The International Cessna^® 170 Association

Does anyone know what the correct rudder cable rigging setting up is and what the correct cable tension is for the 1953 C170B? The 100 series manual is somewhat vague.
Thanks in advance.
Morgan

primarily, there isn't a set tension.....You just don't want the cables dragging on the belly

The static rudder cable tension is only that of the return springs. Once your feet are thereon, it depends on how hard you push on the pedals. If you're traveling along at about forty MPH in the last hundred feet of the runway on your roll out, there is probably a hell of a lot of tension on those cables.

blueldr wrote:The static rudder cable tension is only that of the return springs. Once your feet are thereon, it depends on how hard you push on the pedals. If you're traveling along at about forty MPH in the last hundred feet of the runway on your roll out, there is probably a hell of a lot of tension on those cables.

Yes, the rudder cable tension is not specified because they are not tensioned, except by the rudder-pedal springs.

Morgan,

The question is more than just rudder tensioning springs and should be addressed as such. First, the TCD data should be consulted for the rudder travel information and the rudder mechanical stops be adjusted if required. Second, the rudder tensioning springs should be inspected for proper tension and proper installation. Third, and just as important the rudder pedal travel should be looked at for any conflicts with bottoming on the firewall before hitting the rudder mecahanical stops on the lower rudder hinge. Overall this is called a rigging check. If there is such a conflict a simple shortening of the rudder cables by way of turning the turnbarrels to shorten the cables can cure any conflicts.

Also, Spring is not a bad time to look the rudder control system as a whole over for any wear, wind or prop wash damage. I have found pulley brackets ripped loose, cables poped off of pulleys, fairleeds worn through, worn cables, etc, etc, ....

Hope I was of some help.

gahorn wrote:
Yes, the rudder cable tension is not specified because they are not tensioned, except by the rudder-pedal springs.

Or the rudder pedel pusher ....Brad

Just to add a few words to Minton's post from April.

With a new to me airplane came a few new to me things. One was what everyone characterized as sensitive Goodyear brakes in conjunction with Goodyear cross wind landing gear. Well as hard as I'd try I could not land or taxi this airplane without unintentionally applying right brake. I started to insist the right brake was coming on with just right rudder application but my partner who has been flying this airplane insisted it was just me hitting the brake.

Well after a few very "interesting" landings I jacked up the right wheel and while having someone just push right rudder I observed the right brake being applied. After what seemed like a few hours curled up on my knees with my head under the instrument panel carefully observing the pedal/brake action of the right pedal I came to one conclusion. After disassembling and reassembling each part and not getting any closer to figuring why the master cylinder on that right pedal was being energized with just pedal movement. But I did see that the bottom of the peddle was, in its travel, bottoming out on the the pedal shaft and further pedal application would energize the master cylinder and brake. Why was this. And why didn't the left pedal/brake act the same.

There was only one fix. I'd have to modify the pedal so it didn't bottom on the pedal shaft. Funny why only THAT pedal in MY Cessna would bottom out and have to be specially modified. I was ready to do it, had the mod all planned out but I had this little nagging voice in my ear. Kind of sounded like George and it was saying "no, no, don't modify that perfect Cessna engineering. Keep it original, nut". Of course I had a little devil screaming in my other ear " modify, modify, you know better than Cessna".

Placed a call to Del Lehman (Wingnut) late Friday and said "Del I know I shouldn't have to modify this pedal, have you ever seem any problems like this". Well Del says with a touch of Arkansas accent " I just happen to have a whole Cessna rudder pedal setup sitting here in a box. Let me pull it out and look at it while you describe what's happening." Then he said something to the effect 'You know we had the same problem when we worked on Pulley's (Richard) 170. Came up with a specification, I think from George's box of obscure knowledge, that the pedal should be rigged with the pedal hinge line 6" from the fire wall". He said they rerigged Pulley's plane and all was better.

Well I knew that had to be it and sure enough my peddles were adjusted to 5" inches from the fire wall. This forward adjustment didn't allow the master cylinder to touch the fire wall but it was close, as they all are, but it was enough to through off what is a delicate interplay of the linkage, master cylinder and pedal when the pedal was pushed. Adjusting the rudder cables so that the pedal hinge line was 6" from the fire wall cured the problem. Thanks Del (and George's voice)

And there is a bonus. Those Goodyear brakes that have had a reputation for being sensitive. They now work as nice as any airplane brake I've used. Seems Goodyear brakes (or any brake system) are sensitive when they are half energized before you apply them. How long were these pedals out of adjustment? Well the undisturbed paint on the cable turn buckles puts it at at least 17 years and probably longer. I'm wondering if this miss rigging and sensitive brakes had anything to do with this airplane being ground looped twice in 1975.

N9149A wrote:...(and George's voice)....

Are you sure it wasn't Tommy Lee Jones' ?

N9149A wrote: Well I knew that had to be it and sure enough my peddles were adjusted to 5" inches from the fire wall. This forward adjustment didn't allow the master cylinder to touch the fire wall but it was close, as they all are, but it was enough to through off what is a delicate interplay of the linkage, master cylinder and pedal when the pedal was pushed. Adjusting the rudder cables so that the pedal hinge line was 6" from the fire wall cured the problem. Thanks Del (and George's voice)

Bruce, I'm having a hard time picturing where this measurement is taken from the rudder pedal?

The aluminum rudder pedal attaches to what I call the the pedal shaft that is shaped like a T with a pin that goes through the pedal and the top of the T. The top of the T would be the what I consider the hinge line. The item 43 arrow is pointing to it. I measured from this point to the firewall directly behind it. My pedals were set for 5" as best I could measure allowing for the firewall pad. Adjusting them with the rudder cables to 6" fixed everything.

With the pedals at 5" the bottom of the pedal would hit at about where the item 46 arrow is pointing and any further movement would energize the master cylinder. You can make a minor adjustment of the aluminum pedal angle by adjusting the length of the clevis at the top of the master cylinder up or down about an 1/8th of an inch but that wasn't enough to correct for the whole pedal assembly being adjusted to 5". Until I talked to Del I was convinced there was no other adjustment and I'd have to modify the bottom of the pedal by relieving the metal so it wouldn't bottom out.

I have a 1/8" stainless welding rod, sharpened on one end ..(so as to stick through the insulation) and measure the 6" the pedal should be set to. I use it for setting up new rudder cable installations.....Looks like I will be breaking it out at annuals.

Gothca, thanks Bruce.

N9149A wrote:Came up with a specification, I think from George's box of obscure knowledge, that the pedal should be rigged with the pedal hinge line 6" from the fire wall".

Probably splitting hairs here but the Cessna Service Manual on page 10-8, paragraph 10-10, d. addresses rudder rigging for the 150, 172, 175, 180, and early 182's which have a system similar to the C-170, (without the carry-thru cable). It says to "adjust rudder cable turnbuckles to alighn rudder pedals in neutral, 6 1/2" from the firewall to pedal pivot points (5 1/2" on the Model 150)."

Actually, All flight control, and cable rigging, tensions, dimensions, and degrees of travel are in the Pilots Handbook. best regards Mr Obvious

It's great to have all of these resources helping our members along.

I would add that there are probably many more aircraft out there with the same issues.