1/2" tubes are used for the trim tab system. I used a 0.500" reamer, sanded the 4130 tubing. Way too stiff. Gently aligned out pivot with the tube, so it would match inner tube. Still too tight. Made a 'honing tool" just 3/8" rod with a slit for emery paper. Photo is me using a drill and moving emery paper back and forth to clean up the inner weld. Reamer didn't work as material is so slight. After an hour of polish the tube, reaming the slip fit, nice and solid fit and tubes can move.
Also started removing a little lead on those counter weights. One was near perfect (boards pinched in, so it used less lead to fill everything). Other side boards where thick. Forstner drill bit (1.5" diameter) works fantastic on lead allowing for light removal. Hole saw wasn't good (lead melts then seizes the hole saw).
Not shown... place a 1# weight approximately 7.5" after of hinge center line. Lead counter balance is correct when elevator (held by pivots) remains horizontal. Remove gross amount of weight with 1# about 12" out so you can 'sneak up on it' just keep moving weight a little at a time.
Honing the ID with a rod and some 180 grit emery paper
