Cad/cam correction

Doug Zaruba —as I sat at my bench polishing up my cad/cam castings
I th ought about my comment that their weren’t any tool marks from
the machini ng and I felt like I was a bit too overzealous in my
appraisal of the pro cess. The tool marks are next to un-noticeable
to the naked eye but they do exist… increasing the initial
resolution to something greater than 60 bits per square mm helps a
whole bunch; it slows down the process a lo t but if your concern is
tool marks go with that… I can’t see any with 90 degree cuts but
often use 88 degree cuts in an attempt to soften the overall look
somewhat and in those cuts they will crop up. Another solu tion is
to use some Stoddard solvent (contenti has it) its akin to wax s
hine and works pretty well. Some of the student complain the small
gives them headaches but it doesn’t bother me… smells like
kerosene … I us e it not so much for the tool marks (which I find
so so minimal) but to h elp with the cleanup of the waxes… I
alternate between ultrasound and S toddard solvent and a soft
toothbrush… another helper is to put a drop of baby oil on the
piece being cut… it feel like it makes cleanup a w hole lot more
of a pain (gunky wax dust compacted vs. dry wax dust compac ted) but
it does help with clean cuts. A final point is the quality of th e
cutting tool itself a lot of folks use a tool bit cut at a 15 degree
an gle; I have been using a seven and a half degree tool bit. Hope
this hel ps sorry if I was too flowery in my initial post. Mark
Kaplan @mark_kaplan