Ranger Clone Build Part 12 TIP: Gluing Four Fins Without The Wobble

Three fin rockets are like a three legged stool. All three legs make contact with the floor and they never wobble.
Four finned rockets are like that chair around the kitchen table. One chair aways wobbles. I have made a few four finned rockets over the years that wobble when set standing on a flat surface or shelf.

To get rid of the wobble, glue three fins on and stop. Let those three fins thoroughly dry.

Put a line of glue down the root edge of the fourth fin as usual.
Your rocket might stand up on it's own on just the three glued fins. (Be ready, it can easily fall over.)
Set the glued fourth fin on the drawn fin line.

Stand the rocket on all four fins on a flat surface. The root edge glue on the last fin is still wet.
Slide the wet glued fin up or down the drawn line until surface contact is made on the bottom of all four fins. It won't take much movement up or down to even out the bottom trailing edge plane.

Be sure to check the fin placement at the top of the leading edge. Sliding the fin forward or backward might move the root edge off it's pencil line.