Two plates, four prongs

Saw a slot halfway into two plates, push them together into a cross and solder. Saw a V from the side, file a V in the middle for the pavilion and cut a seat in each end: the four ends become the prongs.

Crossmaker works out the plates from the stone and the sheet, and checks that the prongs will hold.

What it does

• The stone – a round faceted stone of any size, with crown, girdle and pavilion.
• The plates – two plates for four prongs or three for six, the sheet, the metal under the culet and the width of the foot.
• The prongs – the metal behind the seat, the depth of the seat, the height above the girdle and the width at the tip, with one button for sturdy prongs for the stone.
• Will the prongs hold? – warnings for thin prongs, deep seats, short or tall prongs, wide tips and a weak joint.
• Templates, 1:1 – one per plate, with the blank, the slot, the girdle line and a 50 mm ruler.
• Step by step – from the blanks to pushing the prongs over.

Beta

Crossmaker is new. Check the first print against a ruler, and the plates against your stone, before you saw.