Planing a warped board

[myxpykalix]

I've tried using the bot, tried using my jointer and never could get it right without a whole lot of work but this guy showed a way to do it on the jointer in 2-3 passes. From what i can gather, it really amounts to pushing down from the center while balancing it as you push it thru to hit your hi spots on the head and tail of the board.

https://www.youtube.com/watch?v=axbsL2nZC2M

I have done something similar on the bot where i measured the height of the warp on each end, divided that in half and stuck popsicle sticks under each side to balance it, then planed it on the top. That took a long time, lot of air cutting and shallow cuts. Not worth the effort or time.

[jTr]

Jack,
Depends on size of board. Rule #1: If it fits my conventional machinery built for this task, go there. Only hit the bot with over-size slabs that I really want to keep 100% intact. I've told myself I actually own a 5' wide planer in the shopbot, to an extent, though time is the price to pay with the cnc process.

While I agree with Bob VanDyke and respect him as a leading instructor and builder in the woodworking community, I tend to stay away from the center of any board I'm jointing. Too much tendency by the operator to press too hard in the middle, reducing the arc through pressure vs. allowing the machine to whittle high spots in the truest sense. If too much pressure is applied, the board simply springs back towards a bowed shape. This is why a jointer is where you start. If fed directly into a planer, feed rollers press the arc down, leaving the board to spring back as it's fed back out and feed roller pressure is released.

Seems a jointer should really be called a planer, as it's basic function is to establish a board with a true flat plane. A planer could easily be referred to as a surfacer, as it is really just completing the process of cleaning the faces after a flat plane is established by the prior process.

I typically determine the two high ends of the board and just be sure to place pressure there as the board is being jointed. On the starting edge, paddle is pressed on high corner and held there to keep that first hit as the standard of register. Hopefully, the board is short enough that I can ride that leading end of board and catch the tail end's high spot before leading end passes end of the jointer's out feed bed. This is the most effective way to get a flat established. I admit, my "cheat" is having a 10" jointer with 42" of out feed table, which means typical cabinet length boards can easily be done this way.


However, when lengths exceed the out feed table length, ride the first flat as long as possible, then shift to the tail end's high point. As you progress, the freshly trued ends grow toward the center, and you'll hit that pivotal point where you are bringing those two flats into unison. This will be directly linked to the length of out feed table.

Hope that makes sense. Again, Bob's method in the video is not flawed, I just get it done in a slightly different fashion and prefer to stay off the center of a bowed board, as that is the rule for 90+% of the time processing lumber at that machine.

jeff

[chiloquinruss]

I've got a killer planer BUT when I use its feed roller adjustment to feed the board through it needs to be tightened so that it forces some of the cup out. So lately I just push it through the first couple of passes, each side of the board until its 'close'. Then I give it the full treatment. Fortunately most of the time its in the width and NOT the length of the board. Russ

[Chuck Keysor]

Nice video Jack, thanks for sharing. But there was a big problem with the presenter's terminology.

He called flattening the face/wide surface of the board, "face jointing". The operation he was performing is called planing!

Jointing is creating a flat surface on the narrow edge of a board, which is exactly perpendicular to the broad face of the board. Check out Wikipedia's definition: https://en.wikipedia.org/wiki/Jointer Most significantly, jointing is what you do to the edges of boards, so that you can glue them together to make a big wide board without gaps where the board edges touch.

And Jeff was right in questioning the terminology used in the video when he said: "Seems a jointer should really be called a planer". But the real point is, a jointer IS a jointer, and a planer is a planer. And in the video, the teacher was using a big version of what I have in my shop, a "Jointer/planer". It is called that because it both joints, and it planes.

But over-all, it was still a good video! Thanks, Chuck

[dlcw]

I place the slab/board on the table crown/warp UP. Any area where the board doesn't touch the table I use shims to make it solid against the table. Surface the top side. Turn it over and surface the other side. Because the first side is perfectly flat, from step one, it sits flat on the CNC table.

Using this process gives me a perfectly flat and even thicknessed slb/board. After that I use belt sanders, ROS's, scrapers and hand sanding blocks to smooth it.

[chiloquinruss]

"table crown/warp UP" I do the same except my planer has a feed roller that takes a fair amount of pressure to move the board through the machine. That is why the initial couple of passes are 'hand fed'. It is an older machine and I think when I get a chance I will rep0lace the table with something a little 'slicker'! ;) Russ