How To Do The Twist??

Unless you need to preserve the length, the first thing to do is cut the board to length.  Or even rip it.  Smaller pieces will have less twist.  Either way what I have done is place the board on a flat surface.  Shim the two high corners.  I have used wedges carefully cut to fill the void along the edges.  Then run it through the planer with the wedges down.  They must be fastened securely with double stick tape or glue.  Then turn it over and plane off the wedges.  It's easier if you have another board or pieces of MDF to fasten it to and run the whole thing through the planer.  I keep a cheap melamine covered shelf for the purpose.  You can use hot glue and remove it with alcohol.  If you use the shelf/sled you can use a bunch of little wedges a few inches apart to support it.

You can also Remove the guard from you jointer and face joint 6" of it  and then attach a flat board to that surface and run it through the planer, flattening the other side.  Then remove the caul and flatten the remainder of the first side.

And you can lay it on a flat surface and scribe the two contact points and knock those off with the power plane.  Once that side is reasonably flat, run it through the planer with that side down and the flip it.  In all cases I find taking very light passes with the planer helps to keep it from mashing the piece flat and then letting it spring back.

(Just got a 12" Jet jointer planer combo machine and used it for the first time today.  Now it seems I have lots of 14 and 16" boards.)

Thanks, Barry
I've used sleds/wedges on smaller stuff, usually with the Performax.  Just have an issue with hefting an 8'+ sled and keeping it level.

I understand.  I am making more and more use of roller stands on both infeed and out feed.  On my Performax I made roller panels for both ends.  (Scavenged a bunch of rollers out of an ancient treadmill and made three panels with about seven rollers in each.)  I also see  conveyors at freight auctions, sometimes the expandable ones and I have not bid on them but it's almost irresistible.
I was using my new to me jointer planer today and it was almost more than I could do trying to flatten 9' long 5/4 oak boards 10 and 12" wide.  The tables are too short.  Probably should have bought a 12 or 16" long bed jointer.  I just don't have the room.  Had to roll this machine outside to use it.  One piece got away from me and flew way over there.  Note to self, stay out of the line of fire.  Nest time I will have to set up better rollers or get help.

Barry, I'm living proof that you can make an outfeed table for a short-bed jointer that will work for pieces at least 12' long. I had the same trouble with my first Inca jointer-planer, and I built an outfeed table (with adjustable-height feet for my crummy basement floor) that gave me laser-straight outfeed on long stock. Worth a try.

Ellis

Here is how I would approach milling that twisted 5/4 walnut board to get it flat and parallel with maximum thickness preservation using those tools:

1. Joint one face using the jointer. Take light passes to remove the twist while keeping the board as thick as possible. This establishes a flat reference face.

2. Run the jointed face over the planer to flatten the opposite side parallel to the jointed face. Again, light passes to remove minimum thickness.

3. Determine if there is still any remaining twist by checking with winding sticks. If so, pick the concave side and run through jointer again.

4. Once both faces are flat and parallel, smooth and remove any remaining thickness variation using the drum sander. This allows you to remove just the high spots rather than entire surface.

5. Check for square by measuring diagonals. If needed, edge joint one end on jointer then rip to width on tablesaw referencing from jointed edge.

6. Confirm final thickness and smooth/sand faces in preparation for use.

The key with twisted boards is to remove just enough thickness in each step to correct the twist, rather than flattening by thicknessing an entire side. Go slowly and check often to preserve thickness. Let me know if you need any tips on specific operations.