Enerjet by Aerotech Strong Arm Build, Part 6, Fit & Joining Two Tubes

On the left are the two tubes slid together using the coupler inside. No glue yet.

On the right is after sanding the tube ends square, the sanding shown below in the left side picture. Again, no glue yet.

Square up both tubes with a sanding block with 220 grit.

Slide the tubes together using no glue over the inside coupler.

Rotate the upper tube until you get the best, tightest join of the two tube ends.

Mark that best joint with a pencil line. When glue is applied, line up the pencil lines.