Some features of the new mouthpiece are: There is no danger of breaking the lips of the crucible by driving the wedge in too far; it also eliminates the possibilities of battering the ends of the mouthpiece, as with the wedge style; leaking around the mouthpiece and improper setting when taken off and replaced is less likely to occur.
Due to the width of the face, one mouthpiece is sufficient for a slug of any size. This eliminates the necessity for a special mouthpiece for display, which was necessary with the older models.
Before replacing a screw mouthpiece be sure to thoroughly clean the surface of the crucible and the back of the mouthpiece of all dirt and dross. Place a thin coating of red lead and oil on the back of the mouthpiece and place it in position. Tighten the screws gradually, beginning at the ends and working toward the center.
Metal Pot Adjustments
There are two pot leg bushings which fit over the vise frame shaft and project up into the fork of the pot leg. These support the metal pot and hold it in position to lock up with the mold. The position of the pot in relation to the mouthpiece is determined by four adjusting screws in each pot leg and bearing against the bushings. These screws permit the proper alignment of the mold and mouthpiece.
The holes in the mouthpiece, through which the metal passes to the mold cell, should align with the smooth or constant side of the slug, as this side of the mold always remains in the same position. When using the mold liners for the different points of thickness of slugs, the position of the mold cap changes. If the holes should align with the rib side of a slug of large size, when changing to 6-point slug the mold cap would cover the holes, thus shutting off the flow of metal and causing an imperfect lockup or imperfect slugs.
The two screws at the top and bottom of each pot leg are for the purpose of aligning the holes in the mouthpiece with the constant side of the mold.
To make this adjustment, remove the mold and take it apart. Clean thoroughly the mold and mold pocket. Leave the cap off and place the constant part of the mold back in the pocket with a 30-em left-hand liner and a constant right-hand liner in the mold. Remove the plunger pin for safety. Turn the machine until the first elevator rests on the vise cap. The mold should now be in front of the mouthpiece. Raise the first elevator, holding it up with a piece of wood, one end under the head of the slide and the other on the upper end of the vise automatic stop rod. Close the vise. Unlock the mold cam lever, move the mold disk forward by hand so the locking studs can enter the bushings. Turn the machine by hand until the mouthpiece advances against the mold. Release the two front adjusting screws a trifle so the pot legs can move freely while making the adjustment. Release the lock nuts and move the top and bottom screws until the bottom of the holes in the mouthpiece are in line with the constant part of the mold, and the two end holes are showing within the liners. Tighten the lock nuts and the front adjusting screws after finishing the adjustment.
A great amount of lockup trouble is caused by the mouthpiece on the metal pot not locking up squarely against the mold, due to the front and back pot leg screws being out of adjustment or the mouthpiece being warped.
To adjust the pot legs so the mouthpiece will lock up squarely with the mold, place the machine and the mold (without the cap) and the 30-em liners in the same position as when adjusting the height, but have the mold cam lever connected to the mold slide. Leave a little space between the mold and the mouthpiece. Place a piece of tissue paper at each end of the mold between the mold and the mouthpiece. Have the paper just inside the ends of the liners. Turn the machine forward until the pump lever is ready to go down for the cast. Be sure the plunger pin has been removed, to prevent accidentally forcing the metal out of the pot.