When you're cutting a centered groove on a workpiece, and are sneaking up on a
certain width, do most of you align to the outside edge of the blade and bump
the fence away from it, or do you align to the inside edge and bump the fence
towards it? My boss basically implied that I was doing it wrong by aligning to
the outside edge and bumping away from it - but didn't really elaborate.
My way is better. Just because.
For years I have done it both ways by accident. I see no difference either
THAT SAID, I do make the adjustment while the blade is spinning and prefer
to adjust the fence away from the spinning blade rather that towards the
If I understand you correctly, and because of the built-in backlash in my
fence mechanism, I align the initial cut to the outside edge of the blade
and bump the fence away from the blade for the second cut, thereby making
the cut wider toward the fence side.
That said, the best way I've found to precisely _center_ a groove/dado, is
to do the math and set the fence as precisely as possible, then run the
piece, flip it end for end, and run it again ... that guarantees a centered
groove. I can generally get the width precisely this way with one or two
test cuts, and then proceed without having to move the fence again.
Hope I understood you correctly.
Every time I hear Norm advocate this I want to scream "Yeah it's
centered but it's wider, too!" As usual. he never explains how to set
up a cut, just how to push the wood through.
So are you making test cuts until the dado quits getting wider?
Easier to do than explain. Set the fence so that the first pass is
_slightly_ off center in a piece of scrap the same width as your workpiece.
Flip the board around and run it through again. Now tweak the fence setting
until the two successive passes cut the desired width. Same with router bit
or dado stack.
You obviously need the blade, bit, or dado stack to be narrower than the
desired width of your groove ... half, or a rch more than half, works well.
Use this method when you want to precisely center a groove in the width of
It doesn't matter. Cut the dados first and the tenons second. One rarely
needs an exact 1/4" dado - just a close approximation. (I'd also comment
that Norm's centering of the dado isn't required either as long as the
face of each piece is oriented the same when the dados are cut.)
Owen Lowe and his Fly-by-Night Copper Company
Offering a shim for the Porter-Cable 557 type 2 fence design.
Well, in many cases this sorta does matter. I build lots of cabinet doors
and most have a 1/4" plywood panel centered in them. For a good fit, the
dado needs to fit the panel snugly but not too tight. After that is
accomplished cut the tennons.
As far as centering the dado, that just makes every thing a lot easier.
Cutting the tennons is much easier if the dados are centered as you only
have to determine the depth once and cut both sides at the same time.
I personally use the regular saw blade to cut the dados. A pass in each
direction is all that is needed once the fence has been properly adjusted.
I'm not sure i quite understand your description but... I make the
first pass as near dead center as possible, run the piece thru,
reverse it and run thru again. Now I have a perfectly centered groove
- if it needs to to be enlarged it matters not which way the fence is
moved as long as you make 2 passes reversing the piece for each pass.
The downside is that each movement of fence causes the groove to
enlarge by twice the fence movement.
Enlarging the groove wastes less wood than making it smaller. Take an RCH
less than half the required, tuck the fence and lock, make a sneak end cut,
check what you did, do what you need.
Truth is, I use the board width minus groove method to start setting the
fence, making it favor less.
That's the thing about bosses, they can do things like that and, if they are
so minded, make it stick.
In other words, it probably isn't going to really matter how you or anyone
else thinks it should be done..
When I cut a cetnered groove I set the blade around the center of the
piece, cut it, turn it around and cut again. Measure the fit and bump
the fence away from the blade to adjust. I always go away from the
blade just because I am used to it and it is AWAY, not TOWARD the
blade which just has to be safer in the long run.
If the fence is not flexing and the wood goes through straight, there
is no difference in terms of accuracy between bumping to or away from
the fence. Of course, if the fence is flexing or the wood is not
straight going through the saw, neither method will be accurate, or
Jay Pique wrote in message:
My boss basically implied that I was doing it wrong by aligning to
Sorry, boys, the boss is right.
Your cut is always between the fence and the blade. By marching your
fence away from the blade, you are leaving an invisible cavity, inside
the workpiece, and between fence and blade that could allow the
workpiece to float out of the cut; your groove will be imperfect.
Also, your fence mechanism, if it includes a tape readout, whatever,
is adjusted to the inside of the cut, or blade. Your accuracy in
adjusting the cut is read from this perspective.
Nonsense -- it's the fence, not the blade, that guides the wood.
If the workpiece can "float out of the cut" then you're not holding it against
the fence properly. And if you don't hold it against the fence properly,
you're inviting trouble, *regardless* of which side is doing the cutting.
Note that this is true *only* on right-tilt saws; I don't recall the OP
specifying which type of saw he was using.
Doug Miller (alphageek-at-milmac-dot-com)
Get a copy of my NEW AND IMPROVED TrollFilter for NewsProxy/Nfilter
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You must use your REAL email address to get a response.
If you are allowing the wood to "float" anywhere, you won't be
woodworking long enough to worry about the fence position anyway. The
repeated thuds in your ribs and potentially other more sensitive areas
of the male anatomy will have long ago caused you to seek a less
Featherboards, or simply paying attention to what you are doing (both
hopefully) will produce a dead-on centered dado every time regardless
of which way the fence is moved. If your wood is floating, well don't
worry about the dado, DUCK!
God, I love the wreck...
the pissants are thicker than the mosquitoes this year.
Let's just forget that I have been working wood longer than either of
you has been alive, and have stepped up to the table saw some ten
Simple physics and your own common sense, if you have any, should lead
you to conclude the proper proceedure...do you hold a pencil with one
The fence on one side, the blade on the other...this is a pincer that
controls the cut.
Stick to your computers, boys; as woodworkers, you are a pair of
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