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.

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?

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