: Then the Right half of the brain starts in with "you really didn't measure
: anything. Simply the distance between the cutting point of the teeth and the
: corresponding point on the fence." The Left half, denied the assertion for
: a few minutes and then tried the ad-hominem attack.
Right hemisphere wins.
: The Right side responded with - "all I can know (surmise) is that the fence
: does not deviate towards the plane of the blade - since I haven't had any
: kickback incidents. It could still be out of parallel, but deviate away from
: the blade plane. Or it might be parallel. My experiment was inappropriate!"
: A few hours later, after the electroshock induced migraines left, I started
: wondering: does it matter, do I even care? My rip test indicates that I get
: a consistent width when using the fence and that's all that matters,
: Ignoring *kickback issues*, would I care whether the fence is parallel with
: the plane of the blade?
Well, you don't really want to ignore kickback issues to begin with, and
proper alignment of the fence is important to avoid that.
But otherwise, if your fence is out of parallel with blade, then the wood
(during a rip cut) is going to get cut more roughly than if it were
travelling parallel to the blade. And secondly, you aren't going to be
able to get consistent width of the rip.
Ed Bennett (maker of the TS Aligner Jr) recommends less than .005"
deviation front to back. I'm not sure how a deviation from parallel
affects width of the ripped stock, but your piece of MDF has a .008
difference in width, and you can get better than that, I imagine.
The TS aligner is a really nifty tool. I spent some time on Monday
aligning my new cabinet saw, and was able to get the blade parallel to the
miter slot by .002", and the fence parallel to the miter slot by .001".
They weren't out much to begin with, but it was nice to get it fine-tuned.
-- Andy Barss