Replacing bell cranks on finished planes?

[frank mccune]

               
      Hello All:

      How would I replace the failed bell cranks on four planes that are already built? Two are profile and two are built up full bodied stunt planes. 

     On the profiles, I was thinking about mounting the bc on the exterior of the  fuselage.  I hate to tear into the wings but perhaps that is the only way.

     Suggestions/Comments?

                                                                                                           Frank McCune

                       

       

[Tim Wescott]

If you do it, do it right.  Cut them up, take out the old, put in the new.  If you're careful about how you make the cuts you can put things back together at least tolerably well.

I've done this, with a plane that was gifted to me.  The job took less time than it would have to build a new plane, so that's something.  The plane that Paul Walker gave me has obviously been cut into; IIRC it was to inspect the control system.  To me, that's a message from Paul saying "if you need to, just cut into the @#$% airplane!"

[EddyR]

  Stop buying other people mistakes. Do not buy used models,motors. You seem to have this constant list of planes needing work and poor performing motors. Not meant  as a did.  You are just wasting time repairing others mistakes. One good plane is worth more than a dozen junkers.
Ed

[Mike Danford]

I had one rip loose, incident, not a normal use failure... a Sig Banshee, just cut into it.  Was pretty skeptical, but it turned out to be a pretty easy job. 

Just seems messy, much more so than it actually is.

Tools

[Dan McEntee]

   It's not terribly difficult, and it helps if you have built a model like the one in question and have a good idea of the entire construction of the center portion of the wing so you know where to cut. Work slowly and purposefully. You may want to try and re-use everything you cut away but may not be able to do that, so as you cut into it, do it with replacing the sheeting and such in mind as you go. You obviously may have to pull off some covering. It's worth recovering even a whole bottom of a wing if you have to just to have easy access to re-doing the lead outs and such.
    Type at you later,
    Dan McEntee

[Dave_Trible]

I'm just curious how you get FOUR failed bellcranks?  In about 55 years at this I've never had one fail.  What failed?  Do you mean a leadout got sawn through or cut through the crank,  bushing gone bad or...?   

Dave

[Ken Culbertson]

I'm just curious how you get FOUR failed bellcranks?  In about 55 years at this I've never had one fail.  What failed?  Do you mean a leadout got sawn through or cut through the crank,  bushing gone bad or...?   

Dave

What Dave Said.

I have had to replace leadouts and I did replace everything in a Nobler ARF once but I have never had one fail.  I use floating exclusively and unless you plan for it, they aren't coming out.  If you are going to cut into the wing do not try and fit the piece you took out back in.  Leave about 1/4" on either side and plank over it.  On the outside cut at a 45 degree angle so that you can glue it back in place then sand a little dip and glass the joint.

I will bet once you get in there that the bellcranks themselves are not the problem.

Ken

[Chris McMillin]

The Eddy to Frank reply is probably apt. The way some profiles are built one could slide the wing out!
Chris...

[frank mccune]

     Hi Eddy et al:

     The planes in question were a real bargain! They were really nicely finished and ready to fly.  At $25.00 each, I could not resist.  They had Fox .35 or McCoy engines installed along with mufflers and tanks.  All I had to do is to hook a set of lined to them and enjoy.  One was totaled due to b.c failure.  The three remaining, exhibited bc failure while attaching lines!

     The bc were his own design that were progressive in their movement.  Very little throw around neutral but a large amount at the extreme deflection.  This was a large circular device that had the pushrod mounted on a moving crossbar did the work.  I think that the screw at the centre mounting may have come apart. In any case, they really flew well!

     Hi Eddy: Yes, I have come to the same conclusion about using used items!  Life is too short for all of this mucking about!  I am weeding out all of my junk as I continue to fly.  Today I witnessed a chap spend the entire day attempting to get his K&B Stallion running.  He finally gave up and went home without a flight. Those days are over for me.  I have so much "stuff" that should work well but I will not know unless I try them.  Oh yes, do not purchase used items from "friends."  I have had much better luck with E Bay purchases than purchases from friends!

      Thank you for all of the replies.
 
                                                                                                              Be well,

                                                                                                              Frank McCune

[Ken Culbertson]

   spend the entire day attempting to get his K&B Stallion running.

I actually did get one to run once...only once.

Ken

[EddyR]

Hi  Frank.      I have seen these models show up at the Huntersville contest for years.   Yes cheap at $25 if you want more old Fox or McCoy motors.
  When the shinny plane is checked out at home all the problems start. Leadouts only move 1/2" for full control or the flaps will not move at all. Controls built with 1/16 pushrods  ,well  that's what came in the kit. Flap horn not mounted to the trailing edge and it is moving up and down.   Stab is built tipped high on one side and not square to the centerline.  Motor mounts crushed or motor not offset to outside of circle. Now after you have repaired all the above you just notice it has a built in tank and it will be rusted beyoud use..   The list goes on and on . Aluminum bellcrank with flex steel leadouts and more than likely the ends are solderer nice and tight. 
   Not picking on anyone just look at what you are buying. Wasted time and money.
EddyR

[mccoy40]

Wow!

  " Today I witnessed a chap spend the entire day attempting to get his K&B Stallion running.  He finally gave up and went home without a flight. "

That is why I always start and run my engines at home first. 2nd reason is if something seems off I can log onto the forum and ask.

I'm not a great flyer and have had to repair .... well, everything! The only time I could not fix the belcrank on a plane was when it was mounted right under the profile fuse.

My first failure of a belcrank was the leadout - so was the second time. I would suggest putting the belcrank on the outside and try flying the plane that way. it is the easiest fix.