I was faced with a bit of a dilemma. I didn't want to just weld a nut on the end of the trim drive arm for the rod end to screw in. There just aren’t enough threads to hold the rod end securely. So I had a number of options and I picked two. One option was to take a piece of .049 1/4in tubing and insert that into the end of the 5/16ths .035 after reaming that out, rosette weld it and then tap the end with a 10-32 tap. I didn’t like that there was a ridge inside the tubing after reaming and a crack may appear at that spot later. I chose option two, and that was to take a solid piece of 7/16ths 4130 rod, drill the hole using a no. 21 drill through the middle for the rod end. Then use a 5/16ths bit and make a 3/8ths recess in one end. Turn down the piece so it has enough to weld on the rod end and taper to have enough bearing surface for the lock nut on the rod end. The wide end ended up being about .400 and the narrow end about .340. The 5/16ths trim tubing has enough to weld to the end and the rod end has more than enough threads for a good, strong connection. I can even trim down the narrow end about 1/4in and still have enough thread engagement. Tomorrow I’m going to bring the pieces to an A&P friend of mine to find out if he would recommend a rosette weld in addition to the weld around the tube. Also I need a distance to drill a small witness hole in the end to ensure the rod end is screwed in deep enough for adequate thread engagement. Whew! It was fun doing this, but may be a bit of overkill. I know it will be right when it’s done. The last thing I want is the trim coming loose at the worst possible time.
