I own a CabMate machine and recently purchased a preformer for it.
Apart from a few pictures, the instructions for setting up the
preformer were sparse. I’ve done single cabs on the preformer and as
long as I’m watching it, I can stop it when the stone is the right
size. Recently I dopped five stones together and put them on the
preformer. I left the machine to grind away until I couldn’t hear it
munching anymore, meaning the cam had come into play. The cabs came
out the perfect shape, but too small. I ruined five pieces of nice
jade. This has happened twice now. I know what my mistake was. . . I
had the preformer too close to the center of the grinding wheel, and
the dop wasn’t dead center on the cut cabs. Is there a quick sure way
of getting the preformer lined up so that the cabs end up the same
size as the cam? Also, is there a way of making sure that the dop is
dead center on the cab? I thank you in advance for any help you or
anybody else can give.
David, I am not familiar with the CabMate preformer, but others I
have seen and used have a variable stop on them to adjust the size
of the stone. This is usually on the stop that the cam rides on.
By using this stop, you can preform numerous size stones with the
same cam. IE, if you use a 0-2 oval cam, you can cut a 3x5, 4x6,
5x7, 6x8 7x9, or 8x10 stone, just by varying the stop. In other
words, that cam will cut a stone 2mm longer than it is wide,
regardless of the dimensions of the stone. If you set the stop for
a 6.5 width, you will get an 8.5 length. This is how it works in
theory. With my hand crank preformer, I will usually end up with a
stone that is about 0.5mm short if I cut to the width. From your
description, the preformer has a motor drive and should give better
results. Look for the adjustment screw.
Don