On 2/1/2019 10:26 AM, DerbyDad03 wrote:
On Friday, February 1, 2019 at 10:31:32 AM UTC-5, Leon wrote:
On 1/31/2019 3:10 PM, DerbyDad03 wrote:
On Thursday, January 31, 2019 at 3:38:18 PM UTC-5, Michael wrote:
On Thursday, January 31, 2019 at 2:19:30 PM UTC-6, Jerry Osage wrote:
On Thu, 31 Jan 2019 07:23:56 -0600, dpb wrote:

How long is the workpiece and how are you supporting it coming out the
backside of the planner? That sounds like it may be that the whole
workpiece, sled and all is causing the rear table to droop and raising
the back end up into the cutter head owing to the moment arm off the
rear table...these little guys aren't all that beefy, the table may well
flex, too, without additional support.

Even if the out feed table does not flex the board will try to pivot the
tail end up with the fulcrum at the outer edge of the out feed table.

Although the in feed and out feed rollers in my planer are not spring loaded
they will flex and deform slightly causing what may be a similar problem if
my out feed support is slightly lower than the planer bed. Somewhere in the
last third of the board it will develop a very slight taper as the weight of
the board starts pressing up on the feed rollers - and a bad snipe when the
end of the board passes the in feed rollers...
--
Jerry O.

Maybe an extended feed table or standing feed rollers will minimize the problem.

How about an extended feed table supported by roller stand on the in and out
feed side? That's what I've been using.


If your board has a twist or bow, as mentioned in another part of this
thread, a 100' long in feed and out feed will be of no help to
straighten/flatten the work. The work has to be supported where the
board bows up or twists up. I use small wedges between the
twisted/bowed work and a sled longer than the work.

Yes, I know that. I was simply responding to Micheal's comment about an
extended table by noting that I am already using one. While it, by itself,
does nothing to flatten the board, it does provide support for the sled.
When using a 6' sled and 8/4 boards like I am, it's nice to have a few feet
of solid support before and after the planer instead of relying on the
relatively short planer infeed and outfeed tables.

OK, ;~) Actually I have a 15" stationary planer with fold up/down in
feed and out feed rollers/tables that are about 2' long. They work just
fine and I do not worry with them being on the exact same plane as the
planer bed/table.

FWIW the sled you have and the one I am talking about are completely
different. My sled travels through the planer at the same rate as the
work. I use the wedges to keep the work from moving up or down, because
of bow or twist, between the sled and the work.





As shown below, I am using an extended table for support and a sled for the
actually flattening process. The only thing not shown in the image is the
shims/wedges. Rest assured that I am shimming the boards solid to prevent
rocking and flexing. The image is just an example of the set-up in response
to dpb's request to see it.

https://i.imgur.com/fSSwztH.jpg


The in feed and out feed rollers are not intended to flatten a board
into submission nor are they in any way instrumental in flattening a
warped/twisted, or bowed board. They simply push or pull the work
through the planer.

Agreed. But is it possible that they could *screw up* the flattening if they
were misaligned or applying uneven pressure?

No, as long as they are in constant contact with the work, preventing
the work from lifting.
You have a constant indexing point, the bed/table of the planer. As
long as the cutter and bed are parallel to each other there should be no
issue with screwing up a cut. Think of ripping a board on your table
saw. You have the constant indexing point, the fence, that keeps the
distance between the blade and the fence constant. Your hands, that
work like in feed rollers, contentiously apply "different" pressure as
you feed the work. This done properly does not affect the width of the
cut.

IF the in feed and or out feed rollers are high or low on one end the
cut will remain the same as long as the cutter and the bed of the planer
are parallel. A high or low, on one end, in feed or out feed might
cause the work to not go straight through the planer as it feeds but
that does not normally affect the thickness of the cut either. It is
seldom that boards go straight through a planer.




That is basically been the question that I have been trying to get an
answer to.