust. Mike would probably like that. Howard says Mike used it as a 4-stroke testbed. It has a foam wing. Maybe some other Magnum builder will offer up some tips to help me keep it in shape.
Rusty
Title: Re: The leadouts on my Magnum are a time bomb
Post by: RknRusty on November 26, 2014, 09:27:12 PM
I've removed crimps before. It's time consuming, but will keep the length where you want it. Of course that assumes the integrity of the cable is ok.

Ron
Hi Ron
I had not considered that before you and John mentioned it. I'll try it and look at it with my pocket microscope before I decide to re-use the same wire that was inside the crimps. Looks like it was flattened on an anvil with a hammer. I wonder if that was Mike's way of doing all of his leadouts.
Rusty
Title: Re: The leadouts on my Magnum are a time bomb
Post by: Dan McEntee on November 26, 2014, 09:47:19 PM
   If the leadouts were installed with any thought to longevity, you may be alright. get one of these new LED flashlights that are so strong, and try shining down the leadouts and see what you can see. The area around the bell crank on a Magnum is fairly roomy. If you know someone that has a kit, check out their cores and you'll see what I mean. Maybe if you know a plumber or someone that has one of those flexable snake scopes you can see the ends. I will have to think about it for a bit, but if it is necessary to cut into it, going in from the bottom sounds like the way to go, with carefuly planned cuts through the sheeting and the foam to expose enough of the bell crank to try and change the leadouts. Might be worth the effort.
   The Magnum is a nice flying model. What engine do you have in it?
  Type at you later,
    Dan McEntee
Title: Re: The leadouts on my Magnum are a time bomb
Post by: RknRusty on November 26, 2014, 10:42:20 PM
Dan, thanks for the tips. I have an OS 46fx with a Zinger 12x4 prop. It has surprising power. I'm pretty comfortable with it, though it's a whole new experience flying a plane that's almost as big as me.

I'll see if I can get a look down in there. John and other members of the Norfolk gang can probably tell me more about its history. I'm glad for the opportunity to keep it flying. Hopefully I'll be able to pass it along one day in the same spirit it was given to me.
Rusty
(http://i166.photobucket.com/albums/u116/rknrusty/Airplanes/WP_20141125_002_zps4d42b2ee.jpg)
Title: Re: The leadouts on my Magnum are a time bomb
Post by: Steve Fitton on November 27, 2014, 06:22:18 AM
If the leadouts are not frayed keep flying and do not worry.  Mike's stuff held together real well.  I have his Brodak Warbird P-51 prototype with solid leadouts and they work fine as well.

Having said all that, I would not go and put something irreplaceable, say a PA-75 for example, in any plane I didn't build myself.  That way if something does go wrong you have nobody to blame but yourself.
Title: Re: The leadouts on my Magnum are a time bomb
Post by: Phil Krankowski on November 27, 2014, 06:41:02 AM
It looks like the eyelet fell out.  I would use a small file and remove the corner of the crimp then peel it if I had to keep the current length. 

If there is access to the bell crank I would consider pulling new cable the whole length.  Since you started this thread it probably is safe to assume access was not built in.

Phil

Title: Re: The leadouts on my Magnum are a time bomb
Post by: john e. holliday on November 27, 2014, 09:24:21 AM
If he used the SIG nylon bell crank and tubing for the cable through the bell crank ends, you have no worry.   If he did fly it as many times as stated it would have failed long before now I would think.   I have SIG nylon bell cranks that were not bushed with the cable that still look like new.  It is the sawing action that removes material.   
Title: Re: The leadouts on my Magnum are a time bomb
Post by: RknRusty on November 27, 2014, 12:10:53 PM
It's the eyelets, or the lack thereof, and the grossly flattened crimp tubes that worry me more than the internals. I might to try to snap a couple of large eyelets into the loops and try to forget about the crunch tubes.
Rusty
Title: Re: The leadouts on my Magnum are a time bomb
Post by: Randy Cuberly on November 27, 2014, 02:52:30 PM
It's the eyelets, or the lack thereof, and the grossly flattened crimp tubes that worry me more than the internals. I might to try to snap a couple of large eyelets into the loops and try to forget about the crunch tubes.
Rusty

I would worry that the inner crimp tubes are done the same way.  On the other hand the airplane has survived a long time and many flights.  Of course the far better way of crimping is with a couple of dimple crimps.  The unit loading at the crimp is much higher and stronger that way!

Randy Cuberly
Title: Re: The leadouts on my Magnum are a time bomb
Post by: phil c on November 28, 2014, 12:28:31 PM
What exactly are you worried about with the lead outs?  The crimp tube doesn't appear to have developed cracks.  There are no broken strands in the leadout loop.  The loop is well-rounded.  With the line clips shown there won't/hasn't been any wear on the leadout wire.  .027 stranded stainless such as you've got will last a verrry long time.  The only real wear at the line clip might be from vibration , or a loop  that is pinched to the point the line clip is pushing on the sides of the loop.  That might eventually break one strand which will be obvious.

The internals, as almost everybody else says, might be troublesome mainly because you can't see 'em.  The only serious problem there is if the loop through the bellcrank(metal or plastic) is too tight.  that will make it saw through the bellcrank in a relative hurry-1-200 flights or less.  The pushrod may also wear the hole in the bellcrank completely through and fall out.

Phil C
Title: Re: The leadouts on my Magnum are a time bomb
Post by: Glenn (Gravitywell) Reach on November 28, 2014, 02:43:31 PM
As a few others have said....whats the matter with what you have.  Nothing appears to be wrong with it.  I have used the same system for years with absolutely no problems.  Just keep an eye on it for broken strands....then fix it. H^^
Title: Re: The leadouts on my Magnum are a time bomb
Post by: RknRusty on November 28, 2014, 08:40:24 PM
Well, I read a lot on these Stunthangar forums about how to make things that will last and be safe. So now that I've inherited an old one that I intend to both fly and hopefully preserve, I'm inspecting it for anything that might break. Going back to my first picture, it doesn't strike me as an example of excellence in lead out termination.
Maybe I underestimate the strength and durability of the hammer and anvil crimp tube and no eyelet method.
Thanks for all the replies. I can take it from here.
Rusty
Title: Re: The leadouts on my Magnum are a time bomb
Post by: Ron Cribbs on November 28, 2014, 09:27:08 PM
Well, I read a lot on these Stunthangar forums about how to make things that will last and be safe. So now that I've inherited an old one that I intend to both fly and hopefully preserve, I'm inspecting it for anything that might break. Going back to my first picture, it doesn't strike me as an example of excellence in lead out termination.
Maybe I underestimate the strength and durability of the hammer and anvil crimp tube and no eyelet method.
Thanks for all the replies. I can take it from here.
Rusty

That's funny stuff. Yes, no offense to the builder, but those leadouts are lacking. Carefully nip away at the sleeves and re-terminate properly. You should have enough to work with.





Title: Re: The leadouts on my Magnum are a time bomb
Post by: RknRusty on November 28, 2014, 11:38:35 PM
 ;D