The International Cessna^® 170 Association

Removed the control colomn to clean,inspect, paint. Noticed when turning the universals the chain would bind and get tight going in one direction but not the other. Took everything apart, cleaned and assembled, same thing. The turnbuckle, and tube and bar assembly are both shortened all the way. Is it possible the chain is stretched and causing a bind. It seems their should be more adjusment. I took one length of chain and held it by one end sideways and it drooped approx 1 1/2 inches. I ran the part# 0411051-4, nothing shows up. Anyone else run into something like this.
Mike

worN or bent sprockets

I find it very difficult to think that, with the comparitavely very small amount of rotation that those sprockets get, they could ever get any significant wear, and their location should protect them from damage in anything less than a crash.

I have traced it down to the chain. Sprockets could be worn but the chain is stretched. And had tight links. The turnbuckle is adjusted just about all the way in and the tube that the cables attach to is at its shortest dimension. I put the 2 lengths of chain in a bucket of MMO for a couple beers, I mean hours, and it made a big change in the binding. But I cannot find the chain anywhere. I know its made by Diamond, and I know its a 3/8 pitch with 3/16 roller. They offer a nickle plated and the original looks like a nickle finish. I will research it some more and also check to find a sprocket to compare these I have to. Any suggestions appreciated.
Thanks
Mike

Wouldn't the chain just be a standard part that you buy anywhere and just use a chain break to swap out the ends so it can attach to the turn buckles?

if you need one i have a good one for 20 shipped

I will let you know Monday evening after I make a couple calls. Do you have the sprockets also.
Thanks
Mike

blueldr wrote:I find it very difficult to think that, with the comparitavely very small amount of rotation that those sprockets get, they could ever get any significant wear, and their location should protect them from damage in anything less than a crash.

It's difficult to believe a chain could be "stretched". That chain could drive a small motorcycle...certain an adult bicycle... and never wear out. The task assigned it in an aileron circuit is very light duty indeed!

I flew a C-150 back in the '70s that had stiff ailerons which were thought to be incorrect rigging/too much cable-tension. The sprockets turned out to be the problem. Vibration and improper lube (someone had religiously used oil on them which attracted grit/grime) had worn the teeth to engage incorrectly. The difference could not be detected visually, but when compared to new sprockets, the "curve" of the leading-edge of the teeth were visibly different on the old sprockets.
Both the chain AND the sprockets were replaced and the problem was cured.

I have a lead on some sprockets to compare, but either the chain is too long or stretched from improper adjustment. If you could buy a new one from Cessna I would, but nobody has them which seems odd for all the different models that used them. I will know more this week. If anyone can take a good picture behind the panel showing the chain assy it will be appreciated.
Mike

If you have access to either a Grainger or a McMaster-Carr catalog, they have all kinds and sizes of roller chain and sprockets. I would strongly suspect that Cessna used some sort of standard sprocket and gauge of roller chain.

It might even be the same chain/sprocket as on blueldr's vespa.

FredMa,
I only wish the Vespa had a chain drive. Unfortunately it is a belt drive using what is called a CVT (Continuous Variable Transmission) drive as is used in a snowmobile. A really lousy setup for driving on pavement. My old Lambretta scooters from fifty years ago had a four speed progressive transmission which I consider a helluva lot better.

mike roe wrote:... If anyone can take a good picture behind the panel showing the chain assy it will be appreciated.
Mike

Let me know if you need measurements or more detailed pictures.

Gary
Thanks, thats great. I was concerned something was not right with the assy I have the way the chain made contact and rubbing on the the tube, and also the tube adjustment. The one I have appears the same. I am going to swap the sprockets and chains one at a time to see which is the culprit for making the tight spot. I am leaning towards the chain the way its adjusted proper one way but gets tight turning it to the limit the other way.
Thanks again
Mike

The latest is I ordered a 10 foot piece of Diamond Chain. So if anyone needs some let me know. Its approx 2 12in pieces required. I went on the Diamond website and found some measurements on how to determine if a roller chain is beyond limits.The chain I have is. I stated I believed my chain to be stretched which isnt good terminology. It is actually worn. I think the stetched came from my early motorcycle days among other things. Still waiting on a couple sprockets.
Mike