Ok, I'm back to the project. Going to start with pushrods and ball links. We have all heard stories of ball link failures. I think most occur from failure of the ball link itself in the threaded area or in the attachment of the threaded end to the carbon fiber pushrod. I'll review how to keep both from becoming a failure looking for a place to happen.
First the threaded insert should fit passively into the carbon fiber tube. If it doesn't, don't mess around, buy another tube. If you force it you will cause mircro fractures and it it will sooner or later fail. You can if you want sand the insert down til it fits if you have a tight fit. Be my guest. I don't care to sand anything that hard, but then I hate sanding and I keep a supply of different sized carbon fiber tubes on hand so replacing the tube is easier for me. If you have a tight fit you will have a failure.
Next you would like to anchor the components not just with adhesive, but mechanically as well. I showed this on the T-rex thread and will just touch on it lightly here. I do this buy drilling two 1/16 inch holes thru the tube at 90 degrees to each other. When the adhesive is placed into the tube and around the insert and the insert pushed into the tube you should see adhesive come out of the holes. Actually you should see the adhesive come out of the holes before you place the insert. Its how you know you have adhesive in the tube. The adhesive is placed on a pad after mixing and the tube scraped into it with the tube at about 45 degrees to the pad and pushing the open end of the tube into the adhesive while it scrapes over the pad. If you have never done this you will be surprised how far up the tube the adhesive will be forced. Also you want to coat the insert and its hollows with adhesive so the hollows are filled in. Then push the insert into the tube. This will result in lots of excess, wipe it off with a dry towel. Do not use acetone or any solvent, you will weaken the epoxy. While on the topic, two adhesives work. JB Weld is the most common used and best recommendation unless you have a lot of epoxy experience. A structural fillet blend done at lower viscosity than normal fillet blend will also work well. The metal should be cleaned with solvent like dope thinner, acetone, mineral spirits, etc and ditto the inside of the tube... not so easy to do. pipe cleaner will work. You need to be thinking ahead so that can get a heat shrink over the end of the tube and insert as well. This is a fall back that aids in preventing a spintering failure of the tube. Not likely to happen if you have a passive fit to the insert, but its just a redundancy I like to have.
If the bonding is done this way you will have the entire space between the insert and the tube filled with no voids with the adhesive and the adhesive will be locked mechanically and chemically to the tube. The first pic shows the hole, pins are thru them, and the second shows the end result after the heat shrink is shrunk. If you look carefully you can see where the adhesive extruded thru the tube by the bumps in the heat shrink. Also the heat shrink makes a smoother contour at the head of the insert so it does not catch of a bulkhead or something. I of couse would never build anything that had the senario but that jerk Murphy is always tampering and modifying things in the shop when I'm not there so I just try plant traps for him.