I read through all of the replies so far. Hmmm.....
OK. There's lots of folklore and pukey plastic gadgets surrounding
this topic and I think most of them have been mentioned so far. I'll
start by elaborating on them.
1. Having a dial indicator will make the task extremely easy and
accurate, but buying a "SuperBar" and a "MasterPlate" won't help in the
least. Only the last photo on the Woodshop Demos page addresses the
miter gauge. However, the technique demonstrated doesn't really
require either of the products. In addition, the technique (which is
widely accepted as accurate) isn't guaranteed to provide good miter
gauge alignment (see Myth #3).
2. There is no guarantee that the miter slots are square to either the
front or rear edge of the table. So there is no guarantee that butting
the face of your miter gauge against them will result in accurate
alignment. If it isn't a square, and it didn't come with a squareness
specification, then don't trust it for machinery setup.
3. Using a square between the blade (or blade replacement plate like
"MasterPlate") and miter gauge face does not guarantee square cuts.
The angle of the cut is defined by the orientation of the board
relative to it's motion, not relative to the surface of the blade.
Motion of the wood in this case is defined by the travel of the miter
gauge in the miter slot. Squaring the miter gauge up with the blade
surface might work if the blade is really flat and carefully aligned to
be parallel with the miter slot. These two dependencies make the
practice dubious at best. You really don't want to have to check blade
alignment and flatness every time you square up your miter gauge.
4. Cutting up a bunch of stock to check squareness is (in my opinion)
wasteful of time and money. Two methods were proposed (the "cut and
flip", and the "four consequetive cuts"). Yes, they work. I just
can't bring myself to doing it. I'm sure that people with a lot of
free time and wood who would disagree with me. I don't think they fall
into your qualification of being "quick".
5. Having a sled doesn't guarantee that it produces square cuts. It
needs alignment too. I've done some amazingly accurate cuts using my
miter gauge and it's the stock POS that came with the saw. Still have
it, still use it, haven't seen the need to buy a fancy one.
6. I don't trust stops. First, they have to be properly set up so you
don't get away from the whole alignment issue. Second, they flex and
are prone to error from a number of sources (sawdust, etc.). They are
really handy for general, low accuracy work, but it sounds like you are
looking for something more precise.
So, what is a quick and accurate way to ensure square cuts with a miter
gauge? All it takes is an accurate square and a measurement device. I
prefer a dial indicator because it's cheap, easy, accurate, and quick.
However, you can use anything you like - including a subjective "feel
the rub" or "hear the scrape" measurement technique (if you happen to
be proficient at it). It's a whole lot easier to show a picture (or
demo) than to describe:
Open the TS-Aligner Jr. User Guide at
http://www.ts-aligner.com/tsjrman2.pdf and go to p.27.
- or -
Watch the "Table Saw" video at http://www.ts-aligner.com/videos.htm
starting at about 10:57 into the clip.
This method is independent of all other saw adjustments and absolutely
as accurate as your square. It's not completely foolproof but pretty
darn close. Let me know if you have any questions.
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