Face jointing help please

[Howard Pollack]

I have a Robland jointer-planer with a Byrd head in it. When I try to face joint a board it comes out wedge shaped. Not side to side, but rather the leading edge comes out thinner than the trailing edge. It seems to take many passes to start cutting the trailing part of the board. I assume this is a set-up problem, but I'm not sure. Any suggestions will be appreciated. Thanks -Howard

[Mike Ontko]

There are several responses to other posts on this boards related to this very same question, though it may take some clever combinations of search terms to find them.

Most likely, your outfeed is adjusted a little too low below the height of the cutting edge. This is a little harder to setup on a segmented cutter than it is for a straight blade. It's also possible that your infeed and outfeed surfaces are not completely coplaner, though I'm betting you've already been though that setup process. It's also possible that the board you're starting with is either warped or twisted across its entire length. And, if the boards you're running are long it can be hard to detect the amount of warp (bowing or cupping) or twist without the use of winding sticks or some other reference.

[Andrew Hughes]

I think Mike is on the right track just a little turned around. When the outfeed is too high your wood will bump into the lip of the outfeed table. Pushing the wood up and out of the cut before it gets to the end of the board.
So try lowering it .001 or .002 and see if it gets better.
When its too low you will get snipe on the trailing end.

[Carlos Alvarez]

Howard, you didn't say how much, if any, adjustment you've made on the machine. To me this does sound like the beds are not co-planar. This happened to me and basically the stock was angling down on the outfeed towards the end of the cut.

[Peter Christensen]

I believe it is a technique issue. I think you have a bow shaped board and when you start it takes a deep cut at the start of the pass and by the time the end is on the indeed table it’s not cutting as much. Your next pass does a little less as each succeeding pass does until flat. You end up with your starting end thinner than the trailing end.

Try and put middle of the board over the cutter and push through (half a board on each table). Reverse the board and start from the middle again. If most of the bow is gone start it normally, all on the I feed table. It should end up with both ends about the same thickness and the middle thicker.

[Doug Dawson]

I have a Robland jointer-planer with a Byrd head in it. When I try to face joint a board it comes out wedge shaped. Not side to side, but rather the leading edge comes out thinner than the trailing edge. It seems to take many passes to start cutting the trailing part of the board. I assume this is a set-up problem, but I'm not sure. Any suggestions will be appreciated. Thanks -Howard

With the segmented head, it doesn't matter too much which end of the board you feed into the cutterhead. I assume you've checked that the tables are co-planar, which you can check with a long straightedge. The outfeed table should be level with the top of the cutterhead (again which can be checked with a straightedge.)

If any downward pressure is applied, it should be on the outfeed side. Pressure on the infeed side should be at most slightly downwards, and principally forwards. It might help to _mark_ the _side_ of the board (again with a long straightedge, or a known-straight board) to identify which part along the length of the board needs to be addressed for straightness. Focus on that part of the board, even if it means lowering a middle part of the board onto the cutterhead with a forward motion (a slightly more advanced technique, and controversial to some.)

[Mike Ontko]

I think Mike is on the right track just a little turned around. When the outfeed is too high your wood will bump into the lip of the outfeed table. Pushing the wood up and out of the cut before it gets to the end of the board.
So try lowering it .001 or .002 and see if it gets better.
When its too low you will get snipe on the trailing end.

Thanks for the correction, Andrew. I've been through this on my jointer, but couldn't recall if the starting point of the error was an outfeed that's too high or too low, relative to the blade.

[Howard Pollack]

Thanks everyone, I will systematically work through these suggestions and report the outcome. -Howard