On 3/11/12 1:24 PM, dpb wrote:
On 3/10/2012 8:22 PM, -MIKE- wrote:
On 3/10/12 7:34 PM, dpb wrote:
The planer won't do any good on cupping anyway; the feed roller
will simply press the board flat, run it under the cutterhead and
out it will come recupped when the pressure is removed.
I remove cupping all the time with my planer. I don't think it's
possible for mine to do what you describe. It would have to be set
too low and I wouldn't be able to get the boards started.
That must be an interesting planer design that somehow manages to
exert a forward thrust on the material sufficient to push it through
the planer and take a cut while not bearing down on the material the
same time.
Or, it's some other kind of wood than that which I can procure
locally that has an infinite moment of stiffness so it isn't affected
by that (nonexistant, of course) downward pressure.
How much, specifically depends on the thickness of the material and
what it is; nominal 1" white pine just ain't that strong; you can
flex it easily by hand. Run a piece of 3" roughsawn oak thru and
yeah, the deflection will be minimal.
--
There's barely any downward pressure and I assume that's the case with
most modern planers. I have a Delta 22-560 and the rollers are about
1/16" proud of the blades. It has a maximum cutting depth 3/32" The
cast metal casing of the planer sits very close to the the level of the
rollers. If I try to feed a board that is bowed enough that it would be
pushed down by the rollers enough to "spring back," the casing would
block the board from even entering the cutting area.
Here's another thing I've observed with most planers. There is very
little room in the cutting depth adjustment between "the rollers
grabbing and pulling the wood" and "the rollers slipping and not
grabbing the wood at all." This tells me that the rubber on the rollers
is doing the work of pulling, via simple friction, and not some
extraordinary amount of downward pressure.
--
-MIKE-
"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com
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