Fin Adjustment Tips

The Foundation

• Put the fin root on a flat surface.

– Trying to force the fin root to follow a helical contour can be ugly

Fin panel CL

Shroud

Foundation

• Epoxy or rivet fin foundation to aft shroud permanently

Plate Fin Panels

• Cheap plate fins are easy to build in aluminum & work fine – Just cut to the right planform & put a hemicylindrical radius on the leading edge– Need a leading thermal cuff for supersonic applications

Wrong way

Right way

• Plate stock is produced in a rolling mill

• Plate will have a small residual curvature

• Follow the above sketches for best results

Spindle & Collar

• Extend fin main spar to form a cylindrical spindle

• Adjust fin cant angle by rotating about spindle

• Retain fin panel with a removable collar

Fin panel CL

Shroud

Foundation

Spindle

Collar split or threaded on spindle

• Drive spindle rotation with two opposing set screws near leading or trailing edge of fin root

• Best design concept with built-up fin panels

Fin Foot

• Rivet or screw foot to fin panel root

• Attach foot to foundation with bolts in slotted foundation holes

Shroud

Fin attach screws

Foundation

Fin Foot