Aileron Bell Crank

[swift1b]

Thanks to all for your the valuable information on rigging the control cables.
There is one more thing....
I also have a screech in the left aileron bell crank even after much oiling. I do not know if the low temperatures we have has anything to do with this or if the bell crank is worn or bolt or both. I have inspected the cable eyes and the bolt from the top and bottom. It looks like removal of the bolt would be a challenge due to the close clearance with the fabric to the castlelated nut and cotter key. There seems to be toom much play in the bell crank when I move it up and down. Maybe tightening the nut would help?

I will try to attach photos..

bob

[Mark Julicher]

Re: Aileron Bell Crank

Bob,
Yes, the aileron bolt is difficult to remove unless you have the access panel in the top of the wing.

Perhaps a washer under the nut will help?

Is the screech metal on metal or is something just rubbing on excess fabric? The latter can easily happen depending on how the tapes were applied during covering.

[swift1b]

Re: Aileron Bell Crank

Mark

It sounds like metal on metal screeching. I am heading back to the hangar this evening to try to locate the source once again.

Thank you for sharing your thoughts!

bob price

[AndyDuke]

Re: Aileron Bell Crank

Had a problem with stiffness in the ailerons when I bought my Taylorcraft and after much searching found that it was a partially seized bolt in the bellcrank. Cleaned it up and re-greased and totally transformed the handling of the aircraft (in a positive way). The lesson was that it doesn't take much to cause a big difference in the feel of the aileron system.

[Guest]

Re: Aileron Bell Crank

Perhaps a cable is dragging on the fairlead in the wing?

[swift1b]

Bell Crank Screech

I think I found the cause of the bell crank screech in the left aileron. I inserted a mirror in the inspection opening for the bell crank and found the cable near the trailing edge rubbing the phenolite plate where the cable passes through the rib. I held the cable away from the block and moved the aileron and the screech was gone! I check the cable at the right aileron and found the same thing but it does not screech. There was no damage to the cable where it was rubbing against the phenolite plates at the bell cranks.Is this situation normal for the rearward cables? I inspected the entire run of the cables from the fuselage and found it centered in the rib openings. Will appreciate any comments...

sincerely....................bob

[swift1b]

Re: Aileron Bell Crank

I discovered that the bell crank cable near the trailing edge is rubbing on the phenolite? where the cable passes through the rib next to the bell crank. I was wondering if I could apply graphite lube at this location. Any thoughts?

thanks you...............BC 12 D N96323

[Pearson]

Re: Aileron Bell Crank

You need to move the phenolite so that the cable does not rub on it.

[Robert Lees]

Re: Bell Crank Screech

I came across the same problem in a Malibu Mirage last month...the aileron cables, where they purposely interact with the rudder cables with a mechanism, pass through a phenolic fairlead under the pilot's seat, and were squeaking enough to annoy the owner.

I broke the sharp edges of the phenolic with a deburring tool...hey presto! squeak gone. It appeared that the cables were resonating against the sharp edge of the phenolic.

Hope that helps...if you can get access.

Rob

[Guest]

Re: Aileron Bell Crank

perhaps your cables are too loose?

[Guest]

Re: Bell Crank Screech

perhaps your cables are too loose?

[Guest]

Re: Bell Crank Screech

if they are not too lose then paint some para-al-ketone on the cable and fiarlead

[Robert Lees]

Re: Aileron Bell Crank

I've merged these two threads together for completeness.

[swift1b]

Re: Aileron Bell Crank

Many thanks to all who have provided their thoughts. Moving the fairlead (phenolic plate) will be difficult as a hole would need to be made in the fabric. Since both wings have the same condition for the rearward cable could this be a condition that all or most BC 12 D Tcrafts have? A quick check with a light and mirror could determine this. If this condition existed long enough the cable may become frayed. I think I will try to lube for now but add this to my perodic check list. Where can I get the Ketone lube? Are there any lubes that would be detrimental to the cables? I was considering graphite or white lithium grease.

Will appreciate any and all feedback on this!

Wishing all a great day!

bob
BC 12 N96323

[Guest]

Re: Aileron Bell Crank

Hi Bob,

get par-alketone from Wick's Aircraft Supply=>

http://www.wicksaircraft.com/catalog/product_detail.php?pid=6745

Its a standard cable lube for a/c.

Bob, was your cable tension too loose? Moving the fairlead is a modification I would not do that. There are thousands of airplanes working as designed with it right there where the factory put it. I am assuming that there is not damage to it and it is in the original location and condition.

Your A&P should be able to help you with a lot of this, please consult with him prior to making any modifications.

I rigged my ailerons so they they were approx. level with the trailing edge (may have drooped 1/8" to 1/4" can't recall). The cable tension can't be too tight or there is a lot of drag on the controls (and wear), tension is loose enough so that when it flies the aileron trailing edge is up about 1/2" from the wing trailing edge. I picked up a couple of miles any hour.

Forrest had posted this method about 10 years ago and I got it from him. Been very happy with it.

Dave