We used to make our speaker’s horns freehand!
Traditionally, my horns have been laid up by hand, free form, in the air. I let the geometry of the flat shapes dictate the octagonal form. This works well but it requires exquisite attention to detail.
The notion of making a clamping mandrel has been rolling around in my mind for a while. After months of finagling, this apparatus has proved itself worth the wait.
Sacrifices were made for the greater good.
The smooth sides of the form evenly support all the pieces in the correct relationship as they are assembled
Form fitting clamps are used to lock the pieces in place.
Adhesive is easier to apply to the seams using this form
Use of the Mandrel significantly reduces production time for the Bell assembly.
There is still the arduous surfacing and seaming of the finished Specimen Horn, but this fixture has been a great boon to the process.