I recently bought a variable speed benchtop Delta 6" jointer. While
reading the instruction book (well - someone has to...) It says that
the thinest wood edge that should be jointed is 1/2".
Can anyone explain why? I wouldn't have thought that a board could be
too thin. If I have a 4" wide 1/4" thick board against the fence (the
4" against the fence, the 1/4" against the jointer blades) why should
that make a difference?
What am I missing here?
That there is an *error* in the manual. <grin>
I bought the same jointer last summer. I'm infamous, locally, for always
reading the entire manual on -everything-. (I don't necessarily -follow-
it, but I always read it :) Had to call tech support about something else,
and, -- since I was on the line anyway -- *asked* about that very thing.
The phone person didn't know; went off and asked a real engineer; came
back and said "it's mis-written". 1/2" minimum from the bed to the 'top'
(i.e., the 'furthest away from the bed' surface) of the board.
The safety concern -- above and beyond running fingers into the cutters -- is
that the board might flex 'into' the cutterhead, with the knife digging in,
and snagging the wood. Not kickback, but dragging the wood _down_ into
the works, as it breaks above the cutterhead.
email@example.com (Robert Bonomi) wrote in
That, and a 1/2 thick board might slid under the guard and get hung
up under it, rather than pivoting it aside. Which tempts the user to
tie the guard out of the way, and then of course the cutter isn't
covered after the board passes by.
You can joint any thickness you want . But what the manufacture is worried
about is "tear out". The thinner you go the more you get, if you do not
aline the grain. So that is why they have a min thickness.
The instructions were referring to face jointing a piece, not edge jointing.
Personally I'd consider 1/4" the maximum thinness (?) and then only with a
feed block, but then I've never used a a bench top jointer.
If they should actually mean edge jointing the only reason I could think of
is that after a certain point, when edge jointing, the wood is so thin the
cutters just tear the wood off the edge rather then shaving it off. This
leads to a messy edge and the possibility of the piece being torn from you
hand. Again though I would think 1/2" would be a bit thick for a limit.
Sorry, Mike! (Something's fishy here, your name should be Charlie, for that!)
In two successive paragraphs, they say you should not face joint anything less
than 1/2" thick, and then they say you should not edge joint anything less than
There's a simpler explanation. Tech support said its a _mistake_ in the
Yup. you set it according to the type of wood, and the width of the
material hitting the knives. range of speeds is about 3:1.
It's really easy to alter the feed rate on a jointer to vary the cuts
per inch. I don't know why you'd change the speed depending on width
of material at all. Does you manual give an explanation for different
speeds for different material widths?
I appreciate the responses - about 1/4 of you understood what I was
asking. Not only is my woodworking crappy, so is my writing. However,
to the questions:
1. Actually on looking closer at the manual the narrowest edge that
can be jointed is 3/4" not 1/2". And yes, that's narrow *edge* down.
In other words if I'm jointing a board 8" wide, 4' long and 1/2" thick
-- I want to put the 1/2" thick part against the knives.
2. Several people asked about the variable speed. I don't know if it's
a marketing gimmick, but there are five settings from 1=6,000 rpm to
5,000 rpm (knive rotation speed.). The chart lists plastic,
softwood, and hardwood of widths ranging from 0" to 4". Basically the
narrower the material the slower the rpms are supposed to be set.
P.S. And to Robert Bonomi who seems to be the only one who completely
understood what I was asking - thanks.
Well, either the rest of the crowd doesn't have _that_ jointer, or
doesn't read the manuals. <grin>
i _do_, and I _did_, and encountered -exactly- the same 'confusion'. Thus,
when the opportunity presented itself, I queried the manufacturer. I believe
that section of the manual is re-written for the next printing.
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