Shopsmith Forums

I thought that when you have a board with an arch in it that you need to joint, the top of the arch should face the ceiling. This page recommends the opposite technique. http://wunderwoods.wordpress.com/2012/0 ... ow-method/

Has anybody ever tried it this way?

He makes a really good case. i just got done doing about 80 feet of two by material to clean it up to glue it back together. Most of the problem was cupping not bowing. I will try this in a few weeks.

An interesting approach!

Not enough information regarding the workpiece though.

Grain direction/reversal . . . not input.

Typically I would chop on both ends(concave down), then proceed as 'normal' once fresh surface on both ends was riding on the infeed table. Only works on short or almost straight stock.

If I were to go convex down, I would first scribe a straight line and nibble close to it then proceed as normal.

All depends upon the 'board'.

"Normal" procedure only works on almost straight workpieces.

I agree with him that most folks think there is not much to 'learn'. After all the machinery is making it easy. All one does is push it through!:D





Technique, Technique, Technique!

JPG40504 wrote:An interesting approach!

Not enough information regarding the workpiece though.]first scribe a straight line[/B] and nibble close to it then proceed as normal.

All depends upon the 'board'.

"Normal" procedure only works on almost straight workpieces.

I agree with him that most folks think there is not much to 'learn'. After all the machinery is making it easy. All one does is push it through!:D





Technique, Technique, Technique!

I've always had trouble at the jointer working with pieces that are bowed, which is why I posted this. But your comments about scribing a line got me thinking. Maybe automatically going to the jointer with a bowed piece is the wrong approach altogether. Why not scribe a line (or snap a chalk line) and take the board to the band saw? Free hand it close to the scribed/chalk line to get the bow out and then take it over to the jointer to finish up? Seems like that approach is likely to conserve the most wood.

algale wrote:I've always had trouble at the jointer working with pieces that are bowed, which is why I posted this. But your comments about scribing a line got me thinking. Maybe automatically going to the jointer with a bowed piece is the wrong approach altogether. Why not scribe a line (or snap a chalk line) and take the board to the band saw? Free hand it close to the scribed/chalk line to get the bow out and then take it over to the jointer to finish up? Seems like that approach is likely to conserve the most wood.

Sounds good as long as no wind(twist)!;)

The line/bandsaw would work on the opposite face as well(cut each end).

We need to not lose sight of the 'main' purpose of the jointer is edge jointing, not face flattening. Hand planes do face flattening better(with practice!).

If the wood length is short (say 4+feet or less) you can get one edger, either edge started with a jig like this:

https://forum.shopsmith.com/viewtopic.php?t=11262

Once you have an edge cut if might not even need jointing. The cut edge is then used against the fence to produce a parallel edge. In most cases I find this a lot easier then any other method.

If you need more details on how this would be done with this sort of jig please post the questions on that link.

Ed

If a board is cupped and the jointed with the crown of the cup down on the jointer the board could rock back and forth. If the crown is up the board is set firmly on the jointer and the surface produced will not have variations.

In fact I can envision jointing the board with the crown of the cup on the jointer and making the crown worst.

First pass the board is rocked on crown so the left side of the board in pressed on jointer. Next pass the board is jointed the same direction but this time the board is rocked so the right side is pressed down on the jointer.

Think of trying to joint a V (extreme). Versus a ^ which one do you think you would have the better chance of holding he same every time?

Ed in Tampa wrote:If a board is cupped and the jointed with the crown of the cup down on the jointer the board could rock back and forth. If the crown is up the board is set firmly on the jointer and the surface produced will not have variations.

In fact I can envision jointing the board with the crown of the cup on the jointer and making the crown worst.

First pass the board is rocked on crown so the left side of the board in pressed on jointer. Next pass the board is jointed the same direction but this time the board is rocked so the right side is pressed down on the jointer.

Think of trying to joint a V (extreme). Versus a ^ which one do you think you would have the better chance of holding he same every time?

As long as you put the 'same' end of the 'v' on the outfeed table each time, it will vary, but get straighter each pass as he described.

I agree that unless that common reference is made results will vary all over the planet.

As I said earlier, I would more likely alternate ends as you described.

JPG40504 wrote:As long as you put the 'same' end of the 'v' on the outfeed table each time, it will vary, but get straighter each pass as he described.

I agree that unless that common reference is made results will vary all over the planet.

As I said earlier, I would more likely alternate ends as you described.

Jpg40504 you miss my point how are you going to hold the v to the jointer table without leaning it to one side or the other? If you have a cupped board and try to joint it crown side against the table it will rock. Of course you can lean it a side against the fence but it must be the same side every time and if that side does not line up the tangent of the cup it will throw the board off.
Always joint with the crown of the cupped board up.

Ed in Tampa wrote:Jpg40504 you miss my point how are you going to hold the v to the jointer table without leaning it to one side or the other? If you have a cupped board and try to joint it crown side against the table it will rock. Of course you can lean it a side against the fence but it must be the same side every time and if that side does not line up the tangent of the cup it will throw the board off.
Always joint with the crown of the cupped board up.

The original article was referring to jointing a bowed board (in contrast to a cupped board). I agree a cupped board should be jointed with the crown of the cup up.

As for bowed boards, the article suggests convex side down (he calls it a reverse rainbow) but I'm not convinced. The more I think of it the more I like Reible's jig for short pieces and for longer pieces I'm going to try the chalk line and the band saw next time and take the bow out before jointing.