Hi Bob;

     Going backwards, I use some surplus .027" flying line for lead outs. This is plenty big for just about anything you would be building. If you know anyone that used to fly large scale models, they may have some they don't need any more. I don't use solid lead outs any more because I hate having them hang up on stuff while handling the model

    Sparky  (Bob Storick, the owner of this forum) has a YouTube channel with just about anything that you nay want to know in a video format. The old Windy Urtnowski Pro Stunt Products videos are being converted to digital and are uploaded to YouTube also. Fred Cronenwett has some videos on this subject also on You Tube.

    There are several different sizes of thimbles available. The ones you have may just be too small for that cable. Try some larger ones if you have them. The copper tube trick just requires soft copper tubing that is just large enough in the ID for the cable to go through it. You want the over all length of the cable end to be about 1 to 1 1/4" long so cut a piece of tubing about twice that length. Take a length of the cable and thread it through until it comes out the other end. Mark the middle of the tube, and carefully start to work it around a smooth, round object right at the middle mark. What you want is sort of a tear drop shape in the end. Before you go too far, but at least have it in a distinct U shape, thread it onto the lead out with about 1 1/2 " sticking out the end. Work the tube into the finished tear drop shape where the free ends are laying right up against each other and as they go towards the middle mark, that start to form the loop. Have some kind of hard metal rod or something about 3/8" dia. to help form the loop. Take some soft copper wire and start wrapping the cable from the ends of the tubing and go out a little more than half the distance of the loose end of the cable. Then lay that loose end and lay it back over that section you just wrapped and wrap what is left going back towards the tube. When you get back to the tube, tie off and secure the end and snip off any excess. Don't solder anything, it will be fine just as it is. I haven't seen a Morris bell crank in along time, but this may be the method that he used to make his bell crank lead out terminations, and if so, you have a perfect example right in from of you.

    There is quite a bit of this on the forums, including pictures. There is SO much information on the forum that you need to be kind  of specific with your search words now. Keep practicing with the search function as you go along. I am of the opinion that there are NO new problems in the hobby, and most things have been covered several times over the 20 years or so that the forum has been in existence.

  To quote Bruce Willis, "Welcome to the party, pal !!"
 Type at you later,
   Dan McEntee

Bob,
I have good luck using annealed brass tubing of 1/16" OD and 0.027" leadout wire.  I think that I use either 1 3/4" or 2" lengths depending on the size of the teardrop I want to make.  Wire should still slide freely through the tubing until you wrap it down.  I have also used copper tube of the same diameter, again annealing and then sanding to clean up before bending.  Dan's description pretty much covers how I have done mine (at both the bellcrank and connector side) for quite some time now.  Good luck.
John