Rudder Pins and bushings

[Bonanza91K]

The lower rudder pin/bushing is very worn on my F21. Can some one tell me the following before I tear it apart and find out for myself:

Is the bushing steel or bronze?

Is it common for the bushing and/or the pin to wear?

Thanks in advance

Jim

[Robert Lees]

Re: Rudder Pins and bushings

I'm not 100% sure about the F21, but on the previous B models, the bushes were sintered bronze. I have no reason to think that the design was changed.

Your problem is not unique...wear here on the rudder bottom hinge is very common.

The bushing is considered to be a "wearable" item, and can easily be replaced. The bronze bushing should be affixed in the centre part of the hinge, in the fin.

The steel pin rotates in that. The steel pin should NOT rotate in the smaller hinge components in the rudder itself, otherwise it's a steel-wearing-against-steel situation, which is not desirable. The B models used splined (knurled) pins to make sure that they didn't rotate in the wrong part (see picture below).

When the wear becomes too much, a new bushing is pressed in and bingo! New bushings are available from Univair.

I hope that helps, Merry Christmas!

Rob

p.s. the second photo shows the dimensions of the drift to press out (or tap out) the old bushings & press in the new ones, if that helps.

[Robert Lees]

Re: Rudder Pins and bushings

[Edit: I'd suggest you replace the steel pin whilst you are there]

[Bonanza91K]

Re: Rudder Pins and bushings

[Edit: I'd suggest you replace the steel pin whilst you are there]

Thank Robert, that's what I assumed.

Jim from Rochester, NY

[M Towsley]

Re: Rudder Pins and bushings

Jim,

I just posted a thread on this a couple of weeks ago. The bushings you can get locally at a hardware store, they are of a stock size. The knurled pins are carried by Wag-Aero if you don't want to make your own. Also a link on landing gear bushings, etc. There is more info out there, just use the search box. Good luck.

http://vb.taylorcraft.org/showthread.php?10208-A48-Knurled-Hinge-Pins&highlight=bushings

http://vb.taylorcraft.org/showthread.php?10197-Landing-Gear-Bushing-Size-Needed-or-Source&highlight=bushings

[Bonanza91K]

Re: Rudder Pins and bushings

I took the rudder off and found that my pins are straight. I ordered some from Univair but the best fix would be to "full float" the pins with bronze bushings through out. My F21 has a Scott 3200 tail wheel and has heavy tension springs. This puts a lot of pressure on those little bearings on the fin. I'm going to replace the bronze bushings for now but leave in the straight pins. If the rudder bushings wear, I'll make mod to use bronze through out. It's on floats in the summer and Trickair skis in the winter with no tail ski. That fact alone may put more pressure on those bearings from the tail wheel dragging through snow. So far I've broken the shaft on two rudder arms. The arms are cast and the shaft size is only .660 so they are pretty week. I made a new shaft from forged round stock and welded it to the arm so we'll see how that works.

Jim

[3Dreaming]

Re: Rudder Pins and bushings

I think you will find that there is not enough wall thickness in the lugs on the rudder to ream and install a bushing. I guess you could always weld new lugs on, but that sounds like a bunch of trouble.

[8708]

Re: Rudder Pins and bushings

I am installing my rudder and using the knurled hinge pins. The pins that were on it originally were not knurled. The knurls make for a tight fit. Has that been everyone's experience? That is did you have to drive the pins in to install them? Thanks! Jay

[3Dreaming]

Re: Rudder Pins and bushings

The pins should go fairly easy until you get to the knurl. I know that is not always the case. When installed and working properly the pin should rotate with the rudder. If it does not rotate with the control surface that means it is wearing in places not designed to be worn, instead of the replaceable bushing.

[Hank Jarrett]

Re: Rudder Pins and bushings

I know that is how the hinges were designed but I have also noticed on the majority of planes I have looked at the knurled pin is long gone and a smooth pin with a cotter pin is being used. This is also true of almost ALL of the spare tail feathers I have.
On my plane I think there were only one or two knurled pins left and I replaced them because they were rusted. I do make sure to keep the pins well lubricated and often move the pin back and forth on pre-flight to make sure it hasn't stuck to either part of the hinge.
Does anyone have any information on actual wear from NOT using the knurled pins? There is no play in any of my hinges, but again, I am kind of anal about being SURE the pins are not sticking to either the static or movable part of the hinges.

Hank

[M Towsley]

Re: Rudder Pins and bushings

Wag Aero has the correct knurled pins and bushings. I replaced all my tailfeather bushings and pins a few years ago with theirs. Now, if I can just get them to produce some aileron knurled pins.

[3Dreaming]

Re: Rudder Pins and bushings

Hank, I have seen significant wear on a few airplanes, both on tail control surfaces and ailerons. Univair is the only place I have found the aileron pins. They also have the tail pins, but are quite pricy compared to the others. Bushings can be bought at any of these places or often found locally. If you have to much wear new pins will not fix the problem. This is something that needs to be done proactively.

http://www.univair.com/taylorcraft/control-surface/a-8001-taylorcraft-hinge-pin/

Wag Aero or Spruce has the pins for the tail.

https://www.wagaero.com/pin-tail-surface-hinge-taylorcraft.html

http://www.aircraftspruce.com/catalog/lgpages/taylorcraft05-11460.php?clickkey=5008862

[Peterroy]

Re: Rudder Pins and bushings

Why do you suppose the Univair pins would cost three times as much as those from Wag or Aircraft Spruce?

[Hank Jarrett]

Re: Rudder Pins and bushings

Considering how easy it is to put a pin in a laith and use a knurling tool on it why do ANY of them cost much? Any high school machine shop student can MAKE those pins. They are about as UN-complicated as you can get.

Hank

[Robert Lees]

Re: Rudder Pins and bushings

Considering how easy it is to put a pin in a laith and use a knurling tool on it why do ANY of them cost much? Any high school machine shop student can MAKE those pins. They are about as UN-complicated as you can get.

Hank

To knurl that close to the pin head requires more than your average knurling tool.

Rob