Tuesday, July 6, 2010

Fitting Control Horns To Tubes

To fit the tube/rib which the horn is welded to I needed a small jig. I added this to my elevator jig with 2 supports for the tube and 2 bolts to locate the cable holes on the horn. This assures the tube and horn are perpendicular to each other when welded. I located this over a hole to allow tack welding on both sides.

The first half of the horn was mounted in the jig with wing nuts to hold it in place. Notches for the tube we nibbled and filed until the tube just fit snug. By stacking this piece on top of the second piece it could be marked to more quickly nibble it almost to a finished cut. Then it was filed to a good fit.

The finished shells are clamped together ready to edge weld them. They will then be placed in the jig and the tube tack welded in position. This assembly can then be placed in the jig which has been setting for months and the entire elevator tack welded.

The steps in forming the horn parts are shown in this picture, form block, formed blank, trimmed blank, and finished parts ready to weld.