I've just started making a few cuts on my Grizzly 4x6 bandsaw and
must say I'm quite pleased with the results. I am cutting 303
stainless bar, 3/4" x 2". Although it might not be the suggested
orientation, I laid the piece flat so the blade started on the 2"
side first. The cut surfaces showed fine striations in the direction
of the blade travel. This was consistent through the whole cut and
probably due to extremely small variation in blade tooth set or chips
dragging in the kerf and pretty much expected. But this is my
question. When the cut is held to the light at some angles, there
appears to be a very definite "wavy" pattern in the surface. Think
of this as looking at a ruffled potato chip, 90 degrees to the
ruffles. The wave pattern is at 90 degrees to the fine striations,
with a "wavelength" of about 0.22" . Is this making any sense?
These waves can't be felt. What causes this? The rough bar as
received from the supplier also showed a similar wavy pattern but it
was obviously cut on a vertical saw on the 2" side first and
the "wavelength is about 0.75". Both ends of the bar show the same
pattern. The waves look more like plateaus followed by valleys and
can be felt easily. I was using the original blade as supplied, 14
teeth per inch at the slowest blade speed, figuring I'd get some
cheap practice, before ruining a good bi-metal blade. I think these
waves may be caused by some factor related to tooth pitch but I don't
know. Has anyone else seen this or know what causes it? Would I
still see this if I switched to a variable pitch blade? Any ideas?
Tom Jenks
