"Charley" wrote in message

I once watched a demonstration of a JDS Multi-router. It made great
mortices
and tenons, but getting a tighter joint fit required switching to a
slightly
oversized template to cut the matching tenon. They had over and under
sized
templates that they switched to whenever it was needed. This helped get a
better fit, but there were only a few over and under sizes available, so
sometimes the result was either too loose or too tight with no ability for
a
slightly tighter or looser adjustment.

Not exactly ... as with ANY router method/jig, sharpening a bit will change
the size of the routed mortise or tenon, as will using cheaper erratically
manufactured, damaged or excessively worn bits.

With the M-R, as with any router based "jig", template requirements are a
function of bit size.

The M-R has two tenon template sets, the standard set designed to be used
with precisely manufactured bits/endmills, and a master tenon template set
for odd/worn/sharpened bits.

The latter uses graduated "inserts", which allow you vary the size of the
tenon based on erratic bit sizes ... this is what you saw demonstrated.

Simply using the correct size bit, or endmill, precludes that necessity.

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Last update: 2/20/07
KarlC@ (the obvious)