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Building Tips and technical articles. => Building techniques => Topic started by: Clint Ormosen on November 26, 2007, 08:05:05 PM

Title: Ball links
Post by: Clint Ormosen on November 26, 2007, 08:05:05 PM
Typically, I would use a ball link on the flap end of the bellcrank pushrod and on the elevator end of the long pushrod. Does anyone use ball links on all four connections? That's what I intend to do on the Chipmunk unless someone can point out a major downside to it.
Title: Re: Ball links
Post by: Clint Ormosen on November 26, 2007, 10:21:49 PM
Already checked that, Ty. It's good. Thanks for the heads up though.
Title: Re: Ball links
Post by: Greg L Bahrman on November 26, 2007, 10:42:38 PM
<Does anyone use ball links on all four connections?>
I do...but.... I'm nobody. Grins  y1..... ~>..... <=
Title: Re: Ball links
Post by: RC Storick on November 27, 2007, 03:54:33 AM
I do too and I am nobody.
Title: Re: Ball links
Post by: tom hampshire on November 27, 2007, 07:03:46 AM
Doug Moon posted a piece on his forum (RIP) about not lubricating ball links, as the lube would attract dust and wear out the link.  I believe this to be true.  The trouble with them is still that the plastic housing shrinks on a cold day and binds against the ball.  I will run some tests this winter on lapping them to correct this.  Has anybody tried to find an answer to this?  There are some DuBro ball links that have a threaded stud through a split in the housing, but they look too lightly built.  Might there be a link from cars or some other application which solves this?  Tom H.
Title: Re: Ball links
Post by: Alan Hahn on November 27, 2007, 07:30:25 AM
From my RC Helicopter book, what happens is that the dust imbeds into the plastic (if you lubricate the ball link for example) and that ends up lapping the metal ball away. I would say that lapping on purpose may not be such a good idea for the same reason.
Title: Re: Ball links
Post by: Will Hinton on November 27, 2007, 08:52:32 AM
Tom,
My solution for the cold weather shrinkage of the plastic is quite effective and simple - don't fly when it's cold! n1
Signed,
Fair weather wimp. H^^
Title: Re: Ball links
Post by: Ron King on November 27, 2007, 10:06:50 AM
I've used ball links on my RC Helicopters since 1982 and I use ball links on all four ends of my CLPA pushrods. I use teflon to lube all of them and since the CLPA rods operate in a fairly closed environment, I've never worried about attracting dust.

Another nobody,

Ron
Title: Re: Ball links
Post by: RandySmith on November 27, 2007, 10:45:20 AM
Hi

Ball links in stunt ships DO need to be lubricated, I have seen **many** ships that had nice smooth controls at first but then either got stiff or  locked up. I have had to cut into some ships to lubricate and free up the ball links, after they were lubed all was good and back to normal.
Not only does heat and cold affect the link, it seems as though  rain and wet weather  does  also. And I have seen  way too many planes that had to be cut into to free them back up.
Do not use a petroleum based grease or oil. Some times this will attack the plastic.
 I use a synthetic silicone grease or a Teflon type lube. Recently I have tried RC car lube with good results.
I would not worry about dust wearing out ball links in stunt ships, the only dust there would be balsa dust which will not wear them out.
A helicopter is entirely differant, the helicopter will kick up sand and much debris that is very hard and will wear out controls

Regards
Randy
Title: Re: Ball links
Post by: Randy Powell on November 27, 2007, 11:35:37 AM
I've used them at all four positions for the past 5 or 6 planes.
Title: Re: Ball links
Post by: Jim Treace on November 27, 2007, 11:50:09 AM
I am "really" nobody, but I lubricate my ball links (use ball links on all connections). I use TEF-GEL
http://www.tefgel.com/index.htm
I use TEF-GEL on marine and aeronautical fittings, metal to metal and metal to plastic. Never a problem, regardless the temperature
Jim
Title: Re: Ball links
Post by: Clint Ormosen on November 27, 2007, 10:00:15 PM
Thanks for all the responses. I will use them at all four connections. I have the DuBro black 4-40 ball links. Last night it got 34 degrees in my shop and I tested to see if the links got tight. They didn't. I don't expect to actually fly the plane at that temperature so I think it'll be ok.
Title: Re: Ball links
Post by: Randy Powell on November 27, 2007, 10:32:15 PM
Clint,

Well, you'd be better off with Rocket City ball links, but at least make sure you use a retaining washer over the link to keep the plastic from popping off the ball under load.
Title: Re: Ball links
Post by: Bill Little on November 28, 2007, 09:23:15 AM
Hi Clint,

Do you have any of the brass *stand offs* to use at the bell crank?  I find those to really be helpful.
Title: Re: Ball links
Post by: Clint Ormosen on November 28, 2007, 06:14:06 PM
Clint,

Well, you'd be better off with Rocket City ball links, but at least make sure you use a retaining washer over the link to keep the plastic from popping off the ball under load.


I don't know where to get Rocket City stuff anymore. Is there a source?
Title: Re: Ball links
Post by: Andrew Hathaway on November 28, 2007, 06:27:49 PM
http://nelsonhobby.com/rcl.html
Title: Re: Ball links
Post by: Jim Snelson on November 28, 2007, 07:01:21 PM
The ones I carry are the Rocket City version.

Jim Snelson
Control Line Central
www.clcentral.com